GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2009 🢒 Vibe - FWD 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC P0976 or P0977

Circuit Description

Shifting from 1st to 4th is performed in combination with "ON" and "OFF" operation of the shift solenoid valves S1 and S2 which is controlled by the engine control module (ECM). If an open or short circuit occurs in either of the shift solenoid valves, the ECM controls the remaining normal shift solenoid valve to allow the vehicle to be operated smoothly (fail safe function). The ECM will illuminate the MIL and store the DTC.

DTC Descriptor

This diagnostic procedure supports the following DTC:

    • DTC P0976 Shift Solenoid "B" Control Circuit Low (Shift Solenoid Valve S2)
    • DTC P0977 Shift Solenoid "B" Control Circuit High (Shift Solenoid Valve S2)

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

P0976

The ECM detects short in solenoid valve S2 circuit two times when valve is operated.

P0977

The ECM detects an open in solenoid valve S2 circuit two times when solenoid valve in not operated.

Action Taken When the DTC Sets
    • DTCs P0976 and P0977 are type C DTCs.
    • The malfunction indicator lamp (MIL) illuminates the first time the diagnostic runs with the fault active.

Conditions for Clearing the MIL/DTC

The DTC will clear when conditions for setting the DTC have been repaired.

Step

Action

Values

Yes

No

Schematic Reference: Automatic Transmission Controls Schematics

Connector End View Reference: Component Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle

2
  1. Turn the ignition to OFF.
  2. Disconnect the transmission connector B90.
  3. Measure the resistance between terminal 10 and body ground.

Is the resistance measured within specified value?

11 to 15 Ohms

Go to Step 3

Go to Step 4

3
  1. Connect the transmission connector B90.
  2. Disconnect the ECM connector C19.
  3. Measure the resistance between connector C19 terminal 78 and body ground.

Is the resistance measured within specified value?

11 to 15 Ohms

Go to Step 8

Go to Step 5

4
  1. Turn the ignition to OFF.
  2. Remove the shift solenoid valve S2.
  3. Measure the resistance between shift solenoid valve terminal and the shift solenoid body.
  4. Connect the positive lead to the terminal of the solenoid connector and the negative lead to the solenoid body, then check the movement of the valve.

Is the resistance measured within specified value and does the solenoid make an operating sound?

11 to 15 Ohms

Go to Step 6

Go to Step 7

5

Repair or replace harness or connector of the ECM. Refer to Wiring Repairs and Connector Repairs.

Did you complete the repair or replacement?

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Go to Step 9

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6

Repair or replace harness or connector of the shift solenoid valve S2. Refer to Wiring Repairs and Connector Repairs.

Did you complete the repair or replacement?

--

Go to Step 9

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7

Replace the shift solenoid valve S2.

Did you complete the replacement?

--

Go to Step 9

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8

Replace the ECM. Refer to Control Module References.

Did you complete the replacement?

--

Go to Step 9

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9
  1. Use the scan tool in order to clear the DTC.
  2. Operate the vehicle within the Conditions for Running the DTC, as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK