GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC P0976:  Shift Solenoid (SS) 2 Control Circuit Low Voltage

DTC P0977:  Shift Solenoid (SS) 2 Control Circuit High Voltage

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Shift Solenoid (SS) 2 Control

P0976

P0977

P0977

--

Shift Solenoid (SS) 2 High Side Driver 2

P1833

P1833

P1834

--

Typical Scan Tool Data

Shift Solenoid (SS) 2

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Operating Conditions: Engine running, normal operating temperature

Parameter Normal Range: OK

Shift Sol. 2 CKT Status

Short to GND

Open

Short to Voltage

High Side Driver 2 CKT Status

Open/Short to GND

Open/Short to GND

Short to Voltage


Typical Scan Tool Data

Circuit

Normal Circuit Voltage

Scan Data - Circuit Open

Scan Data - Circuit Grounded

Scan Data - Circuit Shorted to Voltage

Shift Sol. 2 circuit Status

Operational

Open

Short to Ground

Shorted to Voltage

High Side Driver 2 Circuit Status

Operational

Open/Short to GND

Open/Short to GND

Shorted to Voltage

Circuit/System Description

The shift solenoid (SS) 2 is part of the control solenoid (w/body and TCM) valve assembly and is not serviced separately. The TCM supplies 12 volts to SS 2 on the high side driver 2 circuit. The TCM controls the normally closed SS 2 on the SS 2 control circuit. The SS 2 controls the transmission fluid to the Mode-3 valve. In the ON position the 4-5-6 clutch is fed by drive fluid. In the OFF position, Reverse fluid is allowed to flow and is supplied to the low and reverse clutch and the 4-5-6 clutch assemblies.

Conditions for Running the DTC

P0976

    • DTC P0976 is not set.
    • Start the ignition voltage, run the engine.

P0977

    • DTC P0977 is not set.
    • Start the ignition voltage, run the engine.

Conditions for Setting the DTC

P0976

    • The TCM detects an internal low voltage electrical malfunction of the SS 2 control circuit when the SS 2 is commanded OFF for 300 milliseconds.
    • Last for 1.2 seconds in the 1.5 seconds sample time.

P0977

    • The TCM detects an internal high voltage electrical malfunction of the SS 2 control circuit when the SS 2 is commanded ON for 300 milliseconds.
    • Last for 1.2 seconds in the 1.5 seconds sample time.

Action Taken When the DTC Sets

    • DTC P0976 is a type B DTC.
    • The TCM defaults the transmission to 3rd gear if the current gear is 1st, 2nd, or 3rd, or 5th gear if the current gear is 4th, 5th, or 6th gear.
    • The TCM inhibits the torque converter clutch (TCC).
    • The TCM commands maximum line pressure.
    • The TCM freezes transmission adaptive functions.

Conditions for Clearing the DIC/DTC

    • DTC P0976 is a type B DTC.
    • DTC P0977 is a type A DTC.

Diagnostic Aids

When attempting to set solenoid electrical DTCs, ensure the TCM is warmed up and the transmission is operated in 2nd gear long enough to ensure a 3°C (5°F) increase in TCM substrate temperature. This will place the TCM under the optimal conditions to test solenoid electrical DTCs.

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Component Connector End Views

DTC Type Reference

    •  Diagnostic Trouble Code (DTC) Type Definitions
    •  Diagnostic Trouble Code (DTC) List/Type

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

    •  Scan Tool Output Controls
    •  Scan Tool Data List
    •  Scan Tool Data Definitions

Circuit/System Testing

  1. Ensure the transmission fluid temperature is between 50-80°C (122-176°F).
  2. Operate the vehicle in 4th, 5th, or 6th gear with TCC applied, long enough to ensure at least a 3°C (5°F) rise in TCM substrate temperature.
  3. Observe the scan tool data parameter Shift Sol. 2 CKT Status. The parameter should display OK.
  4. If the parameter displays Open, Short to Volts, Short to GND, or if the DTC resets, perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection.
    If no concerns are found during the inspection, replace the control solenoid (w/body and TCM) valve assembly.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Service Fast Learn Adapts
    •  Control Module References for TCM replacement, setup, and programming