Automatic Transaxle - 4t65-e - DTC p1823 to DTC p2764 Buick LaCrosse I

Scheme 89

Circuit Description

The transmission internal mode switch (IMS) is a sliding contact switch attached to the selector detent inside the transmission side cover. The four inputs to the TCM indicate the position of the transmission range selector. The input voltage level at the TCM is high, B+, when the IMS is open and low when the switch is closed to ground. The four input parameters represented are Signals A, B, C and P - Parity. Refer to Transmission Internal Mode Switch Logic .

If the TCM detects that IMS Signal P is always low, then DTC P1823 sets. DTC P1823 is a type B DTC.

DTC Descriptor

This diagnostic procedure supports the following DTC

DTC P1823 Internal Mode Switch P Circuit Low Voltage

Conditions for Running the DTC

1. The engine speed is greater than 500 RPM for 5 seconds.
2. No engine torque malfunction.
3. The engine torque is 54-407 N.m (40-300 lb ft).
4. The IMS indicates PARK for 1 second or more.

Conditions for Setting the DTC

The IMS Signal P is continuously low this ignition cycle and the IMS indicates transitional position N-D4 for 8 seconds or more.

Action Taken When the DTC Sets

1. The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the consecutive trip in which the Conditions for Setting the DTC are met.
2. The TCM commands maximum line pressure.
3. The TCM commands an alternate coast shift pattern where downshifts occur at higher vehicle speeds while coasting.
4. The TCM freezes transmission adaptive functions.
5. The TCM assumes D4 for shifting.
6. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
7. The TCM stores DTC P1823 in TCM history during the consecutive trip in which the Conditions for Setting the DTC are met.

Conditions for Clearing the DTC

1. A scan tool can clear the DTC.
2. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
3. The TCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the TCM.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. 3: A LOW signal indicates a short to ground in the vehicle harness or the TCM.
2. 5: This step tests the internal transmission harness without the IMS connected.

DTC P1823 (3.6L)

Scheme 90

The transmission internal mode switch (IMS) is a sliding contact switch attached to the selector detent inside the transmission side cover. The four inputs to the PCM indicate the position of the transmission range selector. The input voltage level at the PCM is high, B+, when the IMS is open and low when the switch is closed to ground. The four input parameters represented are Signals A, B, C and P - Parity. Refer to Transmission Internal Mode Switch Logic .

If the PCM detects that IMS Signal P is always low, then DTC P1823 sets. DTC P1823 is a type B DTC.

This diagnostic procedure supports the following DTC

DTC P1823 Internal Mode Switch P Circuit Low Voltage

1. No MAP DTC P0107 or P0108.
2. The engine torque is 55-407 N.m (40-300 lb ft).
3. The engine speed is greater than 500 RPM for 5 seconds and not in fuel cut off.
4. The IMS indicates PARK for 2 seconds.

The IMS Signal P is continuously low this ignition cycle and the IMS indicates transitional position N-D4 for 60 seconds.

1. The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
2. The PCM commands maximum line pressure.
3. The PCM freezes transmission adaptive functions.
4. The PCM assumes D4 for shifting.
5. The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame and Failure Records.
6. The PCM stores DTC P1823 in PCM history during the second consecutive trip in which the Conditions for Setting the DTC are met.

Conditions for Clearing the MIL/DTC

1. The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes.
2. A scan tool can clear the MIL/DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
4. The PCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the PCM.

The numbers below refer to the step numbers on the diagnostic table.

1. 3: A LOW signal indicates a short to ground in the vehicle harness or the PCM.
2. 5: This step tests the internal transmission harness without the IMS connected.

DTC P1823 (3.8L)

The transmission internal mode switch (IMS) is a sliding contact switch attached to the selector detent inside the transmission side cover. The four inputs to the TCM indicate the position of the transmission range selector. The input voltage level at the TCM is high, B+, when the IMS is open and low when the switch is closed to ground. The four input parameters represented are Signals A, B, C and P - Parity. Refer to Transmission Internal Mode Switch Logic .

If the TCM detects an invalid transmission range with the engine running, then DTC P1825 sets. DTC P1825 is a type B DTC.

This diagnostic procedure supports the following DTC

DTC P1825 Internal Mode Switch - Invalid Range

1. The engine speed is greater than 500 RPM for 5 seconds.
2. The engine torque is greater than 50 N.m (37 lb ft).
3. The IMS indicates PARK or NEUTRAL for 1 second or more.

The TCM detects an invalid combination of IMS signals for 8 seconds or more.

1. The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the consecutive trip in which the Conditions for Setting the DTC are met.
2. The TCM commands maximum line pressure.
3. The TCM commands an alternate coast shift pattern where downshifts occur at higher vehicle speeds while coasting.
4. The TCM freezes transmission adaptive functions.
5. The TCM assumes D4 for shifting.
6. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
7. The TCM stores DTC P1825 in TCM history during the consecutive trip in which the Conditions for Setting the DTC are met.

1. A scan tool can clear the DTC.
2. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
3. The TCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the TCM.

The numbers below refer to the step numbers on the diagnostic table.

1. 3: HI values for all signals in all ranges indicates the ground circuit is OPEN.
2. 4: With the 20-way connector disconnected, all signals should indicate HI.
3. 6: If one circuit affects the other, this indicates a short between the two circuits.
4. 13: This step tests the internal transmission harness. If no fault is found in the harness, the fault will be in the switch.

DTC P1825 (3.6L)

The transmission internal mode switch (IMS) is a sliding contact switch attached to the selector detent inside the transmission side cover. The four inputs to the PCM indicate the position of the transmission range selector. The input voltage level at the PCM is high, B+, when the IMS is open and low when the switch is closed to ground. The four input parameters represented are Signals A, B, C and P - Parity. Refer to Transmission Internal Mode Switch Logic .

If the PCM detects an invalid transmission range with the engine running, then DTC P1825 sets. DTC P1825 is a type B DTC.

This diagnostic procedure supports the following DTC

DTC P1825 Internal Mode Switch - Invalid Range

The engine speed is at least 500 RPM for 5 seconds and not in fuel cut off.

The PCM detects an invalid combination of IMS signals for 60 seconds.

1. The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
2. The PCM commands maximum line pressure.
3. The PCM freezes transmission adaptive functions.
4. The PCM assumes D4 for shifting.
5. The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame and Failure Records.
6. The PCM stores DTC P1825 in PCM history during the second consecutive trip in which the Conditions for Setting the DTC are met.

1. The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes.
2. A scan tool can clear the MIL/DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
4. The PCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the PCM.

The numbers below refer to the step numbers on the diagnostic table.

1. 3: HI values for all signals in all ranges indicates the ground circuit is OPEN.
2. 4: With the 20-way connector disconnected, all signals should indicate HI.
3. 6: If one circuit affects the other, this indicates a short between the two circuits.
4. 13: This step tests the internal transmission harness. If no fault is found in the harness, the fault will be in the switch.

DTC P1825 (3.8L)

The transmission internal mode switch (IMS) is a sliding contact switch attached to the selector detent inside the transmission side cover. The 4 inputs to the TCM indicate the position of the transmission range selector. The input voltage level at the TCM is high, B+, when the IMS is open and low when the switch is closed to ground. The 4 input parameters represented are Signals A, B, C and P - Parity. Refer to Transmission Internal Mode Switch Logic .

If the TCM detects that IMS Signal C is high while the vehicle is being driven in a forward gear, then DTC P1826 sets. DTC P1826 is a type B DTC.

This diagnostic procedure supports the following DTC

DTC P1826 Internal Mode Switch C Circuit High Voltage

1. No OSS DTCs P0722 or P0723.
2. The engine speed is greater than 500 RPM for 5 seconds.
3. The IMS indicates PARK or NEUTRAL for 1 second or more.
4. Vehicle speed is 16 km/h (10 mph) or more.
5. Engine torque is 50 N.m (37 lb ft) or more.
6. DTC P1826 has not passed this key cycle.

The TCM detects IMS Signal C is high, while the gear ratio indicates first, second, third or fourth gear for 8 seconds or more.

1. The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL) during the consecutive trip in which the Conditions for Setting the DTC are met.
2. The TCM commands maximum line pressure.
3. The TCM commands an alternate coast shift pattern where downshifts occur at higher vehicle speeds while coasting.
4. The TCM freezes transmission adaptive functions.
5. The TCM assumes D4 for shifting.
6. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
7. The TCM stores DTC P1826 in TCM history during the consecutive trip in which the Conditions for Setting the DTC are met.

1. A scan tool can clear the DTC.
2. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
3. The TCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the TCM.

The number below refers to the step number on the diagnostic table.

1. 3: This step tests the integrity of the engine harness and TCM by checking for the Signal C state change from HI to LOW. A LOW signal indicates the fault is either in the internal transmission harness or the switch. A HI signal indicates the fault is either in the engine harness or the TCM.

DTC P1826 (3.6L)

The transmission internal mode switch (IMS) is a sliding contact switch attached to the selector detent inside the transmission side cover. The four inputs to the PCM indicate the position of the transmission range selector. The input voltage level at the PCM is high, B+, when the IMS is open and low when the switch is closed to ground. The four input parameters represented are Signals A, B, C and P - Parity. Refer to Transmission Internal Mode Switch Logic .

If the PCM detects that IMS Signal C is high while the vehicle is being driven in a forward gear, then DTC P1826 sets. DTC P1826 is a type B DTC.

This diagnostic procedure supports the following DTC

DTC P1826 Internal Mode Switch C Circuit High Voltage

1. No VSS DTCs P0502 or P0503.
2. Vehicle speed is 16 km/h (10 mph) or more.
3. Engine torque is 27 N.m (20 lb ft) or more.
4. DTC P1826 has not passed this key cycle.

The PCM detects IMS Signal C is high, while the gear ratio indicates first, second, third or fourth gear for 60 seconds.

1. The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
2. The PCM commands maximum line pressure.
3. The PCM freezes transmission adaptive functions.
4. The PCM assumes D4 for shifting.
5. The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame and Failure Records.
6. The PCM stores DTC P1826 in PCM history during the second consecutive trip in which the Conditions for Setting the DTC are met.

1. The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes.
2. A scan tool can clear the MIL/DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
4. The PCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the PCM.

The number below refers to the step number on the diagnostic table.

1. 3: This step tests the integrity of the engine harness and PCM by checking for the Signal C state change from HI to LOW. A LOW signal indicates the fault is either in the internal transmission harness or the switch. A HI signal indicates the fault is either in the engine harness or the PCM.

DTC P1826 (3.8L)

Scheme 91

The torque converter clutch (TCC) release switch is part of the transmission fluid pressure (TFP) manual valve position switch. The TFP manual valve position switch is mounted to the transmission valve body. The TCC release switch is normally-closed.

The switch signals the powertrain control module (PCM) that the TCC is released. This is accomplished by torque converter release fluid pressure acting on the switch contact which opens the circuit. When the circuit voltage is high, the PCM recognizes that the TCC is no longer engaged.

If the PCM determines that the TCC release switch is open indicating that the TCC is not applied and the TCC slip speed indicates that the TCC is applied, then DTC P1887 sets. DTC P1887 is a type B DTC.

This diagnostic procedure supports the following DTC

DTC P1887 Torque Converter Clutch (TCC) Release Switch Circuit

1. No ISS DTC P0716 or P0717.
2. No TCC PWM solenoid valve DTC P2761.
3. The engine speed is greater than 500 RPM for 5 seconds and not in fuel cut off.
4. The TCC is commanded ON.
5. The TCC slip speed is -20 to +60 RPM.
6. The engine torque is 41-407 N.m (30-300 lb ft).

The TCC release pressure switch is open indicating release pressure present for 6 seconds continuous twice during the same ignition cycle.

1. The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
2. The PCM forces the TCC OFF.
3. The PCM inhibits TCC engagement.
4. The PCM inhibits 4th gear if the transmission is in Hot Mode.
5. The PCM freezes transmission adaptive functions.
6. The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame and Failure Records.
7. The PCM stores DTC P1887 in PCM history during the second consecutive trip in which the Conditions for Setting the DTC are met.

1. The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes.
2. A scan tool can clear the MIL/DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
4. The PCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the PCM.

Diagnostic Aids

1. Do not replace the torque converter for this condition, refer to the «Torque Converter Replacement Guide»(/buick/lacrosse/i-2004-2009/remont/automatic-trans/#how-to-diagnosis-troubleshooting-the-automatic-transaxle-4t65-e-service__torque-converter-replacement-guide) for other concerns.
2. Ensure the wiring harness is not stretched too tightly or other components are pressing on the A/T inline 20-way connector body. Also inspect for proper clearance to any other components and wiring. Refer to «Testing for Intermittent Conditions and Poor Connections»(/buick/lacrosse/i-2004-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing) .

The numbers below refer to the step numbers on the diagnostic table.

1. 3: This step tests the PCMs ability to recognize a grounded circuit.
2. 4: A short to ground in this circuit would set DTC P0742.
3. 5: A short to ground in this circuit would set DTC P0742.

DTC P1887 (3.8L)

Scheme 92

The transmission manual shift shaft switch assembly is a sliding contact switch attached to the control valve body within the transmission. The four inputs to the transmission control module (TCM) from the switch indicate which position is selected by the transmission selector lever. This information is used for engine controls as well as determining the transmission shift patterns. The input voltage at the TCM is high when the switch is open and low when the switch is closed to ground. The state of each input is displayed on the scan tool as IMS. The IMS input parameters represented are transmission range Signal A, Signal B, Signal C and Signal P.

If the TCM detects an invalid switch state while the engine is being started, then DTC P1915 sets. DTC P1915 is a type B DTC.

This diagnostic procedure supports the following DTC

DTC P1915 Internal Mode Switch Does Not Indicate Park/Neutral (P/N) During Start

1. The engine speed is greater than 500 RPM.
2. A CRANK request signal has been requested for 409 seconds or more.

The IMS does not indicate PARK or NEUTRAL for 2 seconds or more when attempting to start the vehicle.

1. 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.
2. The TCM commands maximum line pressure.
3. The TCM commands an alternate coast shift pattern where downshifts occur at higher vehicle speeds while coasting.
4. The TCM freezes transmission adaptive functions.
5. The TCM assumes a D4 shift pattern.
6. At the time of the first failure, the TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as a Failure Record.
7. At the time of the second failure, the ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as a Freeze Frame.
8. The TCM stores DTC P1915 in TCM history.

1. The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
2. A scan tool can clear the DTC.
3. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission related diagnostic fault occurring.
4. The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM.

The numbers below refer to the step numbers on the diagnostic table.

1. 3: All HI values, in both Park and Drive 4, indicate the ground circuit is OPEN.
2. 5: With the transmission 20-way connector disconnected, all IMS values should indicate HI.
3. 7: If one circuit affects the other, this indicates a short between the two circuits.
4. 13: This step tests the internal transmission harness. If no fault is found in the harness, the fault will be in the switch.

DTC P1915 (3.6L)

Scheme 93

The transmission control module (TCM) samples the system voltage on the Ignition 1 voltage circuit every 0.1 seconds. Lower than normal voltage may be inadequate to operate the transmission control solenoids properly. Improper solenoid operation may cause erratic transmission operation, which may result in internal damage.

If the TCM detects low voltage on the Ignition 1 voltage circuit, DTC P2534 sets. DTC P2534 is a type A DTC.

This diagnostic procedure supports the following DTC

DTC P2534 Ignition 1 Switch Circuit Low Voltage

The engine is running.

The TCM detects an open or short to ground on the Ignition 1 voltage circuit.

1. The TCM requests the ECM to illuminate the malfunction indicator lamp (MIL).
2. The TCM commands an immediate landing to 2nd gear.
3. The TCM commands maximum line pressure.
4. The TCM freezes transmission adaptive functions.
5. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Freeze Frame and Failure Records.
6. The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as a Freeze Frame.

1. The TCM turns OFF the MIL after the third consecutive trip in which the diagnostic test runs and passes.
2. A scan tool can clear the DTC.
3. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
4. The TCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the TCM.

DTC P2534 (3.6L)

Scheme 94

Ignition voltage is provided to the torque converter clutch pulse width modulation (TCC PWM) solenoid valve. The powertrain control module (PCM) controls the solenoid with a negative duty cycle in order to control application and release of the TCC. When the solenoid is commanded OFF, the PCM senses high voltage. When the solenoid is commanded ON, the PCM senses low voltage.

If the PCM detects a continuous open, short to ground or short to voltage in the TCC PWM valve circuit, then DTC P2761 sets. DTC P2761 is a type B DTC.

This diagnostic procedure supports the following DTC

DTC P2761 Torque Converter Clutch (TCC) Pressure Control (PC) Solenoid Control Circuit

The engine speed is greater than 500 RPM for 5 seconds and not in fuel cut off.

DTC P2761 sets when one of the following conditions exists for at least 5 seconds

1. The PCM commands the solenoid to 70 percent duty cycle or greater and the voltage feedback remains high, B+.
2. The PCM commands the solenoid to 10 percent duty cycle or less and the voltage feedback remains low, 0 volts.

1. The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
2. The PCM inhibits TCC.
3. The PCM inhibits 4th gear if the transmission is in Hot Mode.
4. The PCM freezes transmission adaptive functions.
5. The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame and Failure Records.
6. The PCM stores DTC P2761 in PCM history during the second consecutive trip in which the Conditions for Setting the DTC are met.

1. The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes.
2. A scan tool can clear the MIL/DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
4. The PCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the PCM.

Ensure the wiring harness is not stretched too tightly or other components are pressing on the A/T inline 20-way connector body. Also inspect for proper clearance to any other components and wiring. Refer to Testing for Intermittent Conditions and Poor Connections .

The number below refers to the step number on the diagnostic table.

1. 2: A short to ground in the ignition voltage circuit to the solenoid ahead of the splice would open the fuse and set DTCs for other solenoids on the same circuit. An open in the same circuit would not open the fuse but would set the other DTCs.

DTC P2761 (3.8L)

Scheme 95

Ignition voltage is provided to the torque converter clutch pulse width modulation (TCC PWM) solenoid valve. The transmission control module (TCM) controls the solenoid with a negative 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.

DTC P2763 sets if the TCM detects a short to voltage on the TCC PWM solenoid valve control circuit. 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

1. The engine speed is greater than 500 RPM for 5 seconds.
2. The TCC PWM solenoid valve is commanded ON.

The TCM detects a short to voltage on the TCC PWM solenoid valve control circuit for 4.4 seconds.

1. 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.
2. The TCM commands maximum line pressure.
3. The TCM forces the TCC OFF.
4. The TCM inhibits TCC engagement.
5. The TCM inhibits 4th gear if the transmission is in Hot Mode.
6. The TCM freezes transmission adaptive functions.
7. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Freeze Frame and Failure Records.
8. The TCM stores DTC P2763 in TCM history during the second consecutive trip in which the Conditions for Setting the DTC are met.

1. The ECM turns OFF the MIL after the third consecutive trip in which the TCM does not send an MIL illumination request.
2. A scan tool can clear the MIL/DTC.
3. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
4. The TCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the TCM.

Ensure the wiring harness is not stretched too tightly or other components are pressing on the A/T inline 20-way connector body. Also inspect for proper clearance to any other components and wiring. Refer to Testing for Intermittent Conditions and Poor Connections .

The numbers below refer to the step numbers on the diagnostic table.

1. 3: This step tests the TCM and the wiring to the transmission.
2. 5: This step verifies that the circuit has the correct resistance.

DTC P2763 (3.6L)

Ignition voltage is provided to the torque converter clutch pulse width modulation (TCC PWM) solenoid valve. The TCM controls the solenoid with a negative 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.

DTC P2764 sets if the TCM detects an open or short to ground on the TCC PWM solenoid valve control circuit. 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 speed is greater than 500 RPM for 5 seconds.

The TCM detects an open or short to ground on the TCC PWM solenoid valve control circuit for 4.4 seconds.

1. 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.
2. The TCM commands maximum line pressure.
3. The TCM forces the TCC OFF.
4. The TCM inhibits TCC engagement.
5. The TCM inhibits 4th gear if the transmission is in Hot Mode.
6. The TCM freezes transmission adaptive functions.
7. The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Freeze Frame and Failure Records.
8. The TCM stores DTC P2764 in TCM history during the second consecutive trip in which the Conditions for Setting the DTC are met.

1. The ECM turns OFF the MIL after the third consecutive trip in which the TCM does not send an MIL illumination request.
2. A scan tool can clear the MIL/DTC.
3. The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
4. The TCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the TCM.

Ensure the wiring harness is not stretched too tightly or other components are pressing on the A/T inline 20-way connector body. Also inspect for proper clearance to any other components and wiring. Refer to Testing for Intermittent Conditions and Poor Connections .

The number below refers to the step number on the diagnostic table.

1. 2: A short to ground in the ignition 1 voltage circuit to the solenoid ahead of the splice would open the fuse and set DTCs for other solenoids on the same circuit. An open in the same circuit would not open the fuse but would set the other DTCs.

DTC P2764 (3.6L)

See also:
• Transmission Internal Mode Switch Logic
• Diagnostic System Check - Vehicle
• Testing for Intermittent Conditions and Poor Connections
• Testing for Short to Ground
• Wiring Repairs
• Wiring Harness Replacement
• MANUAL SHIFT SHAFT POSITION (INTERNAL MODE) SWITCH AND PARKING SYSTEM COMPONENTS REMOVAL
• Control Module References
• Diagnostic Trouble Code (DTC) List - Vehicle
• Special Tools
• Automatic Transmission Inline 20-Way Connector End View (3.6L)
• Testing for Continuity
• Circuit Testing
• Torque Converter Replacement Guide
• TORQUE CONVERTER ASSEMBLY REMOVAL
• Automatic Transmission Range Selector Cable Adjustment