Had my first oil change yesterday (2005 base model 4.7 quad cab) and the guy reached in and turned the key on to get the mileage. The truck did a self check with the tach counting off and the speedometer doing the same, said "c code", did some other strange stuff and then went back to normal. Is this normal after an oil change? If so, how do you get it to do a self diagnostic again? Is "c code" bad or what? Never have seen this happen before and the other Dodge guys I've talked to have never seen this happen to their trucks. The truck runs fine and there are no engine lights on.

Thanks.

 

hope this helps

ACTUATOR TEST
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 indicators are capable of operating as designed. During the actuator test the instrument cluster circuitry will position each of the gauge needles at various calibration points, illuminate all of the segments in the Vacuum Fluorescent Display (VFD) units, turn all of the indicators on and off again, display any Diagnostic Trouble Code (DTC) information, and display the number of ignition key cycles that have occurred since the DTC was detected. It is suggested that a note pad and pencil be used to write down any fault information that is displayed during the test for reference.

Successful completion of the actuator test will confirm that the instrument cluster is operational. However, there may still be a problem with the PCI data bus, the Powertrain Control Module (PCM), the Engine Control Module (ECM), the Front Control Module (FCM), the Transmission Control Module (TCM), the Transfer Case Control Module (TCCM), the Airbag Control Module (ACM), the Controller Anti-lock Brake (CAB), or the hard wired inputs to one of these electronic control modules. Use a diagnostic 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.
Release the odometer/trip odometer switch button.
The instrument cluster will simultaneously begin to illuminate all of the operational segments in both VFD units and perform a bulb check of each operational LED indicator. The VFD segments and LED indicators remain illuminated as each gauge needle is swept to several calibration points and back. If a VFD segment or an LED indicator fails to illuminate, or if a gauge needle fails to sweep through the calibration points and back during this test, the instrument cluster must be replaced. Following these tests, the actuator test will proceed as described in Step 6.
The text “C Code� is displayed in the odometer VFD for about three seconds. If there is no stored fault information, the display will show two pairs of zeroes in the format “00� “00�, which indicate that the display of fault information is done. If there is stored fault information, two sets of two-digit alpha and alpha-numeric fault codes will appear in the odometer display for a three second interval. The first pair of digits represents a Diagnostic Trouble Code (DTC), or fault code for the instrument cluster. The second pair of digits is a counter for the number of ignition key cycles that have occurred since the displayed DTC was set. The instrument cluster will continue to display additional sets of two pairs of digits at three second intervals until all of the stored codes have been displayed, which is again signaled by a code of “00� “00�. Refer to the Instrument Cluster Failure Message table for a description of each fault code that the instrument cluster displays. If an instrument cluster fault is displayed, use a diagnostic scan tool to diagnose the problem. Refer to the appropriate diagnostic information. INSTRUMENT CLUSTER FAILURE MESSAGE
FAULT CODE DESCRIPTION CORRECTION
01 Cargo lamp LED output circuit open load/short to ground. Refer to the appropriate diagnostic information.
02 Cargo lamp LED output circuit overload/short to battery. Refer to the appropriate diagnostic information.
03 Door ajar LED output circuit open load/short to ground. Refer to the appropriate diagnostic information.
04 Door ajar LED output circuit overload/ short to battery. Refer to the appropriate diagnostic information.
05 ETC LED output circuit open load/short to ground. Refer to the appropriate diagnostic information.
06 ETC LED output circuit overload/short to battery. Refer to the appropriate diagnostic information.
07 Seatbelt LED output circuit open load/short to ground. Refer to the appropriate diagnostic information.
08 Seatbelt LED output circuit overload/short to battery. Refer to the appropriate diagnostic information.
09 Air Bag LED output circuit open load/short to ground. Refer to the appropriate diagnostic information.
0A Air Bag LED output circuit overload/short to battery. Refer to the appropriate diagnostic information.
0B BTSI output circuit shorted or open. Refer to the appropriate diagnostic information.
0C PRNDL switch input circuit low. Refer to the appropriate diagnostic information.
0D PRNDL switch input circuit high. Refer to the appropriate diagnostic information.
0E DTCM switch input circuit low. Refer to the appropriate diagnostic information.
0F DTCM switch input circuit high. Refer to the appropriate diagnostic information.
20 Panel dimmer input circuit low. Refer to the appropriate diagnostic information.
21 Panel dimmer input circuit high. Refer to the appropriate diagnostic information.
22 Headlamp switch input circuit shorted. Refer to the appropriate diagnostic information.
23 Headlamp switch input circuit open. Refer to the appropriate diagnostic information.
24 Turn hazard switch input circuit shorted. Refer to the appropriate diagnostic information.
25 Turn hazard swiitch inpot circuit open. Refer to the appropriate diagnostic information.
26 Panel illumination output circuit low/high fault. Refer to the appropriate diagnostic information.
27 Courtesy/dome output circuit shorted or open. Refer to the appropriate diagnostic information.
28 Glovebox/map lamp output circuit shorted or open. Refer to the appropriate diagnostic information.
29 Cargo lamp output circuit shorted or open. Refer to the appropriate diagnostic information.
2B High Beam LED output circuit open load/short to ground. Refer to the appropriate diagnostic information.
2C High Beam LED output circuit overload/short to battery. Refer to the appropriate diagnostic information.
2D Brake LED output circuit open load/short to ground. Refer to the appropriate diagnostic information.
2E Brake LED output circuit overload/short to battery. Refer to the appropriate diagnostic information.
2F Check Gages LED output circuit open load/short to ground. Refer to the appropriate diagnostic information.
30 Check Gages LED output circuit overload/short to battery. Refer to the appropriate diagnostic information.
31 ABS LED output circuit open load/short to ground. Refer to the appropriate diagnostic information.
32 ABS LED output circuit overload/short to battery. Refer to the appropriate diagnostic information.
33 MIL LED output circuit open load/short to ground. Refer to the appropriate diagnostic information.
34 MIL LED output circuit overload/short to battery. Refer to the appropriate diagnostic information.
35 Water in Fuel LED output circuit open load/short to ground. Refer to the appropriate diagnostic information.
36 Water in Fuel LED output circuit overload/short to battery. Refer to the appropriate diagnostic information.
37 Wait to Start LED output circuit open load/short to ground. Refer to the appropriate diagnostic information.
38 Wait to Start LED output circuit overload/short to battery. Refer to the appropriate diagnostic information.
39 Trans Temp LED output circuit open load/short to ground. Refer to the appropriate diagnostic information.
3A Trans Temp LED output circuit overload/short to battery. Refer to the appropriate diagnostic information.
3B Low Fuel LED output circuit open load/short to ground. Refer to the appropriate diagnostic information.
3C Low Fuel LED output circuit overload/short to battery. Refer to the appropriate diagnostic information.
3D BTSI output circuit high fault. Refer to the appropriate diagnostic information.
40 Wiper switch input circuit shorted. Refer to the appropriate diagnostic information.
41 Wiper switch input circuit open. Refer to the appropriate diagnostic information.
42 Wash/beam input circuit shorted. Refer to the appropriate diagnostic information.
60 Passenger door lock switch input circuit shorted. Refer to the appropriate diagnostic information.
61 Passenger door lock switch input circuit open. Refer to the appropriate diagnostic information.
62 Passenger door lock switch input circuit stuck. Refer to the appropriate diagnostic information.
63 Driver door lock switch input circuit shorted. Refer to the appropriate diagnostic information.
64 Driver door lock switch input circuit open. Refer to the appropriate diagnostic information.
65 Driver door lock switch input circuit stuck. Refer to the appropriate diagnostic information.
66 All door lock output circuit shorted to ground or voltage. Refer to the appropriate diagnostic information.
67 All door unlock output circuit shorted to ground or voltage. Refer to the appropriate diagnostic information.
68 Driver door unlock output circuit shorted to ground or voltage. Refer to the appropriate diagnostic information.
6C Driver cylinder lock switch input circuit shorted. Refer to the appropriate diagnostic information.
6E Driver cylinder lock switch input circuit stuck. Refer to the appropriate diagnostic information.
80 Incorrect odometer value found. Refer to the appropriate diagnostic information.
81 Remote radio switch input circuit high. Refer to the appropriate diagnostic information.
82 Remote radio switch stuck. Refer to the appropriate diagnostic information.
A0 Internal module FLASH memory checksum failure. Refer to the appropriate diagnostic information.
A1 Internal module bootloader failure. Refer to the appropriate diagnostic information.
A3 Battery voltage open. Refer to the appropriate diagnostic information.
A4 Ignition Run/Start circuit rationality. Refer to the appropriate diagnostic information.
A5 TCCM messages not received. Refer to the appropriate diagnostic information.
A6 Ignition Unlock circuit rationality. Refer to the appropriate diagnostic information.
A7 VIN checksum error. Refer to the appropriate diagnostic information.
A8 VIN previously stored. Refer to the appropriate diagnostic information.
A9 PCI bus internal failure. Refer to the appropriate diagnostic information.
AA PCM messages not received. Refer to the appropriate diagnostic information.
AB TCM messages not received. Refer to the appropriate diagnostic information.
AC ABS messages not received. Refer to the appropriate diagnostic information.
AD FCM messages not received. Refer to the appropriate diagnostic information.
AE ACM messages not received. Refer to the appropriate diagnostic information.
AF SKIM messages not received. Refer to the appropriate diagnostic information.
B0 RKE fob batteries low. Refer to the appropriate diagnostic information.
B1 RKE module communication link. Refer to the appropriate diagnostic information.
B2 Left Turn LED open circuit. Refer to the appropriate diagnostic information.
B3 Left Turn LED short circuit/overtemp condition. Refer to the appropriate diagnostic information.
B4 Right Turn LED open circuit. Refer to the appropriate diagnostic information.
B5 Right Turn LED sshort circuit/overtemp condition. Refer to the appropriate diagnostic information.
B6 Panel illumination open circuit. Refer to the appropriate diagnostic information.
B7 Dome lamp open circuit. Refer to the appropriate diagnostic information.
B8 Cargo lamp open circuit. Refer to the appropriate diagnostic information.
B9 Door Unlock to Lock all shorted to ground. Refer to the appropriate diagnostic information.
00 Done All Diagnostic Trouble Codes (DTC) have been displayed.


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 over the PCI data bus during the test.
Go back to Step 1 to repeat the test, if necessary.

 

THANKS!! That explains what happened!