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 Volts

High Side Driver 2 CKT Status

Open/Short to GND

Open/Short to GND

Short to Volts

Scan Tool Parameter Data

Circuit

Normal Circuit Voltage

Scan Data - Circuit Open

Scan Data - Circuit Grounded

Scan Data - Circuit Shorted to Voltage

Shift Sol. 2 CKT Status

OK

Open

Short to GND

Short to Volts

High Side Driver 2 CKT Status

OK

Open/Short to GND

Open/Short to GND

Short to Volts

Circuit/System Description

The shift solenoid (SS) 2 is part of the control solenoid (w/body and TCM) valve assembly. The assembly is attached to the lower control valve body and has no serviceable parts. The shift solenoid is a normally closed (NC), On/Off solenoid. When the TCM opens the solenoid ground circuit, (solenoid off) solenoid signal fluid exhausts and the clutch select valve 3 moves to the non-apply position. The TCM shifts the transmission by operating the solenoids in on/off combinations. Solenoid power is supplied by the TCM through a high side driver (HSD). The HSD protects the circuits and components that the TCM powers. Should the circuit overload the driver will shutdown. After the overload is removed the HSD reset.

Conditions for Running the DTC

    • The engine run time is greater than 5 seconds.
    • The SS 2 is commanded ON or OFF.

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.

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.

Action Taken When the DTC Sets

    • DTCs P0976 and P0977 are Type A DTCs.
    • 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

DTCs P0976 and P0977 are Type A DTCs.

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

Electrical Information Reference

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

Description and Operation

Electronic Component Description

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

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.

    • Control solenoid (w/body and TCM) valve assembly replacement. Refer to Control Module References for replacement, setup, and programming.
    • Perform the Service Fast Learn Adapts if internal transmission repairs are performed.