GM Service Manual Online
For 1990-2009 cars only

Object Number: 882394  Size: MF
Master Electrical Component List
Automatic Transmission Controls Schematics
OBD II Symbol Description Notice

Circuit Description

The transmission control module (TCM) uses the TCC pressure control solenoid valve to apply and release the TCC system. The TCC pressure control solenoid valve is attached to the control solenoid valve assembly. The TCM compares engine and transmission inputs to determine if TCC should be applied. The TCM then regulates the pressure by applying a varying amperage to the TCC pressure control solenoid valve. The TCM then monitors the amperage at the return line.

When the TCM detects a significant difference between commanded and actual current in the TCC pressure control solenoid valve circuit, DTC P0965 sets. DTC P0965 is a type B DTC.

Conditions for Running the DTC

    • No TCC pressure control solenoid DTC P0964 or P0966.
    • The ignition voltage is 8-18 volts.
    • The engine speed is greater than 500 RPM for 5 seconds.

Conditions for Setting the DTC

The TCM detects that the actual current flowing through the circuit is outside of a calibrated current threshold for the current commanded duty cycle for 2 seconds.

Action Taken When the DTC Sets

    • The TCM requests the engine control module (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 inhibits TCC engagement.
    • The TCM turns the power off to the TCC enable solenoid valve and the TCC pressure control solenoid valve. This results in harsher garage shifts and no TCC engagement.
    • The TCM no longer inhibits shifting between reverse and drive when moving.
    • The TCM commands maximum pressure to the input clutch.
    • The TCM freezes garage shift transmission adaptive functions.
    • The TCM freezes torque converter clutch (TCC) 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 P0965 in TCM history during the second consecutive trip in which the Conditions for Setting the DTC are met.

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 DTC default actions when the ignition switch is OFF long enough in order to power down the TCM.

Diagnostic Aids

    • Inspect the connectors at the TCM, the transmission, and all other circuit connecting points for an intermittent condition. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
    • Inspect the circuit wiring for an intermittent condition. Refer to Testing for Electrical Intermittents in Wiring Systems.

Step

Action

Values

Yes

No

1

Did you perform the Diagnostic System Check - Engine Controls?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls in Engine Controls - 2.2L (L61)

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 Failure Records. Using the Clear Eng./Trans. DTC Info function erases the Failure Records from the TCM.
       • Using the Clear Eng./Trans. DTC Info function erases stored DTCs in both the ECM and TCM.

  4. Record the DTC Failure Records.
  5. Clear the DTC.
  6. Turn OFF the ignition for 30 seconds.
  7. Start the engine.
  8. Select Specific DTC.
  9. Enter DTC P0965.

Does the DTC fail this ignition?

--

Go to Step 3

Go to Intermittent Conditions in Engine Controls - 2.2L (L61)

3

Using the scan tool, monitor Ignition Voltage.

Is Ignition Voltage below the specified value?

11 V

Go to DTC P0562

Go to Step 4

4

Test the low control circuit (CKT 5500) of the TCC pressure control solenoid valve for a short to ground.

Refer to Testing for Short to Ground and Wiring Repairs in Wiring Systems.

Did you find and correct a condition?

--

Go to Step 13

Go to Step 5

5

  1. Turn OFF the ignition .
  2. Connect the AT inline 20-way connector.
  3. Disconnect the TCM C2 64-way connector.
  4. Using the DMM and the J-35616 Connector Test Adapter Kit, measure the resistance between the terminal C2-50 and terminal C2-51.

Is the resistance value within the specified range?

2.8-6.8 ohms

Go to Step 10

Go to Step 6

6

Using the DMM and the J-35616 , measure the resistance between the terminal C2-50 and terminal C2-51.

Is the resistance less the specified value?

2.8 ohms

Go to Step 7

Go to Step 8

7

Test the high control circuit (CKT 418) for a short to the low control circuit (CKT 5500) of the TCC pressure control solenoid valve. Refer to Testing for Continuity and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 11

8

  1. Test the high control circuit (CKT 418) of the TCC pressure control solenoid valve for high resistance.
  2. Test the low control circuit (CKT 5500) of the TCC pressure control solenoid valve for high resistance.

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 9

9

Inspect for faulty connections at the transmission. Refer to Circuit Testing and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 11

10

Inspect for faulty connections at the TCM. Refer to Circuit Testing and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 12

11

Replace the TCC pressure control solenoid valve. The TCC pressure control solenoid valve is part of the control solenoid valve assembly. Refer to Control Valve Body Assembly Disassemble .

Did you complete the replacement?

--

Go to Step 13

--

12

Replace the TCM. Refer to Transmission Control Module Replacement .

Did you complete the replacement?

--

Go to Step 13

--

13

Perform the following procedure in order to verify the repair:

  1. Select DTC.
  2. Select Clear Info.
  3. Operate the vehicle within the conditions for running the DTC as specified in the supporting text.
  4. Select Specific DTC.
  5. Enter DTC P0965.

Has the test run and passed?

--

Go to Step 14

Go to Step 2

14

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 in Engine Controls - 2.2L (L61)

System OK