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For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2006 🢒 GTO 🢒 DTC 🢒 DTC P2764

Circuit Description

The torque converter clutch pulse width modulation (TCC PWM) solenoid valve controls the fluid acting on the converter clutch valve. The converter clutch valve controls the TCC application and release. The solenoid attaches to the control valve body within the transmission. The solenoid receives voltage through the ignition 1 voltage circuit. The transmission control module (TCM) controls the solenoid by providing a ground path on the TCC PWM solenoid valve control circuit. Current flows through the solenoid coil according to the duty cycle, percentage of ON and OFF time. The TCC PWM solenoid valve provides a smooth engagement of the TCC by operating during a duty cycle percent of ON time.

When the TCM detects a continuous open or short to ground in the TCC PWM solenoid valve control circuit, then DTC P2764 sets. DTC P2764 is a type A DTC.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P2764 Torque Converter Clutch (TCC) Pressure Control (PC) Solenoid Control Circuit Low Voltage

Conditions for Running the DTC
    • The system voltage is 8-18 volts.
    • The engine speed is 500 RPM for 5 seconds.

Conditions for Setting the DTC

DTC P2764 sets when either of the following conditions occurs for 5 seconds:

    • The TCM detects an open in the TCC PWM shift solenoid valve circuit when the TCC PWM is commanded ON.
    • The TCM detects a short to ground in the TCC PWM shift solenoid valve circuit when the TCC PWM is commanded ON.

Action Taken When the DTC Sets
    • 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 TCC engagement.
    • The TCM inhibits 4th gear if in hot mode.
    • 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.
    • 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.
    • The TCM stores DTC P2764 in TCM history during the second consecutive trip in which the Conditions for Setting the DTC are met.

Conditions for Clearing the DTC
    • The ECM turns OFF the MIL after the 4th 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.

Test Description

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

  1. This step tests for voltage to the solenoid.

    2.

  2. This step tests the ability of the TCM and wiring to control the ground circuit.

    3.

  3. This step tests the resistance of the TCC PWM solenoid valve and the automatic transmission (AT) wiring harness.

DTC P2764

Step

Action

Values

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
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.

    3. Important: Before clearing the DTC, use the scan tool in order to record the Freeze Frame and Failure Records. Using the Clear Info function erases the Freeze Frame and Failure Records from the transmission control module (TCM).

  3. Record the DTC Freeze Frame and Failure Records.
  4. Clear the DTC.

Are any of the following DTCs also set?

    • P0787
    • P0973
    • P0976
    • P2769

--

Go to Step 3

Go to Step 4

3

Inspect the ACC/TCM fuse for an open.

Refer to Circuit Protection - Fuses in Wiring Systems.

Is the fuse open?

--

Go to Step 11

Go to Step 4

4

  1. Turn OFF the ignition.
  2. Disconnect the automatic transmission (AT) inline 20-way connector, additional DTCs may set.
  3. Install the J 44152 Jumper Harness (20 pins) on the engine side of the AT inline 20-way connector.
  4. Turn ON the ignition, with the engine OFF.
  5. Using the J 35616 GM Terminal Test Kit, connect a test lamp from the TCC PWM ignition 1 voltage circuit of the J 44152 to ground.

Refer to Automatic Transmission Inline 20-Way Connector End View .

Does the test lamp illuminate?

--

Go to Step 5

Go to Step 14

5

  1. Connect the test lamp between the torque converter clutch/pulse width modulation (TCC PWM) solenoid valve ignition voltage and control circuits of the J 44152 .

    2. Refer to Automatic Transmission Inline 20-Way Connector End View .

  2. Use the scan tool in order to command the TCC PWM solenoid valve ON and OFF three times.

Does the test lamp turn ON and OFF with each command?

--

Go to Step 7

Go to Step 6

6

Is the test lamp always ON?

--

Go to Step 15

Go to Step 16

7

  1. Install the J 44152 on the transmission side of the AT inline 20-way connector.
  2. Using the DMM and the J 35616 , measure the resistance between the TCC PWM solenoid valve ignition voltage and control circuits of the J 44152 .

    3. Refer to Testing for Continuity in Wiring Systems.

Refer to Automatic Transmission Inline 20-Way Connector End View .

Does the resistance measure within the specified range?

10-15 ohms

Go to Step 8

Go to Step 9

8

Measure the resistance from the TCC PWM solenoid valve ignition voltage and control circuits to ground.

Refer to Testing for Continuity in Wiring Systems.

Do both readings measure greater than the specified value?

250 K ohms

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 10

9
  1. Disconnect the AT wiring harness from the TCC PWM solenoid valve.
  2. Measure the resistance of the TCC PWM solenoid valve.

Refer to Testing for Continuity in Wiring Systems.

Does the resistance measure within the specified range?

10-15 ohms

Go to Step 17

Go to Step 18

10
  1. Disconnect the AT wiring harness assembly from the TCC PWM solenoid valve.
  2. Measure the resistance from each of the component terminals to ground.

Refer to Testing for Continuity in Wiring Systems.

Do both readings measure greater than the specified value?

250 K ohms

Go to Step 17

Go to Step 18

11

Important: The condition that affects this circuit may exist in other connecting branches of the circuit. Refer to Power Distribution Schematics in Wiring Systems for complete circuit distribution.

Test the ignition circuit of the TCC PWM solenoid valve for a short to ground between the fuse block 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 20

Go to Step 12

12

Important: The condition that affects this circuit may exist in other connecting branches of the circuit. Refer to Power Distribution Schematics in Wiring Systems for complete circuit distribution.

Test the ignition circuit of the TCC PWM solenoid valve for a short to ground between the AT inline 20-way connector and the TCC PWM solenoid valve.

Refer to Testing for Short to Ground in Wiring Systems.

Did you find a short to ground condition?

--

Go to Step 17

Go to Step 13

13
  1. Test each solenoid for a short to ground.
  2. Replace the faulty solenoid as necessary.

Did you complete the replacement?

--

Go to Step 20

--

14

Important: The condition that affects this circuit may exist in other connecting branches of the circuit. Refer to Power Distribution Schematics in Wiring Systems for complete circuit distribution.

Test the ignition circuit of the TCC PWM solenoid valve for an open.

Refer to Testing for Continuity and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 20

--

15

Test the control circuit of the TCC PWM solenoid valve for a short to ground between the TCM 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 20

Go to Step 19

16

Test the control circuit of the TCC PWM solenoid valve for an open between the TCM 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 20

Go to Step 19

17

Replace the AT wiring harness. Refer to Torque Converter Clutch Pulse Width Modulation Solenoid, Torque Converter Clutch Solenoid, and Wiring Harness .

Did you complete the replacement?

--

Go to Step 20

--

18

Replace the TCC PWM solenoid valve. Refer to Torque Converter Clutch Pulse Width Modulation Solenoid, Torque Converter Clutch Solenoid, and Wiring Harness .

Did you complete the replacement?

--

Go to Step 20

--

19

Replace the TCM.

Refer to Control Module References in Computer/Integrating Systems for replacement, setup and programming.

Did you complete the replacement?

--

Go to Step 20

--

20

Perform the following procedure in order to verify the repair:

  1. Select DTC.
  2. Select Clear Info.
  3. Drive the vehicle in D4 with the TCC ON and ensure that the TCC Duty Cycle CKT status parameter displays OK for 5 seconds.
  4. Select Specific DTC.
  5. Enter DTC P2764.

Has the test run and passed?

--

Go to Step 21

Go to Step 2

21

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