2001 Ram-all instruments inop.
Thread Starter
Joined: Apr 2005
Posts: 2
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2001 Ram-all instruments inop.
My Ram 1500 instrument panel has stopped operating. The odometer says "no bus" the speedometer, tachometer doesn't move. All the idiot lights are on all the time. When I first start my truck, the odometer flashes mileage and then says "no bus" (the mileage stays the same everytime I restart the truck. My friend has a "Snap-on" datalink. Hooked to the OBDII port it showed no codes, had a tach signal and while driving showed MPH. I read the thread that Parts/Service wrote in response to general47's complaint of "malfunction light and shifting" on 4/4 and am about to try the actuator test. I read the Air bag warning and kind of got nervous about deploying it. Is there anyone experiencing the same problem? Any help would be appreciated. Thanks
Champion
Joined: Mar 2004
Posts: 2,703
Likes: 2
From: Bremen, GA.
RE: 2001 Ram-all instruments inop.
I know that this is long but hope it helps............
DIAGNOSIS AND TESTING - INSTRUMENT CLUSTER
If all of the instrument cluster gauges and/or indicators are inoperative, refer to . If an individual gauge or Chrysler Collision Detection (CCD) data bus message-controlled indicator is inoperative, refer to . If an individual hard wired indicator is inoperative, refer to the diagnosis and testing information for that specific indicator. If the instrument cluster chime warning request function is inoperative, refer to . If the instrument cluster illumination lighting is inoperative, refer to . If the instrument cluster Vacuum-Fluorescent Display (VFD) dimmer service is inoperative, use a DRBIII® scan tool to diagnose the problem. Refer to the appropriate diagnostic procedures. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.
NOTE: Certain indicators in this instrument cluster are programmable. This feature allows those indicators to be activated or deactivated with a DRBIII® scan tool for compatibility with certain optional equipment. If the problem being diagnosed involves improper illumination of the upshift indicator, use a DRBIII® scan tool to be certain that the instrument cluster has been programmed with the proper vehicle equipment option settings.
PRELIMINARY DIAGNOSIS
WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
If the indicators operate, but none of the gauges operate, go to Step 2. If all of the gauges and the CCD data bus message-controlled indicators are inoperative, go to Step 5.
Check the fused B(+) fuse (Fuse 14 - 10 ampere) in the Junction Block (JB). If OK, go to Step 3. If not OK, repair the shorted circuit or component as required and replace the faulty fuse.
Check for battery voltage at the fused B(+) fuse (Fuse 14 - 10 ampere) in the JB. If OK, go to Step 4. If not OK, repair the open fused B(+) circuit between the JB and the Power Distribution Center (PDC) as required.
Disconnect and isolate the battery negative cable. Remove the instrument cluster. Connect the battery negative cable. Check for battery voltage at the fused B(+) circuit cavity of the instrument panel wire harness connector (Connector C1) for the instrument cluster. If OK, refer to . If not OK, repair the open fused B(+) circuit between the instrument cluster and the JB as required.
Check the fused ignition switch output (st-run) fuse (Fuse 17 - 10 ampere) in the JB. If OK, go to Step 6. If not OK, repair the shorted circuit or component as required and replace the faulty fuse.
Turn the ignition switch to the On position. Check for battery voltage at the fused ignition switch output (st-run) fuse (Fuse 17 - 10 ampere) in the JB. If OK, go to Step 7. If not OK, repair the open fused ignition switch output (st-run) circuit between the instrument cluster and the JB as required.
Turn the ignition switch to the Off position. Disconnect and isolate the battery negative cable. Reinstall the instrument cluster. Reconnect the battery negative cable. Turn the ignition switch to the On position. Set the park brake. The brake indicator in the instrument cluster should light. If OK, go to Step 8. If not OK, go to Step 9.
Turn the ignition switch to the Off position. Turn on the park lamps and adjust the panel lamps dimmer thumbwheel in the headlamp switch to the full bright position. The cluster illumination lamps should light. If OK, go to Step 10. If not OK, repair the open ground circuit (Z3) between the instrument cluster and ground (G201) as required.
Turn the ignition switch to the Off position. Disconnect and isolate the battery negative cable. Remove the instrument cluster. Connect the battery negative cable. Turn the ignition switch to the On position. Check for battery voltage at the fused ignition switch output (st-run) circuit cavity of the instrument panel wire harness connector (Connector C1). If OK, refer to . If not OK, repair the open fused ignition switch output (st-run) circuit between the instrument cluster and the JB as required.
Disconnect and isolate the battery negative cable. Remove the instrument cluster. Check for continuity between the ground circuit (Z2) cavity of the instrument panel wire harness connector (Connector C1) and a good ground. There should be continuity. If OK, refer to . If not OK, repair the open ground circuit to ground (G200) as required.
ACTUATOR TEST
WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
The instrument cluster actuator test will put the instrument cluster into its self-diagnostic mode. In this mode the instrument cluster can perform a self-diagnostic test that will confirm that the instrument cluster circuitry, the gauges, and the CCD data bus message-controlled indicators are capable of operating as designed. During the actuator test the instrument cluster circuitry position each of the gauge needles at various calibration points, illuminate each of the segments in the Vacuum-Fluorescent Display (VFD), and turn all of the CCD data bus message-controlled indicators on and off.
Successful completion of the actuator test will confirm that the instrument cluster is operational. However, there may still be a problem with the CCD data bus, the Powertrain Control Module (PCM), the Engine Control Module (ECM), the Airbag Control Module (ACM), the Controller Anti-lock Brake (CAB), or the inputs to one of these electronic control modules. Use a DRBIII® scan tool to diagnose these components. Refer to the appropriate diagnostic information.
Begin the test with the ignition switch in the Off position.
Depress the odometer/trip odometer switch button.
While still holding the odometer/trip odometer switch button depressed, turn the ignition switch to the On position, but do not start the engine.
Keep the odometer/trip odometer switch button depressed for about ten seconds, until CHEC appears in the odometer display, then release the odometer/trip odometer switch button.
A series of three-digit numeric failure messages may appear in the odometer display, depending upon the failure mode. If a failure message appears, refer to the Instrument Cluster Failure Message chart for the description and proper correction. If no failure message appears, the actuator test will proceed as described in Step 16. INSTRUMENT CLUSTER FAILURE MESSAGE
Message Description Correction
110 A failure has been identified in the cluster CPU, RAM, or EEPROM. 1. Replace the faulty cluster.
900 The CCD data bus is not operational. 1. Check the CCD data bus connections at the cluster.
2. Check the cluster fuses.
3. Check the CCD data bus bias.
4. Check the CCD data bus voltage.
5. Check the CCD data bus terminations.
920 The cluster is not receiving a vehicle speed message from the PCM. 1. Check the PCM software level and reflash if required.
2. Use a DRBIII® scan tool to verify that the vehicle speed message is being sent by the PCM.
921 The cluster is not receiving a distance pulse message from the PCM. 1. Check the PCM software level and reflash if required.
2. Use a DRBIII® scan tool to verify that the distance pulse message is being sent by the PCM.
940 The cluster is not receiving an airbag lamp-on message from the ACM. 1. Check the CCD data bus connections at the ACM.
2. Check the ACM fuse.
950 The cluster is not receiving an ABS lamp-on message from the CAB. 1. Check the CCD data bus connections at the CAB.
2. Check the CAB fuse.
999 An error has been discovered. 1. Record the failure message.
2. Depress the trip odometer reset button to continue the Self-Diagnostic Test.
The instrument cluster will begin the Vacuum Fluorescent Display (VFD) walking segment test. This test will require the operator to visually inspect each VFD segment as it is displayed to determine a pass or fail condition. First, all of the segments will be illuminated at once; then, each individual segment of the VFD will be illuminated in sequence. If any segment in the display fails to illuminate, repeat the test to confirm the failure. If the failure is confirmed, replace the faulty instrument cluster. Following completion of the VFD walking segment test, the actuator test will proceed as described in Step 17.
The instrument cluster will perform a bulb check of each indicator that the instrument cluster circuitry controls. If the wait-to-start indicator does not illuminate during this test, the instrument cluster should be removed. However, check that the incandescent bulb is not faulty and that the bulb holder is properly installed on the instrument cluster electronic circuit board before considering instrument cluster replacement. If the bulb and bulb holder check OK, replace the faulty instrument cluster. Each of the remaining instrument cluster circuitry controlled indicators except the cruise indicator are illuminated by a Light Emitting Diode (LED). If an LED or the cruise indicator in the VFD, fails to illuminate during this test, the instrument cluster must be replaced. Following the bulb check test, the actuator test will proceed as described in Step 18.
The instrument cluster will perform a gauge actuator test. In this test the instrument cluster circuitry positions each of the gauge needles at three different calibration points, then returns the gauge needles to their relaxed positions. If an individual gauge does not respond properly, or does not respond at all during the gauge actuator test, the instrument cluster should be removed. However, check that the gauge terminal pins are properly inserted through the spring-clip terminal pin receptacles on the instrument cluster electronic circuit board before considering instrument cluster replacement. If the gauge terminal connections are OK, replace the faulty instrument cluster.
The actuator test is now completed. The instrument cluster will automatically exit the self-diagnostic mode and return to normal operation at the completion of the test, if the ignition switch is turned to the Off position during the test, or if a vehicle speed message indicating that the vehicle is moving is received from the PCM on the CCD data bus during the test.
Go back to Step 11 to repeat the test, if required.
CHIME WARNING REQUEST DIAGNOSIS
Before performing this test, complete the testing of the seat belt switch and the Central Timer Module (CTM). (Refer to 8 - ELECTRICAL/RESTRAINTS/SEAT BELT SWITCH - DIAGNOSIS AND TESTING) and (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/BODY CONTROL/CENTRAL TIMER MODULE - DIAGNOSIS AND TESTING). The diagnosis found here consists of confirming the viability of the hard wired tone request circuit between the instrument cluster and the Central Timer Module (CTM). For diagnosis of the CCD data bus and the data bus message inputs that cause the instrument cluster to issue a request for chime service, a DRBIII® scan tool is required. Refer to the appropriate diagnostic information.
WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
Disconnect and isolate the battery negative cable. Remove the instrument cluster from the instrument panel. Move the CTM away from its mounting bracket far enough to access the instrument panel wire harness connector(s) for the CTM. Disconnect the instrument panel wire harness connector (Connector C1) from the CTM connector receptacle.
Check for continuity between the tone request circuit cavity of the instrument panel wire harness connector (Connector C2) for the instrument cluster and a good ground. There should be no continuity. If OK, go to Step 23. If not OK, repair the shorted tone request circuit between the instrument cluster and the CTM as required.
Check for continuity between the tone request circuit cavities of the instrument panel wire harness connector (Connector C2) for the instrument cluster and the instrument panel wire harness connector (Connector C1) for the CTM. There should be continuity. If OK, replace the faulty instrument cluster. If not OK, repair the open tone request circuit between the instrument cluster and the CTM as required.
CLUSTER ILLUMINATION DIAGNOSIS
The diagnosis found here addresses an inoperative instrument cluster illumination lamp condition. If the problem being diagnosed is a single inoperative illumination lamp, be certain that the bulb and bulb holder unit are properly installed in the instrument cluster electronic circuit board. If no installation problems are found replace the faulty bulb and bulb holder unit. If all of the cluster illumination lamps are inoperative and the problem being diagnosed includes inoperative exterior lighting controlled by the headlamp switch, that system needs to be repaired first. (Refer to 8 - ELECTRICAL/LAMPS/LIGHTING - EXTERIOR/HEADLAMP - DIAGNOSIS AND TESTING). If no exterior lighting system problems are found, the following procedure will help locate a short or open in the cluster illumination lamp circuit. If the problem being diagnosed involves a lack of dimming control for the odometer/trip odometer Vacuum Fluorescent Display (VFD), but all of the other cluster illumination lamps can be dimmed, test and repair the day brightness circuit between the instrument cluster and the headlamp switch as required. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
Check the instrument panel dimmer fuse (Fuse 5 - 5 ampere) in the Junction Block (JB). If OK, go to Step 25. If not OK, repair the shorted circuit or component as required and replace the faulty fuse.
Turn the exterior lamps On with the headlamp switch. Rotate the headlamp switch panel lamps dimmer thumbwheel upward to just before the interior lamps detent. Check for battery voltage at the panel lamps dimmer fuse (Fuse 5 - 5 ampere) in the JB. Rotate the panel lamps dimmer thumbwheel downward while observing the test voltmeter. The reading should go from battery voltage to zero volts. If OK, go to Step 26. If not OK, repair the open panel lamps dimmer switch signal circuit between the headlamp switch and the JB as required.
Turn the exterior lamps Off. Disconnect and isolate the battery negative cable. Remove the instrument cluster. Remove the instrument panel dimmer fuse (Fuse 5 - 5 ampere) from the JB. Probe the fused panel lamps dimmer switch signal circuit cavity of the instrument panel wire harness connector (Connector C2) for the instrument cluster. Check for continuity to a good ground. There should be no continuity. If OK, go to Step 27. If not OK, repair the shorted fused panel lamps dimmer switch signal circuit between the instrument cluster and the JB as required.
Reinstall the instrument panel dimmer fuse (Fuse 5 - 5 ampere) in the JB. Reconnect the battery negative cable. Turn the exterior lamps On with the headlamp switch. Rotate the headlamp switch panel lamps dimmer thumbwheel upward to just before the interior lamps detent. Check for battery voltage at the fused panel lamps dimmer switch signal circuit cavity of the instrument panel wire harness connector (Connector C2) for the instrument cluster. If OK, replace the faulty bulb and bulb holder units. If not OK, repair the open fused panel lamps dimmer switch signal circuit between the instrument cluster and the JB as required.
DIAGNOSIS AND TESTING - INSTRUMENT CLUSTER
If all of the instrument cluster gauges and/or indicators are inoperative, refer to . If an individual gauge or Chrysler Collision Detection (CCD) data bus message-controlled indicator is inoperative, refer to . If an individual hard wired indicator is inoperative, refer to the diagnosis and testing information for that specific indicator. If the instrument cluster chime warning request function is inoperative, refer to . If the instrument cluster illumination lighting is inoperative, refer to . If the instrument cluster Vacuum-Fluorescent Display (VFD) dimmer service is inoperative, use a DRBIII® scan tool to diagnose the problem. Refer to the appropriate diagnostic procedures. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.
NOTE: Certain indicators in this instrument cluster are programmable. This feature allows those indicators to be activated or deactivated with a DRBIII® scan tool for compatibility with certain optional equipment. If the problem being diagnosed involves improper illumination of the upshift indicator, use a DRBIII® scan tool to be certain that the instrument cluster has been programmed with the proper vehicle equipment option settings.
PRELIMINARY DIAGNOSIS
WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
If the indicators operate, but none of the gauges operate, go to Step 2. If all of the gauges and the CCD data bus message-controlled indicators are inoperative, go to Step 5.
Check the fused B(+) fuse (Fuse 14 - 10 ampere) in the Junction Block (JB). If OK, go to Step 3. If not OK, repair the shorted circuit or component as required and replace the faulty fuse.
Check for battery voltage at the fused B(+) fuse (Fuse 14 - 10 ampere) in the JB. If OK, go to Step 4. If not OK, repair the open fused B(+) circuit between the JB and the Power Distribution Center (PDC) as required.
Disconnect and isolate the battery negative cable. Remove the instrument cluster. Connect the battery negative cable. Check for battery voltage at the fused B(+) circuit cavity of the instrument panel wire harness connector (Connector C1) for the instrument cluster. If OK, refer to . If not OK, repair the open fused B(+) circuit between the instrument cluster and the JB as required.
Check the fused ignition switch output (st-run) fuse (Fuse 17 - 10 ampere) in the JB. If OK, go to Step 6. If not OK, repair the shorted circuit or component as required and replace the faulty fuse.
Turn the ignition switch to the On position. Check for battery voltage at the fused ignition switch output (st-run) fuse (Fuse 17 - 10 ampere) in the JB. If OK, go to Step 7. If not OK, repair the open fused ignition switch output (st-run) circuit between the instrument cluster and the JB as required.
Turn the ignition switch to the Off position. Disconnect and isolate the battery negative cable. Reinstall the instrument cluster. Reconnect the battery negative cable. Turn the ignition switch to the On position. Set the park brake. The brake indicator in the instrument cluster should light. If OK, go to Step 8. If not OK, go to Step 9.
Turn the ignition switch to the Off position. Turn on the park lamps and adjust the panel lamps dimmer thumbwheel in the headlamp switch to the full bright position. The cluster illumination lamps should light. If OK, go to Step 10. If not OK, repair the open ground circuit (Z3) between the instrument cluster and ground (G201) as required.
Turn the ignition switch to the Off position. Disconnect and isolate the battery negative cable. Remove the instrument cluster. Connect the battery negative cable. Turn the ignition switch to the On position. Check for battery voltage at the fused ignition switch output (st-run) circuit cavity of the instrument panel wire harness connector (Connector C1). If OK, refer to . If not OK, repair the open fused ignition switch output (st-run) circuit between the instrument cluster and the JB as required.
Disconnect and isolate the battery negative cable. Remove the instrument cluster. Check for continuity between the ground circuit (Z2) cavity of the instrument panel wire harness connector (Connector C1) and a good ground. There should be continuity. If OK, refer to . If not OK, repair the open ground circuit to ground (G200) as required.
ACTUATOR TEST
WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
The instrument cluster actuator test will put the instrument cluster into its self-diagnostic mode. In this mode the instrument cluster can perform a self-diagnostic test that will confirm that the instrument cluster circuitry, the gauges, and the CCD data bus message-controlled indicators are capable of operating as designed. During the actuator test the instrument cluster circuitry position each of the gauge needles at various calibration points, illuminate each of the segments in the Vacuum-Fluorescent Display (VFD), and turn all of the CCD data bus message-controlled indicators on and off.
Successful completion of the actuator test will confirm that the instrument cluster is operational. However, there may still be a problem with the CCD data bus, the Powertrain Control Module (PCM), the Engine Control Module (ECM), the Airbag Control Module (ACM), the Controller Anti-lock Brake (CAB), or the inputs to one of these electronic control modules. Use a DRBIII® scan tool to diagnose these components. Refer to the appropriate diagnostic information.
Begin the test with the ignition switch in the Off position.
Depress the odometer/trip odometer switch button.
While still holding the odometer/trip odometer switch button depressed, turn the ignition switch to the On position, but do not start the engine.
Keep the odometer/trip odometer switch button depressed for about ten seconds, until CHEC appears in the odometer display, then release the odometer/trip odometer switch button.
A series of three-digit numeric failure messages may appear in the odometer display, depending upon the failure mode. If a failure message appears, refer to the Instrument Cluster Failure Message chart for the description and proper correction. If no failure message appears, the actuator test will proceed as described in Step 16. INSTRUMENT CLUSTER FAILURE MESSAGE
Message Description Correction
110 A failure has been identified in the cluster CPU, RAM, or EEPROM. 1. Replace the faulty cluster.
900 The CCD data bus is not operational. 1. Check the CCD data bus connections at the cluster.
2. Check the cluster fuses.
3. Check the CCD data bus bias.
4. Check the CCD data bus voltage.
5. Check the CCD data bus terminations.
920 The cluster is not receiving a vehicle speed message from the PCM. 1. Check the PCM software level and reflash if required.
2. Use a DRBIII® scan tool to verify that the vehicle speed message is being sent by the PCM.
921 The cluster is not receiving a distance pulse message from the PCM. 1. Check the PCM software level and reflash if required.
2. Use a DRBIII® scan tool to verify that the distance pulse message is being sent by the PCM.
940 The cluster is not receiving an airbag lamp-on message from the ACM. 1. Check the CCD data bus connections at the ACM.
2. Check the ACM fuse.
950 The cluster is not receiving an ABS lamp-on message from the CAB. 1. Check the CCD data bus connections at the CAB.
2. Check the CAB fuse.
999 An error has been discovered. 1. Record the failure message.
2. Depress the trip odometer reset button to continue the Self-Diagnostic Test.
The instrument cluster will begin the Vacuum Fluorescent Display (VFD) walking segment test. This test will require the operator to visually inspect each VFD segment as it is displayed to determine a pass or fail condition. First, all of the segments will be illuminated at once; then, each individual segment of the VFD will be illuminated in sequence. If any segment in the display fails to illuminate, repeat the test to confirm the failure. If the failure is confirmed, replace the faulty instrument cluster. Following completion of the VFD walking segment test, the actuator test will proceed as described in Step 17.
The instrument cluster will perform a bulb check of each indicator that the instrument cluster circuitry controls. If the wait-to-start indicator does not illuminate during this test, the instrument cluster should be removed. However, check that the incandescent bulb is not faulty and that the bulb holder is properly installed on the instrument cluster electronic circuit board before considering instrument cluster replacement. If the bulb and bulb holder check OK, replace the faulty instrument cluster. Each of the remaining instrument cluster circuitry controlled indicators except the cruise indicator are illuminated by a Light Emitting Diode (LED). If an LED or the cruise indicator in the VFD, fails to illuminate during this test, the instrument cluster must be replaced. Following the bulb check test, the actuator test will proceed as described in Step 18.
The instrument cluster will perform a gauge actuator test. In this test the instrument cluster circuitry positions each of the gauge needles at three different calibration points, then returns the gauge needles to their relaxed positions. If an individual gauge does not respond properly, or does not respond at all during the gauge actuator test, the instrument cluster should be removed. However, check that the gauge terminal pins are properly inserted through the spring-clip terminal pin receptacles on the instrument cluster electronic circuit board before considering instrument cluster replacement. If the gauge terminal connections are OK, replace the faulty instrument cluster.
The actuator test is now completed. The instrument cluster will automatically exit the self-diagnostic mode and return to normal operation at the completion of the test, if the ignition switch is turned to the Off position during the test, or if a vehicle speed message indicating that the vehicle is moving is received from the PCM on the CCD data bus during the test.
Go back to Step 11 to repeat the test, if required.
CHIME WARNING REQUEST DIAGNOSIS
Before performing this test, complete the testing of the seat belt switch and the Central Timer Module (CTM). (Refer to 8 - ELECTRICAL/RESTRAINTS/SEAT BELT SWITCH - DIAGNOSIS AND TESTING) and (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES/BODY CONTROL/CENTRAL TIMER MODULE - DIAGNOSIS AND TESTING). The diagnosis found here consists of confirming the viability of the hard wired tone request circuit between the instrument cluster and the Central Timer Module (CTM). For diagnosis of the CCD data bus and the data bus message inputs that cause the instrument cluster to issue a request for chime service, a DRBIII® scan tool is required. Refer to the appropriate diagnostic information.
WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
Disconnect and isolate the battery negative cable. Remove the instrument cluster from the instrument panel. Move the CTM away from its mounting bracket far enough to access the instrument panel wire harness connector(s) for the CTM. Disconnect the instrument panel wire harness connector (Connector C1) from the CTM connector receptacle.
Check for continuity between the tone request circuit cavity of the instrument panel wire harness connector (Connector C2) for the instrument cluster and a good ground. There should be no continuity. If OK, go to Step 23. If not OK, repair the shorted tone request circuit between the instrument cluster and the CTM as required.
Check for continuity between the tone request circuit cavities of the instrument panel wire harness connector (Connector C2) for the instrument cluster and the instrument panel wire harness connector (Connector C1) for the CTM. There should be continuity. If OK, replace the faulty instrument cluster. If not OK, repair the open tone request circuit between the instrument cluster and the CTM as required.
CLUSTER ILLUMINATION DIAGNOSIS
The diagnosis found here addresses an inoperative instrument cluster illumination lamp condition. If the problem being diagnosed is a single inoperative illumination lamp, be certain that the bulb and bulb holder unit are properly installed in the instrument cluster electronic circuit board. If no installation problems are found replace the faulty bulb and bulb holder unit. If all of the cluster illumination lamps are inoperative and the problem being diagnosed includes inoperative exterior lighting controlled by the headlamp switch, that system needs to be repaired first. (Refer to 8 - ELECTRICAL/LAMPS/LIGHTING - EXTERIOR/HEADLAMP - DIAGNOSIS AND TESTING). If no exterior lighting system problems are found, the following procedure will help locate a short or open in the cluster illumination lamp circuit. If the problem being diagnosed involves a lack of dimming control for the odometer/trip odometer Vacuum Fluorescent Display (VFD), but all of the other cluster illumination lamps can be dimmed, test and repair the day brightness circuit between the instrument cluster and the headlamp switch as required. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
Check the instrument panel dimmer fuse (Fuse 5 - 5 ampere) in the Junction Block (JB). If OK, go to Step 25. If not OK, repair the shorted circuit or component as required and replace the faulty fuse.
Turn the exterior lamps On with the headlamp switch. Rotate the headlamp switch panel lamps dimmer thumbwheel upward to just before the interior lamps detent. Check for battery voltage at the panel lamps dimmer fuse (Fuse 5 - 5 ampere) in the JB. Rotate the panel lamps dimmer thumbwheel downward while observing the test voltmeter. The reading should go from battery voltage to zero volts. If OK, go to Step 26. If not OK, repair the open panel lamps dimmer switch signal circuit between the headlamp switch and the JB as required.
Turn the exterior lamps Off. Disconnect and isolate the battery negative cable. Remove the instrument cluster. Remove the instrument panel dimmer fuse (Fuse 5 - 5 ampere) from the JB. Probe the fused panel lamps dimmer switch signal circuit cavity of the instrument panel wire harness connector (Connector C2) for the instrument cluster. Check for continuity to a good ground. There should be no continuity. If OK, go to Step 27. If not OK, repair the shorted fused panel lamps dimmer switch signal circuit between the instrument cluster and the JB as required.
Reinstall the instrument panel dimmer fuse (Fuse 5 - 5 ampere) in the JB. Reconnect the battery negative cable. Turn the exterior lamps On with the headlamp switch. Rotate the headlamp switch panel lamps dimmer thumbwheel upward to just before the interior lamps detent. Check for battery voltage at the fused panel lamps dimmer switch signal circuit cavity of the instrument panel wire harness connector (Connector C2) for the instrument cluster. If OK, replace the faulty bulb and bulb holder units. If not OK, repair the open fused panel lamps dimmer switch signal circuit between the instrument cluster and the JB as required.
Amateur
Joined: Feb 2004
Posts: 41
Likes: 0
From: Philippi, WV
RE: 2001 Ram-all instruments inop.
I have a 2002 Ram 1500. I did the cluster test and get the following codes. Could you help me interpret them?
23 36
A4 27
AA 38
00 00
I also have a P1491 code popping up and was wondering what I need to check in the radiator fan relay or what I need to do to fix it?
23 36
A4 27
AA 38
00 00
I also have a P1491 code popping up and was wondering what I need to check in the radiator fan relay or what I need to do to fix it?
