GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Holden 🢒 2008 🢒 Epica 🢒 DTC 🢒 DTC P0962

Circuit Description

The line pressure control (PC) solenoid valve (SLT) regulates solenoid modulator fluid passing through the solenoid into throttle signal pressure. The transmission control module (TCM) uses a pulse width modulated signal in order to control the signal pressure. The TCM compares various inputs in order to determine the appropriate pressure for a given load. The TCM varies the current to the line PC solenoid valve from 0.1 amps, for maximum line pressure to 1.1 amps, for minimum line pressure. An internal current monitor within the TCM provides feedback in order to determine actual line PC solenoid valve current draw.

If the TCM detects a continuous open or short to ground in the line PC solenoid valve circuit, then DTC P0962 sets. DTC P0962 is a type A DTC.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0962 Line Pressure Control (PC) Solenoid Control Circuit Low Voltage

Conditions for Running the DTC
    • The engine speed is 400 RPM or greater.
    • The ignition voltage is 10.2-15.5 volts.
    • Trans. protection mode is OFF.

Conditions for Setting the DTC

The line PC solenoid valve feedback circuit indicates a continuous open or short to ground for 12.5 seconds or greater.

Action Taken When the DTC Sets
    • The TCM requests the powertrain control module (PCM) to illuminate the malfunction indicator lamp (MIL).
    • The TCM turns the Trans. Protection Mode ON.
    • The transmission will operate in 5th gear when the transmission is shifted into D or I range and 2nd gear when shifted into L range.
    • The line pressure is at maximum.
    • The torque converter clutch (TCC) is disabled.
    • The TCM freezes the transmission adaptive functions.
    • The PCM records the operating conditions when the Condition for Setting the DTC are met. The PCM 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 a Failure Record.
    • The TCM stores DTC P0962 in TCM history.

Conditions for Clearing the MIL/DTC
    • The PCM 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 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. This step verifies the ability of the TCM to command the line PC solenoid valve.

    2.

  2. This step verifies that the automatic transmission wiring harness and the line PC solenoid valve have correct resistance.

Step

Action

Values

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

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 PCM and the TCM Failure Records. Using the Clear Eng./Trans. DTC Info function erases the Failure Records from the powertrain control module (PCM) and the transmission control module (TCM).
       • Using the Clear Eng./Trans. DTC Info function erases stored DTCs in both the PCM and TCM.

  3. Record the DTC Failure Records.
  4. Clear the DTC.
  5. Start the engine.
  6. With a scan tool select Line PC Solenoid Output Controls.
  7. With a scan tool, increase and decrease the PC solenoid amperage.
  8. Observe the scan tool display.

Does the Line pressure control (PC) Sol. Actual Current reading vary from the Line PC Sol. Ref. Current reading by more than the specified amount?

0.05 amps

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections

3

  1. Turn OFF the ignition.
  2. Disconnect the AT inline 14-way connector. Additional DTCs may set.
  3. Using the DMM and the J 35616 GM Terminal Test Kit, measure the resistance between low control and high control circuits of the line PC solenoid valve at the transmission side of the AT inline 14-way connector.

Is the resistance within the specified range?

3.8-8.3 ohms

Go to Step 7

Go to Step 4

4

Is the resistance greater than the specified value?

8.3 ohms

Go to Step 5

Go to Step 6

5
  1. Test the high control circuit of the line PC solenoid valve for an open between the AT inline 14-way connector and the line PC solenoid valve.
  2. Test the low control circuit of the line PC solenoid valve for an open between the AT inline 14-way connector and the line PC solenoid valve.

Refer to Testing for Continuity .

Did you find a condition?

--

Go to Step 18

Go to Step 19

6

Test the high control circuit and the low reference circuit of the line PC solenoid valve for being shorted together between the AT inline 14-way connector and the line PC solenoid valve. Refer to Testing for Short to Ground .

Did you find the condition?

--

Go to Step 18

Go to Step 19

7

Measure the resistance from high control circuit of the line PC solenoid valve at the transmission side of the AT inline 14-way connector to ground.

Is the resistance less than the specified value?

10 ohms

Go to Step 8

Go to Step 9

8
  1. Test the high control circuit of the line PC solenoid valve for a short to ground between the AT inline 14-way connector and the line PC solenoid valve.
  2. Test the low reference circuit of the line PC solenoid valve for a short to ground between the AT inline 14-way connector and the line PC solenoid valve.

Refer to Testing for Short to Ground .

Did you find a condition?

--

Go to Step 18

Go to Step 19

9

Measure the resistance between the high control circuit of the line PC solenoid valve and all other circuits, except the low control circuit of the line PC solenoid valve at the transmission side of the AT inline 14-way connector.

Is the resistance less than the specified value?

100 ohms

Go to Step 18

Go to Step 10

10
  1. Disconnect the TCM. Additional DTCs may set.
  2. Using the DMM and the J 35616 , measure the resistance from the low control circuit of the line PC solenoid valve at the harness side of the AT inline 14-way connector to ground.

Is the resistance less than the specified value?

10 ohms

Go to Step 11

Go to Step 12

11

Test the low reference circuit of the line PC solenoid valve for a short to ground between the TCM connector and the AT inline 14-way connector. Refer to Testing for Short to Ground .

Did you find and correct the condition?

--

Go to Step 21

--

12

Using the DMM and the J 35616 , measure the resistance between the low control circuit of the line PC solenoid valve at the harness side of the AT inline 14-way connector and terminal 15 of the TCM C2 connector.

Is the resistance less than the specified value?

10 ohms

Go to Step 14

Go to Step  13

13

Test the low reference circuit of the line PC solenoid valve for an open between the TCM connector and the AT inline 14-way connector. Refer to Testing for Continuity .

Did you find and correct the condition?

--

Go to Step 21

--

14

Using the DMM and the J 35616 , measure the resistance from high control circuit of the line PC solenoid valve at the harness side of the AT inline 14-way connector to ground.

Is the resistance less than the specified value?

10 ohms

Go to Step 15

Go to Step 16

15

Test the high control circuit of the line PC solenoid valve for a short to ground between the TCM connector and the AT inline 14-way connector. Refer to Testing for Short to Ground .

Did you find and correct the condition?

--

Go to Step 21

--

16

Using the DMM and the J 35616 , measure the resistance of the high control circuit of the line PC solenoid valve between the harness side of the AT inline 14-way connector and the TCM connector.

Is the resistance less than the specified value?

10 ohms

Go to Step 20

Go to Step 17

17

Test the high control circuit of the line PC solenoid valve for an open between the TCM connector and the AT inline 14-way connector. Refer to Testing for Continuity .

Did you find and correct the condition?

--

Go to Step 21

--

18

Replace the automatic transmission wiring harness.

Is the action complete?

--

Go to Step 21

--

19

Replace the control valve body assembly. Refer to Control Valve Body Cover Replacement .

Is the action complete?

--

Go to Step 21

--

20

Replace the TCM. Refer to Control Module References for replacement, setup, and programming.

Is the action complete?

--

Go to Step 21

--

21

Perform the following procedure in order to verify the repair:

  1. Select DTC.
  2. Select Clear Info.
  3. Operate the vehicle under the following conditions:
    4. • Start and idle the engine.
    • System voltage must be at least 11 volts.
  4. Select Specific DTC.
  5. Enter DTC P0962.

Does the DTC reset?

--

Go to Step 2

Go to Step 22

22

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

System OK