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 P0969: Clutch Pressure Control (PC) Solenoid 3 System Performance

DTC P0970: Clutch Pressure Control (PC) Solenoid 3 Control Circuit Low Voltage

DTC P0971: Clutch Pressure Control (PC) Solenoid 3 Control Circuit High Voltage

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Clutch PC Solenoid 3 Control

P0970

P0971

P0971

P0969

Circuit/System Description

The clutch pressure control (PC) solenoid 3 is part of the control solenoid (w/body and TCM) valve assembly. The control solenoid (w/body and TCM) valve assembly has no seviceable parts. The TCM supplies 12 volts to the clutch PC solenoid 3 on the high side driver circuit. The TCM controls the clutch PC solenoid 3 through the clutch PC solenoid 3 control circuit. The normally high clutch PC solenoid 3 flows fluid to the low and reverse clutch and 4-5-6 clutch assemblies when commanded ON and exhausts fluid when commanded OFF. This allows the clutch PC solenoid 3 to regulate the transmission fluid pressure to the low and reverse clutch and 4-5-6 clutch assemblies.

Conditions for Running the DTC

P0969

    • The engine run time is greater than 12 seconds.
    • The ignition voltage is between 9.0 volts and 19.0 volts.
    • The clutch PC solenoid 3 is commanded ON.
    • DTC P0969 has not failed this ignition cycle.

P0970

    • The engine run time is greater than 5 seconds.
    • The ignition voltage is between 9.0 volts and 19.0 volts.
    • The clutch PC solenoid 3 is commanded ON.
    • DTC P0970 has not failed this ignition cycle.

P0971

    • The engine run time is greater than 5 seconds.
    • The ignition voltage is between 9.0 volts and 19.0 volts.
    • The clutch PC solenoid 3 is commanded ON.
    • DTC P0971 has not failed this ignition cycle.

Conditions for Setting the DTC

P0969

The TCM detects an internal electrical performance malfunction of the clutch PC solenoid 3 control circuit where the actual low and reverse/4-5-6 clutch pressure does not equal the commanded low and reverse/4-5-6 clutch pressure for 10.5 seconds.

P0970

The TCM detects an internal low voltage electrical malfunction of the clutch PC solenoid control circuit for 300 milliseconds.

P0971

The TCM detects an internal high voltage electrical malfunction of the clutch PC solenoid control circuit for 300 milliseconds.

Action Taken When the DTC Sets

P0969

    • DTC P0969 is a Type C DTC.
    • The TCM freezes transmission adaptive functions.

P0970 and P0971

    • DTCs P0970 and P0971 are Type A DTCs.
    • The TCM defaults the transmission to a limited shift pattern utilizing 2 forward gears and reverse based on the default detected.
    • The TCM commands maximum line pressure.
    • The TCM freezes transmission adaptive functions.

Conditions for Clearing the DTC

    • DTC P0969 is a Type C DTC.
    • DTCs P0970 and P0971 are Type A DTCs.

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics

Description and Operation

    •  Transmission General Description
    •  Transmission Component and System Description
    •  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 Verification

  1. Ensure the transmission fluid temperature is between 50-80°C (122-176°F).
  2. Perform the Control Solenoid Valve and Transmission Control Module Assembly Cleaning procedure to dislodge debris and free up valves.
  3. Operate the vehicle in 2nd gear long enough to ensure at least a 3°C (5°F) rise in TCM temperature, then operate the vehicle in 4th gear for 5 seconds.
  4. Verify that the scan tool data parameter, Clutch PC 3 Sol. CKT Status, displays OK.
  5. If not the specified value, replace the control solenoid (w/body and TCM) valve assembly.
  6. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

       Important: Before replacing the TCM, perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection.

    • Refer to Control Module References for control solenoid (w/body and TCM) valve assembly replacement, setup, and programming.
    • Perform the Service Fast Learn Adapts following all transmission related repairs.
    • Perform the Control Solenoid Valve and Transmission Control Module Assembly Cleaning procedure.