GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2006 🢒 Vibe - FWD 🢒 Restraints 🢒 SIR 🢒 DTC P0787

Circuit Description

The 2nd brake control solenoid is located in the control valve body of the transmission. The powertrain control module (PCM) turns the 2nd brake solenoid ON or OFF, this controls the application or release of the reverse clutch, which in turn reduces shift shock between transmission shift points.

When the PCM detects a continuous short to ground in the 2nd brake control solenoid circuit, then DTC P0787 sets. DTC P0787 is a type A DTC.

Conditions for Running the DTC

PCM detects a short in the solenoid circuit 4 times.

Conditions for Setting the DTC

DTC P0787 sets when either of the following conditions occurs:

The PCM detects a short to ground in the solenoid circuit when the solenoid is commanded ON/OFF.

Action Taken When the DTC Sets
    • At the time of the first failure, the PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as a Failure Record.
    • The PCM illuminates the malfunction indicator lamp (MIL) during the first consecutive drive trip in which the Conditions for Setting the DTC are met.
    • The PCM stores DTC P0787 in PCM history.

Conditions for Clearing the MIL/DTC
    • A scan tool can clear the MIL/DTC.
    • The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission related diagnostic fault occurring.

Test Description

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

  1. Listen for an audible click when the solenoid energizes.

Step

Action

Value(s)

Yes

No

Schematic Reference: Automatic Transmission Controls Schematics

1

Did you perform the Diagnostic System Check - Vehicle?

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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 PCM Freeze Frame Failure Records. Using the Clear Info function erases the Freeze Frame Failure Records from the powertrain control module (PCM).
       • Using the Clear Info function erases stored DTCs in the PCM.

  3. Record the DTC Freeze Frame and Failure Records.
  4. Clear the DTC.
  5. Use the scan tool in order to command the shift solenoid ON.

Does the solenoid operate?

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Go to Step 5

Go to Step 3

3
  1. Turn OFF the ignition.
  2. Disconnect the PCM.
  3. Test the circuit from the PCM to the shift solenoid for a short to ground. Refer to Testing for Short to Ground in Wiring Systems.

Did you find a condition?

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Go to Step 6

Go to Step 5

4
  1. Remove the transmission oil pan.
  2. Test the shift solenoid wiring from the 10-way connector to the shift solenoid connector for the following conditions:

    3. Short to ground--Refer to Testing for Short to Ground in Wiring Systems.

Did you find a condition?

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Go to Step 7

Go to Step 8

5

Replace the PCM. Refer to Powertrain Control Module Programming and Setup in Programming and Setup.

Is the action complete?

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Go to Step 9

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6

Perform the necessary wiring repairs. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

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Go to Step 9

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7

Replace the internal transmission wiring harness. Refer to Solenoids and Wiring Harness Replacement .

Is the action complete?

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Go to Step 9

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8

Replace the 2nd brake control solenoid. Refer to Solenoids and Wiring Harness Replacement .

Is the action complete?

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Go to Step 9

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9

Perform the following procedure in order to verify the repair:

  1. Select DTC.
  2. Select Clear Info.
  3. Turn ON the ignition, with the engine OFF.
  4. Select Specific DTC.
  5. Enter DTC P0787.

Has the test run and passed?

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Go to Step 10

Go to Step 2

10

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?

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Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

System OK