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 Descriptor

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

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

DTC P0971: 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

Typical Scan Tool Data

Clutch PC Solenoid 3

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

PC 3 Sol. CKT Status

OK

Open/Short to Volts

Short to GND

Open/Short to Volts

Circuit/System Description

The clutch pressure control (PC) solenoid 3 is part of the control solenoid (w/body and TCM) valve assembly and is not serviced separately. The transmission control module (TCM) supplies 12 volts to the clutch PC solenoid 3 on the high side driver 1 circuit. The TCM controls the PC solenoid 3 through the clutch PC solenoid 3 control circuit. The normally high clutch PC solenoid 3 controls fluid to the hybrid low, 1-2 and the 4th clutch assemblies when commanded ON and exhausts fluid when commanded OFF. The clutch PC solenoid 3 regulates the transmission fluid pressure to the hybrid low, 1-2 and the 4th clutch assemblies.

Conditions for Running the DTC

    • The engine run time is greater than 5 seconds.
    • The vehicle speed is less than 200 km/h (124 mph) for 5 seconds.
    • The system voltage is 11-18 volts.

Conditions for Setting the DTC

P0969

The TCM detects an internal electrical performance malfunction of the clutch PC solenoid control circuit when the actual hybrid low, 1-2 and the 4th clutch pressure does not equal the commanded hybrid low, 1-2 and 4th clutch pressure for 300 milliseconds.

P0970

The TCM detects an internal low voltage electrical malfunction of the clutch PC solenoid control circuit for 500 milliseconds.

P0971

The TCM detects an internal high voltage electrical malfunction of the clutch PC solenoid control circuit for 500 milliseconds.

Action Taken When the DTC Sets

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

Diagnostic Aids

When attempting to set solenoid electrical DTCs, ensure the TCM is warmed up and the transmission is operated 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

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Circuit/System Verification

Perform the following procedure to place the control solenoid (w/body and TCM) valve assembly under the optimal conditions to test solenoid electrical DTCs.

  1. Ensure the transmission fluid temperature is between 50-80°C (122-176°F).
  2. Operate the vehicle long enough to ensure at least a 3°C (5°F) rise in TCM substrate temperature, then operate the vehicle in 4th gear for 5 seconds.
  3. If the DTC resets, go to Circuit/System Testing.

Circuit/System Testing

The scan tool data parameter Clutch PC 3 Sol. CKT Status normally displays OK.

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, replace the control solenoid (w/body and TCM) valve assembly.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for control solenoid (w/body and TCM) valve assembly replacement, setup, and programming.