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 P0973:  Shift Solenoid (SS) 1 Control Circuit Low Voltage

DTC P0974:  Shift Solenoid (SS) 1 Control Circuit High Voltage

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Shift Solenoid (SS) 1 Control

P0973

P0974

P0974

--

Shift Solenoid (SS) 1 High Side Driver 2

P1833

P1833

P1834

--

Typical Scan Tool Data

Shift Solenoid (SS) 1

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Operating Conditions: Engine running, normal operating temperature

Parameter Normal Range: OK

Shift Sol. 1 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

Circuit/System Description

The shift solenoid (SS) 1 is part of the control solenoid (w/body and TCM) valve assembly and is not serviced separately. The control solenoid (w/body and TCM) valve assembly supplies 12 volts to SS 1 on the high side driver 2 circuit. The control solenoid (w/body and TCM) valve assembly controls the normally closed SS 1 on the SS 1 control circuit. The SS 1 controls the transmission fluid to the Mode-2 valve. In the OFF position no oil is supplied to the clutch pressure control (PC) solenoid 3 or the transmission fluid pressure (TFP) switch 5, and the 4-5-6 clutch is fed by drive fluid. In the ON position, Reverse fluid is allowed to flow and is supplied to the 3-5-R clutch.

Conditions for Running the DTC

P0973

    • DTC P0973 is not set.
    • Start the ignition voltage, run the engine.

P0974

    • DTC P0974 is not set.
    • Start the ignition voltage, run the engine.

Conditions for Setting the DTC

P0973

    • The control solenoid (w/ body and TCM) assembly detects a internal low voltage electrical malfunction of the SS 1 control circuit.
    • Last for 1.2 seconds in the 1.5 seconds sample time.

P0974

    • The control solenoid (w/ body and TCM) assembly detects a internal high voltage electrical malfunction of the SS 1 control circuit.
    • Last for 1.2 seconds in the 1.5 seconds sample time.

Action Taken When the DTC Sets

    • DTC P0973 and P0974 are Type B 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

    • DTC P0973 is a type A DTC.
    • DTC P0974 is a type B DTC.

Diagnostic Aids

When attempting to set solenoid electrical DTCs, ensure the control solenoid (w/body and TCM) valve assembly is warmed up and the transmission is operated in 2nd gear long enough to ensure a 3°C (5°F) increase in TCM 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

    •  Automatic Transmission Inline 16-Way Connector End View
    •  Automatic Transmission Internal Connector End Views
    •  Automatic Transmission Related 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 2nd gear long enough to ensure at least a 3°C (5°F) rise in TCM temperature.
  3. Place the gear selector in Reverse for 5 seconds and then idle vehicle for 5 seconds.
  4. Observe the scan tool data parameter Shift Sol. 1 CKT Status. The parameter should display OK.
  5. ⇒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.

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