Check Engine Light - DTC P1740 - resolved...for now
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Amateur
Joined: Jul 2006
Posts: 42
Likes: 0
Check Engine Light - DTC P1740 - resolved...for now
I've got a 2000 Dakota RT. The check engine light came on and it ended up being a code P1740. Overdrive stopped working.
I just wanted to pass along this info. This code apparently could be related to bad torque converter, OD and/or TCC solenoid, etc. I read that it also can be caused by a number of other things including sludge in the transmission. The mechanic suggested a full $1700 rebuild. I opted for a trans flush first. Overdrive started working again. I cleared the code by disconnecting the negative, then positive battery terminals. I know I only needed to do the negative, but both needed cleaning. The on/off trick did not clear the code for me. Maybe I did it wrong.
Anyway, it's only been a day, but no check engine light now and overdrive works. So, I'm keeping my fingers crossed and hoping it was just sludge. I wish the mechanic would not have jumped straight to the big bucks option though.
fyi...
I just wanted to pass along this info. This code apparently could be related to bad torque converter, OD and/or TCC solenoid, etc. I read that it also can be caused by a number of other things including sludge in the transmission. The mechanic suggested a full $1700 rebuild. I opted for a trans flush first. Overdrive started working again. I cleared the code by disconnecting the negative, then positive battery terminals. I know I only needed to do the negative, but both needed cleaning. The on/off trick did not clear the code for me. Maybe I did it wrong.
Anyway, it's only been a day, but no check engine light now and overdrive works. So, I'm keeping my fingers crossed and hoping it was just sludge. I wish the mechanic would not have jumped straight to the big bucks option though.
fyi...
Amateur
Joined: Jul 2013
Posts: 45
Likes: 1
From: Rochester NY
I have a 2000 base model and also had the code pop on. I checked the fluid and was just a bit low, so added 1/2 quart. I also pulled the battery connections to clear the mil light, which worked for 1-1/2 weeks. I did not have any problems with the OD not working, as far as I can tell. The code is now on again, I also have been told by 2 different shops the transmission will need a rebuild for $1700. The truck only has 90,000, so I will start first with changing the fluid and filter to see if there is any metal shavings in the pan. Probable will take it to the dodge dealer to have checked according to the latest TSB on this problem. Hope its not a total rebuild.
Symptom:
P1740-TCC OR O/D SOLENOID PERFORMANCE
When Monitored and Set Condition:
P1740-TCC OR O/D SOLENOID PERFORMANCE
When Monitored: The Torque Converter Clutch (TCC) and Overdrive Clutch (O/D) will be
tested each time the PCM requests TCC engagement in 3rd gear and O/D.
Set Condition: The DTC will set if the expected engine rpm to output shaft speed rpm
ratio is not achieved during TCC and/or O/D engagement. This indicates malfunctioning
torque converter or overdrive clutch.
POSSIBLE CAUSES
TORQUE CONVERTER
INTERMITTENT 3-4 SOLENOID
INTERNAL TRANSMISSION PROBLEM - OD CLUTCH/SEALS OR VALVE BODY CONTAMINATION
OIL BURNT OR OIL PAN HAS EXCESSIVE DEBRIS
COOLER FLOW RESTRICTED
OIL PUMP/SHAFT
OIL PUMP/SHAFT
TRANSMISSION FLUID LEVEL AND CONDITION
INTERMITTENT GOV PRESSURE SENSOR SIGNAL
INTERMITTENT TCC SOLENOID
INTERNAL PROBLEM OR TCC SOLENOID
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRB, read DTCs.
Is the Specific Good Trip Counter for P-1740 displayed and equal to 0?
All
Yes ® Go To 2
No ® Go To 16
TEST ACTION APPLICABILITY
2 The following vehicle states (conditions) must be met before Test Driving Vehicle.
Transmission Control Relay DTCs must not be present.
Misfire DTCs must not be present.
P0753-TRANSMISSION 3-4 SHIFT SOLENOID/TRANSMISSION RELAY CIRCUIT
DTC must not be present.
P0743-TORQUE CONVERTER CLUTCH SOLENOID DTC must not be present.
Throttle Position Sensor DTCs must not be present.
P1899-P/N SWITCH STUCK DTC must not be present.
Repair all Engine RPM DTCs.
P0340-NO CAM SIGNAL AT PCM DTC must not be present.
Output Shaft Speed DTCs must not be present.
The fuel level must not be low.
Move the Transfer Case Lever out of Low Range.
Disengage the PTO.
Warm the transmission temperature to above 0°C (32°F).
The transmission fluid level must be full and must not contain any debris.
With the DRB, build a custom display to monitor Engine RPM, Output Shaft Speed,
TCC Solenoid, O/D Solenoid, Gear Status and Throttle Position.
Note: The display will be used to monitor the operation of the components.
Set the Overdrive to the off position.
Test drive the vehicle. Attain a steady speed of 89 kmh (55 MPH) with a minimum of
1.15 volts throttle opening for 20 seconds. Ensure the transmission shifts to 3rd gear
and the torque converter clutch is engaged.
Monitor shift patterns while the vehicle is upshifting to vehicle speed.
Is the engine rpm within 60 rpm of the Output Shaft Speed rpm?
All
Yes ® Go To 3
No ® Go To 8
3 Test drive the vehicle.
Attain a steady speed of 89 kmh (55 MPH), ensuring the TCC is engaged, then
engage the Overdrive.
Note: Output Shaft Speed x 0.69 = Expected Engine RPM
Did the engine rpm drop to 0.69 of the Output Shaft Speed?
All
Yes ® Go To 4
No ® Go To 9
4 Turn the ignition off.
Connect a 0 - 2068 KPa (0 - 300 PSI) pressure gauge to the Overdrive Clutch test port.
Connect another 0 - 2068 KPa (0 - 300 PSI) pressure gauge to the Governor Pressure
test port.
Start the engine and allow the transmission temperature to rise to normal operating
temperature.
Caution: Apply the parking brake.
Place the gear selector in Drive.
While observing the pressure gauges, select 4th gear from Gov and 3-4 Shift Valve
Test with the DRB.
Note: The governor pressure should rise to above 138 KPa (20 PSI). Shortly
after this, the O/D pressure should rise to above 276 KPa (40 PSI).
Did the pressure act as described?
All
Yes ® Go To 5
No ® Go To 7
TEST ACTION APPLICABILITY
5 Turn the ignition off.
Remove the transmission oil pan and inspect for excessive debris and burnt oil.
Is the oil burnt or does the transmission oil pan contain excessive debris?
All
Yes ® Repair the internal transmission problem in accordance with the
Service Information.
Perform the Transmission DTC Verification test.
No ® Go To 6
6 The vehicle must be driven (road load) to set this code. Drive the vehicle 4 times from
0 to 89 kmh (0 to 55 MPH) with a constant 20 % throttle position through all gears.
Stop the vehicle, shut the engine off and then repeat the procedure.
At this time, the conditions required to set the DTC are not present.
Note: Use the Freeze Frame Data to help duplicate the conditions that set
the DTC. Pay particular attention to the DTC set conditions, such as, VSS,
MAP, ECT, and Load.
Note: Visually inspect the related wiring harness. Look for any chafed,
pierced, pinched, or partially broken wires.
Note: Visually inspect the related wiring harness connectors. Look for
broken, bent, pushed out, or corroded terminals.
Note: Refer to any technical service bulletins that may apply.
Were any problems found?
All
Yes ® Repair as necessary. Pay particular attention to contamination in
the 3-4 Shift Solenoid.
Perform the Transmission DTC Verification test.
No ® Test Complete.
7 Turn the ignition off.
Replace the 3-4 Shift Solenoid (part of the Transmission Solenoid Assembly) in
accordance with the Service Information.
Connect a 0 - 2068 KPa (0 - 300 PSI) pressure gauge to the Overdrive Clutch test port.
Connect another 0 - 2068 KPa (0 - 300 PSI) pressure gauge to the Governor Pressure
test port.
Start the engine and allow the transmission temperature to reach normal operating
temperature.
Caution: Apply the parking brake.
Place the gear selector in Drive.
While observing the pressure gauges, actuate the 3-4 Shift Solenoid with the DRB.
Note: The governor pressure should rise to above 138 KPa (20 PSI). Shortly
after this, the O/D pressure should rise to above 276 KPa (40 PSI).
Did the pressure act as described?
All
Yes ® Test Complete.
No ® Overhaul the transmission in accordance with the Service Information.
Pay extra attention to Seals and Clutches related to the
OD Clutch and check for Valve Body contamination.
Perform the Transmission DTC Verification test.
8 Start the engine.
Allow the transmission to reach normal operating temperature.
Check the transmission fluid level and condition.
Is the fluid level correct and the fluid condition OK?
All
Yes ® Go To 9
No ® Repair as necessary.
TEST ACTION APPLICABILITY
9 Start the engine.
With the DRB, perform the TCC System Test.
Did the engine stall?
All
Yes ® Go To 10
No ® Go To 14
10 Start the engine.
Perform the Gov and 3-4 Shift Valve System Test. Select 4th gear.
Did the engine stall?
All
Yes ® Go To 11
No ® Go To 12
11 Turn the ignition off.
Replace the TCC Solenoid (part of the Transmission Solenoid Assembly) in accordance
with the Service Information.
Perform the Gov and 3-4 Shift Valve System Test.
Wtih the DRB, select 4th gear.
Did the engine stall?
All
Yes ® Repair the internal transmission problem in accordance with the
Service Information. Check for blocked passage(s).
Perform Transmission DTC Verification Test
No-Test Complete
Test Complete.
12 Turn the ignition off.
Remove the transmission oil pump and inspect the reaction shaft, input shaft and
input shaft seals.
Are any of the parts worn or damaged?
All
Yes ® Repair or replace the parts as necessary. Replace the Torque
Converter.
Perform the Transmission Verification Test - Ver 1.
No ® Go To 13
13 At this time, the conditions required to set the DTC are not present.
Note: Use the Freeze Frame Data to help duplicate the conditions that set
the DTC. Pay particular attention to the DTC set conditions, such as, VSS,
MAP, ECT, and Load.
Note: Visually inspect the related wiring harness. Look for any chafed,
pierced, pinched, or partially broken wires.
Note: Visually inspect the related wiring harness connectors. Look for
broken, bent, pushed out, or corroded terminals.
Note: Refer to any technical service bulletins that may apply.
Were any problems found?
All
Yes ® Repair as necessary.
Perform Transmission DTC Verification Test
NO- TEST COMPLETE
Test Complete.
TEST ACTION APPLICABILITY
14 Turn the ignition off.
Connect a pressure gauge to the transmission cooler out port with a 9T9 connector.
Start the engine.
With the DRB, perform TCC System Test.
Did the cooler out pressure increase when the TCC was actuated?
All
Yes ® Go To 15
No ® Repair the valve body in accordance with the Service Information.
Check for blockages or leaks in the TCC hydraulic circuit.
Perform the Transmission Verification Test - Ver 1.
15 Turn the ignition off.
Remove the transmission oil pump and inspect the reaction shaft, input shaft and
input shaft seals.
Are any of the parts worn or damaged?
All
Yes ® Repair or replace the parts as necessary. Replace the Torque
Converter.
Perform the Transmission Verification Test - Ver 1.
No ® Replace the Torque Converter.
Perform the Transmission Verification Test - Ver 1.
16 At this time, the conditions required to set the DTC are not present.
Note: Use the Freeze Frame Data to help duplicate the conditions that set
the DTC. Pay particular attention to the DTC set conditions, such as, VSS,
MAP, ECT, and Load.
Note: Visually inspect the related wiring harness. Look for any chafed,
pierced, pinched, or partially broken wires.
Note: Visually inspect the related wiring harness connectors. Look for
broken, bent, pushed out, or corroded terminals.
Note: Refer to any technical service bulletins that may apply.
Were any problems found?
All
Yes ® Repair as necessary.
Perform the Transmission DTC Verification test.
NO- TEST COMPLETE
Test Complete.
P1740-TCC OR O/D SOLENOID PERFORMANCE
When Monitored and Set Condition:
P1740-TCC OR O/D SOLENOID PERFORMANCE
When Monitored: The Torque Converter Clutch (TCC) and Overdrive Clutch (O/D) will be
tested each time the PCM requests TCC engagement in 3rd gear and O/D.
Set Condition: The DTC will set if the expected engine rpm to output shaft speed rpm
ratio is not achieved during TCC and/or O/D engagement. This indicates malfunctioning
torque converter or overdrive clutch.
POSSIBLE CAUSES
TORQUE CONVERTER
INTERMITTENT 3-4 SOLENOID
INTERNAL TRANSMISSION PROBLEM - OD CLUTCH/SEALS OR VALVE BODY CONTAMINATION
OIL BURNT OR OIL PAN HAS EXCESSIVE DEBRIS
COOLER FLOW RESTRICTED
OIL PUMP/SHAFT
OIL PUMP/SHAFT
TRANSMISSION FLUID LEVEL AND CONDITION
INTERMITTENT GOV PRESSURE SENSOR SIGNAL
INTERMITTENT TCC SOLENOID
INTERNAL PROBLEM OR TCC SOLENOID
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRB, read DTCs.
Is the Specific Good Trip Counter for P-1740 displayed and equal to 0?
All
Yes ® Go To 2
No ® Go To 16
TEST ACTION APPLICABILITY
2 The following vehicle states (conditions) must be met before Test Driving Vehicle.
Transmission Control Relay DTCs must not be present.
Misfire DTCs must not be present.
P0753-TRANSMISSION 3-4 SHIFT SOLENOID/TRANSMISSION RELAY CIRCUIT
DTC must not be present.
P0743-TORQUE CONVERTER CLUTCH SOLENOID DTC must not be present.
Throttle Position Sensor DTCs must not be present.
P1899-P/N SWITCH STUCK DTC must not be present.
Repair all Engine RPM DTCs.
P0340-NO CAM SIGNAL AT PCM DTC must not be present.
Output Shaft Speed DTCs must not be present.
The fuel level must not be low.
Move the Transfer Case Lever out of Low Range.
Disengage the PTO.
Warm the transmission temperature to above 0°C (32°F).
The transmission fluid level must be full and must not contain any debris.
With the DRB, build a custom display to monitor Engine RPM, Output Shaft Speed,
TCC Solenoid, O/D Solenoid, Gear Status and Throttle Position.
Note: The display will be used to monitor the operation of the components.
Set the Overdrive to the off position.
Test drive the vehicle. Attain a steady speed of 89 kmh (55 MPH) with a minimum of
1.15 volts throttle opening for 20 seconds. Ensure the transmission shifts to 3rd gear
and the torque converter clutch is engaged.
Monitor shift patterns while the vehicle is upshifting to vehicle speed.
Is the engine rpm within 60 rpm of the Output Shaft Speed rpm?
All
Yes ® Go To 3
No ® Go To 8
3 Test drive the vehicle.
Attain a steady speed of 89 kmh (55 MPH), ensuring the TCC is engaged, then
engage the Overdrive.
Note: Output Shaft Speed x 0.69 = Expected Engine RPM
Did the engine rpm drop to 0.69 of the Output Shaft Speed?
All
Yes ® Go To 4
No ® Go To 9
4 Turn the ignition off.
Connect a 0 - 2068 KPa (0 - 300 PSI) pressure gauge to the Overdrive Clutch test port.
Connect another 0 - 2068 KPa (0 - 300 PSI) pressure gauge to the Governor Pressure
test port.
Start the engine and allow the transmission temperature to rise to normal operating
temperature.
Caution: Apply the parking brake.
Place the gear selector in Drive.
While observing the pressure gauges, select 4th gear from Gov and 3-4 Shift Valve
Test with the DRB.
Note: The governor pressure should rise to above 138 KPa (20 PSI). Shortly
after this, the O/D pressure should rise to above 276 KPa (40 PSI).
Did the pressure act as described?
All
Yes ® Go To 5
No ® Go To 7
TEST ACTION APPLICABILITY
5 Turn the ignition off.
Remove the transmission oil pan and inspect for excessive debris and burnt oil.
Is the oil burnt or does the transmission oil pan contain excessive debris?
All
Yes ® Repair the internal transmission problem in accordance with the
Service Information.
Perform the Transmission DTC Verification test.
No ® Go To 6
6 The vehicle must be driven (road load) to set this code. Drive the vehicle 4 times from
0 to 89 kmh (0 to 55 MPH) with a constant 20 % throttle position through all gears.
Stop the vehicle, shut the engine off and then repeat the procedure.
At this time, the conditions required to set the DTC are not present.
Note: Use the Freeze Frame Data to help duplicate the conditions that set
the DTC. Pay particular attention to the DTC set conditions, such as, VSS,
MAP, ECT, and Load.
Note: Visually inspect the related wiring harness. Look for any chafed,
pierced, pinched, or partially broken wires.
Note: Visually inspect the related wiring harness connectors. Look for
broken, bent, pushed out, or corroded terminals.
Note: Refer to any technical service bulletins that may apply.
Were any problems found?
All
Yes ® Repair as necessary. Pay particular attention to contamination in
the 3-4 Shift Solenoid.
Perform the Transmission DTC Verification test.
No ® Test Complete.
7 Turn the ignition off.
Replace the 3-4 Shift Solenoid (part of the Transmission Solenoid Assembly) in
accordance with the Service Information.
Connect a 0 - 2068 KPa (0 - 300 PSI) pressure gauge to the Overdrive Clutch test port.
Connect another 0 - 2068 KPa (0 - 300 PSI) pressure gauge to the Governor Pressure
test port.
Start the engine and allow the transmission temperature to reach normal operating
temperature.
Caution: Apply the parking brake.
Place the gear selector in Drive.
While observing the pressure gauges, actuate the 3-4 Shift Solenoid with the DRB.
Note: The governor pressure should rise to above 138 KPa (20 PSI). Shortly
after this, the O/D pressure should rise to above 276 KPa (40 PSI).
Did the pressure act as described?
All
Yes ® Test Complete.
No ® Overhaul the transmission in accordance with the Service Information.
Pay extra attention to Seals and Clutches related to the
OD Clutch and check for Valve Body contamination.
Perform the Transmission DTC Verification test.
8 Start the engine.
Allow the transmission to reach normal operating temperature.
Check the transmission fluid level and condition.
Is the fluid level correct and the fluid condition OK?
All
Yes ® Go To 9
No ® Repair as necessary.
TEST ACTION APPLICABILITY
9 Start the engine.
With the DRB, perform the TCC System Test.
Did the engine stall?
All
Yes ® Go To 10
No ® Go To 14
10 Start the engine.
Perform the Gov and 3-4 Shift Valve System Test. Select 4th gear.
Did the engine stall?
All
Yes ® Go To 11
No ® Go To 12
11 Turn the ignition off.
Replace the TCC Solenoid (part of the Transmission Solenoid Assembly) in accordance
with the Service Information.
Perform the Gov and 3-4 Shift Valve System Test.
Wtih the DRB, select 4th gear.
Did the engine stall?
All
Yes ® Repair the internal transmission problem in accordance with the
Service Information. Check for blocked passage(s).
Perform Transmission DTC Verification Test
No-Test Complete
Test Complete.
12 Turn the ignition off.
Remove the transmission oil pump and inspect the reaction shaft, input shaft and
input shaft seals.
Are any of the parts worn or damaged?
All
Yes ® Repair or replace the parts as necessary. Replace the Torque
Converter.
Perform the Transmission Verification Test - Ver 1.
No ® Go To 13
13 At this time, the conditions required to set the DTC are not present.
Note: Use the Freeze Frame Data to help duplicate the conditions that set
the DTC. Pay particular attention to the DTC set conditions, such as, VSS,
MAP, ECT, and Load.
Note: Visually inspect the related wiring harness. Look for any chafed,
pierced, pinched, or partially broken wires.
Note: Visually inspect the related wiring harness connectors. Look for
broken, bent, pushed out, or corroded terminals.
Note: Refer to any technical service bulletins that may apply.
Were any problems found?
All
Yes ® Repair as necessary.
Perform Transmission DTC Verification Test
NO- TEST COMPLETE
Test Complete.
TEST ACTION APPLICABILITY
14 Turn the ignition off.
Connect a pressure gauge to the transmission cooler out port with a 9T9 connector.
Start the engine.
With the DRB, perform TCC System Test.
Did the cooler out pressure increase when the TCC was actuated?
All
Yes ® Go To 15
No ® Repair the valve body in accordance with the Service Information.
Check for blockages or leaks in the TCC hydraulic circuit.
Perform the Transmission Verification Test - Ver 1.
15 Turn the ignition off.
Remove the transmission oil pump and inspect the reaction shaft, input shaft and
input shaft seals.
Are any of the parts worn or damaged?
All
Yes ® Repair or replace the parts as necessary. Replace the Torque
Converter.
Perform the Transmission Verification Test - Ver 1.
No ® Replace the Torque Converter.
Perform the Transmission Verification Test - Ver 1.
16 At this time, the conditions required to set the DTC are not present.
Note: Use the Freeze Frame Data to help duplicate the conditions that set
the DTC. Pay particular attention to the DTC set conditions, such as, VSS,
MAP, ECT, and Load.
Note: Visually inspect the related wiring harness. Look for any chafed,
pierced, pinched, or partially broken wires.
Note: Visually inspect the related wiring harness connectors. Look for
broken, bent, pushed out, or corroded terminals.
Note: Refer to any technical service bulletins that may apply.
Were any problems found?
All
Yes ® Repair as necessary.
Perform the Transmission DTC Verification test.
NO- TEST COMPLETE
Test Complete.