Scheme 68
Circuit Description
The transmission control module (TCM) provides voltage to the pressure control solenoid, the shift solenoids, and the TCC PWM solenoid through 2 separate solid-state devices called High Side Drivers, called HSD1 and HSD2. HSD1 provides electrical power to the pressure control solenoid. HSD2 provides power to the shift solenoids. A normal function of the TCM is to run tests on each driver to ensure that it is functioning properly.
When the TCM detects a short to voltage on HSD2, then DTC P1834 sets. DTC P1834 is a type B DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC
DTC P1834 Torque Converter Clutch (TCC)/Shift Solenoid (SS) Control Circuit High Voltage
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
The TCM detects greater than 6.4 volts at the HSD2 terminal prior to commanding the HSD2 ON.
Action Taken When the DTC Sets
- The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive drive trip in which the Conditions for Setting the DTC are met.
- The TCM turns off power to all solenoids.
- The transmission will operate in fifth gear if the vehicle has successfully completed a 1-2 upshift in the current ignition cycle. If the vehicle has not completed a 1-2 upshift in the current ignition cycle, the transmission will operate in fourth gear.
- The TCM commands maximum line pressure.
- The TCM freezes transmission adaptive functions.
- The TCC is disabled.
- The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
- The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
- The TCM stores DTC P1834 in TCM history.
Conditions for Clearing the MIL/DTC
- The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
- A scan tool can clear the MIL/DTC.
- The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission related diagnostic fault occurring.
- The TCM cancels the default actions when the ignition is OFF long enough in order to power down the TCM.
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information | |
| 2 | Install a scan tool. Turn ON the ignition with the engine OFF. IMPORTANT: Before clearing the DTC, use the scan tool in order to record the ECM Freeze Frame and the TCM Failure Records. Using the Clear Info function erases the Freeze Frame and Failure Records from the ECM and the TCM. Using the Clear Info function erases stored DTCs in both the ECM and TCM. Record the DTC Freeze Frame and Failure Records. Clear the DTC. Turn OFF the ignition for at least 30 seconds. Turn ON the ignition, with the engine OFF. Did DTC P1834 reset? | Go to Step 3 | Go to Intermittent Conditions in Engine Controls - 3.6L or Intermittent Conditions in Engine Controls - 4.6L | |
| 3 | Turn OFF the ignition. Disconnect the TCM. Turn ON the ignition with the engine OFF. Measure the voltage at the solenoid supply voltage circuit of the TCM harness connector. Refer to Automatic Transmission Related Connector End Views (5L40-E) or Automatic Transmission Related Connector End Views (5L50-E) and Circuit Testing in Wiring Systems. Is the voltage greater than the specified value? | 6.4 volts | Go to Step 4 | Go to Step 5 |
| 4 | Repair the short to voltage on the solenoid supply voltage circuit. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | Go to Step 6 | ||
| 5 | Replace the TCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Is the action complete? | Go to Step 6 | ||
| 6 | Perform the following procedure in order to verify the repair: Select DTC. Select Clear Info. Turn ON the ignition, with the engine OFF. Select Specific DTC. Enter DTC P1834. Has the test run and passed? | Go to Step 7 | Go to Step 2 | |
| 7 | With the scan tool, observe the stored information, capture info and DTC info. Does the scan tool display any DTCs that you have not diagnosed? | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | System OK |
| IMPORTANT |
|---|
| Before clearing the DTC, use the scan tool in order to record the ECM Freeze Frame and the TCM Failure Records. Using the Clear Info function erases the Freeze Frame and Failure Records from the ECM and the TCM. Using the Clear Info function erases stored DTCs in both the ECM and TCM. |
DTC P1834
The TAP Shift system allows the driver to manually shift gears by using the Upshift and Downshift positions located on the automatic transmission shift Lever. Pushing the lever to the Upshift position will command an upshift and pushing the lever to the Downshift position will command a downshift. The TAP Shift system is activated when the gear selector is in the manual, M, position and is deactivated in all other positions.
If the transmission control module (TCM) detects TAP enable switch Active and the IMS does not indicate D5, DTC P1876 sets. DTC P1876 is a type C DTC.
This diagnostic procedure supports the following DTC
DTC P1876 Up and Down Shift Switch Performance - Range Switch Not in D3
- No TAP system DTCs P0815, P0816 or P0826.
- No IMS range DTCs P1815, P1820, P1822, P1823, P1825 or P1826.
- The engine run time is greater than 5 seconds.
- No CAN errors present.
The TCM detects the TAP enable switch is Active and the IMS range is not D5 for 5 seconds.
- The TCM does not request the ECM to illuminate the malfunction indicator lamp (MIL).
- The TCM disables TAP Shift operation.
- The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information a Failure Record.
- The TCM stores DTC P1876 in TCM history.
Conditions for Clearing the DTC
- A scan tool can clear the DTC.
- The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non emission related diagnostic fault occurring.
- The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM.
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information | |
| 2 | Install a scan tool. Turn ON the ignition, with the engine OFF. IMPORTANT: Before clearing the DTC, use the scan tool in order to record the Failure Records. Using the Clear DTC Information function erases the Failure Records from the TCM. Record the DTC Failure Records. Clear the DTC. Start the engine. Move the A/T Shift Lever to the Manual position. Select IMS on the scan tool. Does the scan tool IMS parameter display Drive 5? | Go to Intermittent Conditions in Engine Controls - 3.6L or Intermittent Conditions in Engine Controls - 4.6L | Go to Step 3 | |
| 3 | Select IMS A/B/C/P on the scan tool. Place the gear select lever in the Manual position. Does the scan tool IMS A/B/C/P display indicate the specified value for each range? | HI/HI/HI/HI | Go to Step 14 | Go to Step 4 |
| 4 | Inspect the transmission linkage from the range selector to the manual shift shaft for proper adjustment. Adjust the linkage as necessary. Refer to Manual Shaft Shift Position Switch Replacement . Did the linkage require adjustment? | Go to Step 19 | Go to Step 5 | |
| 5 | Turn OFF the ignition. Disconnect the AT inline 20-way connector. Additional DTCs may set. Turn ON the ignition, with the engine OFF. Select IMS A/B/C/P on the scan tool. Does the scan tool IMS A/B/C/P display all HI? | Go to Step 6 | Go to Step 10 | |
| 6 | Turn OFF the ignition. Install the J 45681 jumper harness on the TCM side of the AT inline 20-way connector. See Special Tools . Turn ON the ignition, with the engine OFF. Using the DMM and the J 35616 GM terminal test kit, measure the voltage at the Transmission Range (TR) signal A circuit of the J 45681 . See Special Tools . Refer to Automatic Transmission Inline 20-Way Connector End View (5L40-E) or Automatic Transmission Inline 20-Way Connector End View (5L50-E) . Measure the voltage at the TR signal B of the J 45681 . See Special Tools . Measure the voltage at the TR signal C of the J 45681 . See Special Tools . Measure the voltage at the TR signal P of the J 45681 . See Special Tools . Did you measure ignition voltage at all four terminals? | Go to Step 7 | Go to Step 11 | |
| 7 | Install a fused jumper wire from the TR signal A circuit of the J 45681 to ground while monitoring the scan tool IMS A/B/C/P display. See Special Tools . Refer to Automatic Transmission Inline 20-Way Connector End View (5L40-E) or Automatic Transmission Inline 20-Way Connector End View (5L50-E) . When the TR signal A circuit is grounded, do any other circuits indicate LOW? | Go to Step 12 | Go to Step 8 | |
| 8 | Install a fused jumper wire from the TR signal B circuit of the J 45681 to ground while monitoring the scan tool IMS A/B/C/P display. See Special Tools . Refer to Automatic Transmission Inline 20-Way Connector End View (5L40-E) or Automatic Transmission Inline 20-Way Connector End View (5L50-E) . When the TR signal B circuit is grounded, do any other circuits indicate LOW? | Go to Step 12 | Go to Step 9 | |
| 9 | Install a fused jumper wire from the TR signal C circuit of the J 45681 to ground while monitoring the scan tool IMS A/B/C/P display. See Special Tools . Refer to Automatic Transmission Inline 20-Way Connector End View (5L40-E) or Automatic Transmission Inline 20-Way Connector End View (5L50-E) . When the TR signal C circuit is grounded, do any other circuits indicate LOW? | Go to Step 12 | Go to Step 13 | |
| 10 | Test the TR signal circuits of the transmission manual shift shaft switch assembly that did not indicate HI for a short to ground between the TCM connector and the AT inline 20-way connector. Refer to Testing for Short to Ground and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 19 | Go to Step 18 | |
| 11 | Test the TR signal circuits of the transmission manual shift shaft switch assembly that did not indicate ignition voltage for an open between the TCM connector and the AT inline 20-way connector. Refer to Testing for Continuity and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 19 | Go to Step 18 | |
| 12 | Test the affected signal circuits of the transmission manual shift shaft switch assembly for a shorted together condition between the TCM connector and the AT inline 20-way connector. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 19 | Go to Step 18 | |
| 13 | Test the TR signal circuits of the transmission manual shift shaft switch assembly for an open or shorted condition between the AT inline 20-way connector and the switch. Refer to Testing for Continuity in Wiring Systems. Did you find and correct the condition? | Go to Step 16 | Go to Step 17 | |
| 14 | Test the ground circuit of the transmission manual shift shaft switch assembly for an open between the AT inline 20-way connector and the chassis. Refer to Testing for Continuity and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 19 | Go to Step 15 | |
| 15 | Test the ground circuit of the transmission manual shift shaft switch assembly for an open between the AT inline 20-way connector and the switch. Refer to Testing for Continuity in Wiring Systems. Did you find and correct the condition? | Go to Step 16 | Go to Step 17 | |
| 16 | Replace the automatic transmission wiring harness assembly. Refer to Transmission Internal Electrical Harness Replacement . Did you complete the replacement? | Go to Step 19 | ||
| 17 | Replace the transmission manual shift shaft switch assembly. Refer to Manual Shaft Shift Position Switch Replacement . Is the action complete? | Go to Step 19 | ||
| 18 | Replace the TCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Is the action complete? | Go to Step 19 | ||
| 19 | Perform the following procedure in order to verify the repair: Select DTC. Select Clear Info. Start the engine. Place the A/T Shift Lever in the Manual position. Select Specific DTC. Enter DTC P1876. Has the test run and passed? | Go to Step 20 | Go to Step 2 | |
| 20 | With the scan tool, observe the stored information, capture info and DTC info. Does the scan tool display any DTCs that you have not diagnosed? | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | System OK |
| IMPORTANT |
|---|
| Before clearing the DTC, use the scan tool in order to record the Failure Records. Using the Clear DTC Information function erases the Failure Records from the TCM. |
DTC P1876
To improve shift feel, the transmission control module (TCM) may request that the engine control module (ECM) reduce engine torque during shift events. When such a request is received, the ECM responds by retarding the base ignition timing and notifying the TCM that the request has succeeded. If the ECM is unable to comply with the request, the ECM sends the TCM a message that the request has failed.
The torque reduction request is sent to the ECM through a communication network called the controller area network (CAN). Two circuits are used to communicate CAN data between the ECM and TCM. A fault in the CAN will not cause DTC P2544 to set by itself. If a CAN fault occurs, other DTCs will set before DTC P2544.
When the TCM receives a torque reduction failure message from the ECM, then DTC P2544 will set. DTC P2544 is a type B DTC.
This diagnostic procedure supports the following DTC
DTC P2544 Transmission Torque Request Circuit
- The engine run time is greater than 5 seconds.
- No other CAN errors are present.
The ECM notifies the TCM that a torque reduction request has failed for 2 seconds.
- The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
- The TCM commands maximum line pressure.
- The TCM freezes transmission adaptive functions.
- The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
- The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
- The TCM stores DTC P2544 in TCM history.
- The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
- A scan tool can clear the DTC.
- The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non emission related diagnostic fault occurring.
- The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM.
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information | |
| 2 | Install a scan tool. Turn ON the ignition with the engine OFF. IMPORTANT: Before clearing the DTC, use the scan tool in order to record the ECM Freeze Frame and the TCM Failure Records. Using the Clear Info function erases the Freeze Frame and Failure Records from the ECM and the TCM. Using the Clear Info function erases stored DTCs in both the ECM and TCM. Record the DTC Failure Records. Did you record any ECM Failure Records? | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | Go to Step 3 | |
| 3 | Clear the DTC. Turn the ignition OFF for at least 30 seconds. Start, and allow the engine to idle, then drive the vehicle. Did DTC P2544 reset? | Go to Step 4 | Go to Intermittent Conditions in Engine Controls - 3.6L or Intermittent Conditions in Engine Controls - 4.6L | |
| 4 | Did any other DTCs set? | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | Go to Step 5 | |
| 5 | Replace the TCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Is the action complete? | Go to Step 6 | ||
| 6 | Perform the following operation to verify the repair: Select DTC on the scan tool. Select Clear Info. Start, and allow the engine to idle. Select Specific DTC. Enter DTC P2544. Has the test run and passed? | Go to Step 7 | Go to Step 2 | |
| 7 | With the scan tool, observe the stored information, capture info and DTC info. Does the scan tool display any DTCs that you have not diagnosed? | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | System OK |
| IMPORTANT |
|---|
| Before clearing the DTC, use the scan tool in order to record the ECM Freeze Frame and the TCM Failure Records. Using the Clear Info function erases the Freeze Frame and Failure Records from the ECM and the TCM. Using the Clear Info function erases stored DTCs in both the ECM and TCM. |
DTC P2544
Engine torque information is sent to the transmission control module (TCM) by the engine control module (ECM) through a communication network called the controller area network (CAN). Two circuits are used to communicate CAN data between the ECM and TCM. A fault in the CAN will not cause DTC P2637 to set by itself. If a CAN fault occurs, other DTCs will set before DTC P2637.
When the ECM sends the TCM an engine torque signal that is invalid, DTC P2637 will set. DTC P2637 is a type B DTC.
This diagnostic procedure supports the following DTC
DTC P2637 Transmission Torque Delivered Circuit
- The engine run time is greater than 5 seconds.
- No other CAN errors are present.
The TCM receives an invalid engine torque value for 2 seconds.
- The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
- The TCM commands maximum line pressure.
- The TCM freezes transmission adaptive functions.
- The TCM inhibits autograde braking and shift stabilization.
- The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
- The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
- The TCM stores DTC P2637 in TCM history.
- The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
- A scan tool can clear the DTC.
- The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non emission related diagnostic fault occurring.
- The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM.
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information | |
| 2 | Install a scan tool. Turn ON the ignition with the engine OFF. IMPORTANT: Before clearing the DTC, use the scan tool in order to record the ECM Freeze Frame and the TCM Failure Records. Using the Clear Info function erases the Freeze Frame and Failure Records from the ECM and the TCM. Using the Clear Info function erases stored DTCs in both the ECM and TCM. Record the DTC Failure Records. Did you record any ECM Failure Records? | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | Go to Step 3 | |
| 3 | Clear the DTC. Turn the ignition OFF for at least 30 seconds. Start, and allow the engine to idle, then drive the vehicle. Did DTC P2637 reset? | Go to Step 4 | Go to Intermittent Conditions in Engine Controls - 3.6L or Intermittent Conditions in Engine Controls - 4.6L | |
| 4 | Did any other DTCs set? | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | Go to Step 5 | |
| 5 | Replace the TCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Is the action complete? | Go to Step 6 | ||
| 6 | Perform the following operation to verify the repair: Select DTC on the scan tool. Select Clear Info. Start, and idle the engine. Select Specific DTC. Enter DTC P2637. Has the test run and passed? | Go to Step 7 | Go to Step 2 | |
| 7 | With the scan tool, observe the stored information, capture info and DTC info. Does the scan tool display any DTCs that you have not diagnosed? | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | System OK |
| IMPORTANT |
|---|
| Before clearing the DTC, use the scan tool in order to record the ECM Freeze Frame and the TCM Failure Records. Using the Clear Info function erases the Freeze Frame and Failure Records from the ECM and the TCM. Using the Clear Info function erases stored DTCs in both the ECM and TCM. |
DTC P2637
Scheme 69
The transmission control module (TCM) provides voltage to the torque converter clutch pulse width modulated (TCC PWM) solenoid valve through high side driver 2 (HSD2). The TCM controls the ON and OFF time of the solenoid by providing a ground through the output driver module (ODM). The TCM uses a PWM duty cycle, in order to control application and release of the TCC. When the solenoid is commanded OFF, the TCM senses high voltage. When the solenoid is commanded ON, the TCM senses low voltage.
When the TCM detects a short to voltage in the TCC PWM solenoid valve circuit, then DTC P2763 sets. DTC P2763 is a type B DTC.
This diagnostic procedure supports the following DTC
DTC P2763 Torque Converter Clutch (TCC) Pressure Control (PC) Solenoid Control Circuit High Voltage
- The engine run time is greater than 5 seconds.
- HSD2 is commanded ON.
DTC P2763 sets when the TCM detects an short to voltage in the TCC PWM solenoid valve circuit when the PWM duty cycle is 45 percent or greater for 4.3 seconds.
- The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive drive trip in which the Conditions for Setting the DTC are met.
- The TCM inhibits fifth gear if the transmission is in Hot Mode.
- The TCM inhibits the TCC.
- The TCM freezes transmission adaptive functions.
- The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
- The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
- The TCM stores DTC P2763 in TCM history.
- The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
- A scan tool can clear the MIL/DTC.
- The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission related diagnostic fault occurring.
- The TCM cancels the default actions when the ignition is OFF long enough in order to power down the TCM.
Test Description
The number below refers to the step number on the diagnostic table.
- 2: Listen for a soft rattling sound when the solenoid energizes. Use a stethoscope if necessary.
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information | |
| 2 | Install a scan tool. Turn ON the ignition with the engine OFF. IMPORTANT: Before clearing the DTC, use the scan tool in order to record the ECM Freeze Frame and the TCM Failure Records. Using the Clear Info function erases the Freeze Frame and Failure Records from the ECM and the TCM. Using the Clear Info function erases stored DTCs in both the ECM and TCM. Record the DTC Freeze Frame and Failure Records. Clear the DTC. Use the scan tool in order to command the TCC PWM solenoid ON. Does the solenoid operate? | Go to Step 8 | Go to Step 3 | |
| 3 | Turn OFF the ignition. Disconnect the AT 20-way inline harness connector. Install the J 45681 jumper harness to the TCM side of the 20-way connector. See Special Tools . Turn ON the ignition with the engine OFF. With the test lamp connected to ground, probe the solenoid supply voltage circuit of the J 45681 . See Special Tools . Does the test lamp illuminate? | Go to Step 4 | Go to Step 6 | |
| 4 | Turn OFF the ignition. Install the J 45681 to the transmission side of the 20-way connector. See Special Tools . Using the DMM, measure the resistance between the solenoid supply voltage circuit and the TCC PWM solenoid valve control circuit of the J 45681 . See Special Tools . Refer to Component Resistance . Is the resistance within the specified range? | 10.0-13.6 ohm | Go to Step 5 | Go to Step 7 |
| 5 | Disconnect the TCM. Test the TCC PWM solenoid valve control circuit and the solenoid supply voltage for an open or a short to voltage. Refer to Testing for a Short to Voltage in Wiring Systems. Did you find and correct the condition? | Go to Step 11 | Go to Step 8 | |
| 6 | Turn OFF the ignition. Disconnect the TCM. Test the solenoid supply voltage circuit and the solenoid valve control circuit from the TCM to the TCC PWM solenoid valve for an open circuit. Refer to Testing for Continuity in Wiring Systems. Did you find a condition? | Go to Step 11 | Go to Step 8 | |
| 7 | Remove the transmission oil pan. Test the solenoid supply voltage circuit from the 20-way connector to the TCC PWM solenoid valve connector for an open or short to voltage. Refer to Testing for a Short to Voltage in Wiring Systems. Did you find a condition? | Go to Step 9 | Go to Step 10 | |
| 8 | Replace the TCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Is the action complete? | Go to Step 11 | ||
| 9 | Replace the AT internal transmission wiring harness. Refer to Transmission Internal Electrical Harness Replacement . Is the action complete? | Go to Step 11 | ||
| 10 | Replace the TCC PWM solenoid valve. Refer to Torque Converter Clutch (TCC) Solenoid Replacement . Is the action complete? | Go to Step 11 | ||
| 11 | Perform the following procedure in order to verify the repair: Select DTC. Select Clear Info. Start the engine. Drive the vehicle with the TCC Duty Cycle above 40 percent for 5 seconds. Select Specific DTC. Enter DTC P2763. Has the test run and passed? | Go to Step 12 | Go to Step 2 | |
| 12 | With the scan tool, observe the stored information, capture info and DTC info. Does the scan tool display any DTCs that you have not diagnosed? | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | System OK |
| IMPORTANT |
|---|
| Before clearing the DTC, use the scan tool in order to record the ECM Freeze Frame and the TCM Failure Records. Using the Clear Info function erases the Freeze Frame and Failure Records from the ECM and the TCM. Using the Clear Info function erases stored DTCs in both the ECM and TCM. |
DTC P2763
The transmission control module (TCM) provides voltage to the torque converter clutch pulse width modulated (TCC PWM) solenoid valve through high side driver 2 (HSD2). The TCM controls the ON and OFF time of the solenoid by providing a ground through the output driver module (ODM). The TCM uses a PWM duty cycle, in order to control application and release of the TCC. When the solenoid is commanded OFF, the TCM senses high voltage. When the solenoid is commanded ON, the TCM senses low voltage.
When the TCM detects a continuous open or short to ground in the TCC PWM Solenoid valve circuit, then DTC P2764 sets. DTC P2764 is a type B DTC.
This diagnostic procedure supports the following DTC
DTC P2764 Torque Converter Clutch (TCC) Pressure Control (PC) Solenoid Control Circuit Low Voltage
- The engine run time is greater than 5 seconds.
- HSD2 is commanded ON.
DTC P2764 sets when either of the following conditions occur for 4.3 seconds
- The TCM detects an open in the TCC PWM solenoid valve circuit when the PWM duty cycle is greater than 20 percent.
- The TCM detects a short to ground in the TCC PWM solenoid valve circuit when the PWM duty cycle is greater than 20 percent but less than 50 percent.
- The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the second consecutive drive trip in which the Conditions for Setting the DTC are met.
- The TCM turns off power to all solenoids.
- The transmission will operate in fifth gear if the vehicle has successfully completed a 1-2 upshift in the current ignition cycle. If the vehicle has not completed a 1-2 upshift in the current ignition cycle, the transmission will operate in fourth gear.
- The TCM commands maximum line pressure.
- The TCM freezes transmission adaptive functions.
- The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
- The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
- The TCM stores DTC P2764 in TCM history.
- The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
- A scan tool can clear the MIL/DTC.
- The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission related diagnostic fault occurring.
- The TCM cancels the default actions when the ignition is OFF long enough in order to power down the TCM.
The number below refers to the step number on the diagnostic table.
- 2: Listen for a soft rattling sound when the solenoid energizes. Use a stethoscope if necessary.
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| 1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information | |
| 2 | Install a scan tool. Turn ON the ignition with the engine OFF. IMPORTANT: Before clearing the DTC, use the scan tool in order to record the ECM Freeze Frame and the TCM Failure Records. Using the Clear Info function erases the Freeze Frame and Failure Records from the ECM and the TCM. Using the Clear Info function erases stored DTCs in both the ECM and TCM. Record the DTC Freeze Frame and Failure Records. Clear the DTC. Use the scan tool in order to command the TCC PWM solenoid ON. Does the solenoid operate? | Go to Step 9 | Go to Step 3 | |
| 3 | Turn OFF the ignition. Disconnect the AT 20-way inline harness connector. Install the J 45681 jumper harness to the TCM side of the 20-way connector. See Special Tools . Turn ON the ignition with the engine OFF. With the test lamp connected to ground, probe the solenoid supply voltage circuit of J 45681 . See Special Tools . Does the test lamp illuminate? | Go to Step 4 | Go to Step 7 | |
| 4 | Turn OFF the ignition. Install the J 45681 to the transmission side of the 20-way connector. See Special Tools . Using the DMM, measure the resistance between the solenoid supply voltage circuit and the TCC PWM solenoid valve control circuit of the J 45681 . See Special Tools . Refer to Component Resistance . Is the resistance within the specified range? | 10.0-13.6ohm | Go to Step 5 | Go to Step 8 |
| 5 | Using the DMM, measure the resistance between the solenoid supply voltage circuit of the J 45681 and ground. See Special Tools . Is the resistance greater than the specified value? | 50K ohm | Go to Step 6 | Go to Step 8 |
| 6 | Disconnect the TCM. Test the TCC PWM solenoid valve control circuit for an open or short to ground. Refer to Testing for Continuity and Testing for Short to Ground in Wiring Systems.Did you find and correct the condition? | Go to Step 12 | Go to Step 9 | |
| 7 | Turn OFF the ignition. Disconnect the TCM. Test the solenoid supply voltage circuit and the solenoid valve control circuit from the TCM to the TCC PWM solenoid valve for an open circuit. Refer to Testing for Continuity in Wiring Systems. Did you find and correct the condition? | Go to Step 12 | Go to Step 9 | |
| 8 | Remove the transmission oil pan. Test the solenoid supply voltage circuit and the solenoid valve control circuit from the 20-way connector to the TCC PWM solenoid valve connector for an open or short to ground. Refer to Testing for Continuity and Testing for Short to Ground in Wiring Systems.Did you find a condition? | Go to Step 10 | Go to Step 11 | |
| 9 | Replace the TCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Is the action complete? | Go to Step 12 | ||
| 10 | Replace the AT internal transmission wiring harness. Refer to Transmission Internal Electrical Harness Replacement . Is the action complete? | Go to Step 12 | ||
| 11 | Replace the TCC PWM solenoid valve. Refer to Torque Converter Clutch (TCC) Solenoid Replacement . Is the action complete? | Go to Step 12 | ||
| 12 | Perform the following procedure in order to verify the repair: Select DTC. Select Clear Info. Start the engine. Drive the vehicle with the TCC Duty Cycle above 36% for 5 seconds. Select Specific DTC. Enter DTC P2764. Has the test run and passed? | Go to Step 13 | Go to Step 2 | |
| 13 | With the scan tool, observe the stored information, capture info and DTC info. Does the scan tool display any DTCs that you have not diagnosed? | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | System OK |
| IMPORTANT |
|---|
| Before clearing the DTC, use the scan tool in order to record the ECM Freeze Frame and the TCM Failure Records. Using the Clear Info function erases the Freeze Frame and Failure Records from the ECM and the TCM. Using the Clear Info function erases stored DTCs in both the ECM and TCM. |
DTC P2764
See also:
• Diagnostic System Check - Vehicle
• Intermittent Conditions
• Intermittent Conditions
• Automatic Transmission Related Connector End Views (5L40-E)
• Circuit Testing
• Wiring Repairs
• Control Module References
• Diagnostic Trouble Code (DTC) List - Vehicle
• Manual Shaft Shift Position Switch Replacement
• Special Tools
• Automatic Transmission Inline 20-Way Connector End View (5L40-E)
• Testing for Short to Ground
• Testing for Continuity
• Component Resistance
• Testing for a Short to Voltage