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 P0961: Line Pressure Control (PC) Solenoid System Performance

DTC P0962: Line Pressure Control (PC) Solenoid Control Circuit Low Voltage

DTC P0963: Line Pressure Control (PC) Solenoid Control Circuit High Voltage

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Line PC Solenoid Control

P0962

P0963

P0963

P0961

Typical Scan Tool Data

Line PC Solenoid

Circuit

Short to Ground

Open

Short to Voltage

Operating Conditions: Engine running, normal operating temperature

Parameter Normal Range: OK

Line PC Sol. CKT Status

Short to GND

Open/Short to Volts

Open/Short to Volts

Circuit/System Description

The line pressure control (PC) solenoid is part of the control solenoid (w/body and TCM) valve assembly and is not serviced separately. The line PC solenoid regulates the transmission fluid line pressure when the engine is running. The transmission control module (TCM) varies the current to the normally high line PC solenoid valve from 0.1 amp for maximum line pressure, to 1.1 amps for minimum line pressure. This is accomplished by varying the current in order to obtain the desired line pressure in kPa (psi).

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.

P0961

DTC P0961 is not failed this ignition.

P0962

DTC P0962 is not failed this ignition.

P0963

DTC P0963 is not failed this ignition.

Conditions for Setting the DTC

P0961

The TCM detects an internal electrical performance malfunction of the line PC solenoid control circuit and the actual line pressure does not equal the commanded line pressure for 300 milliseconds.

P0962

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

P0963

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

Action Taken When the DTC Sets

DTC P0961

    • DTC P0961 is a Type B DTC.
    • The TCM freezes transmission adaptive functions.

DTC P0962

    • DTC P0962 is a Type A DTC.
    • The TCM defaults the transmission to 3rd gear.
    • The TCM commands maximum line pressure.
    • The TCM freezes transmission adaptive functions.

DTC P0963

    • DTC P0963 is a Type A DTC.
    • The TCM freezes transmission adaptive functions.

Conditions for Clearing the DTC

    • DTC P0961 is a Type B DTC.
    • DTCs P0962 and P0963 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 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

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 2nd gear long enough to ensure at least a 3°C (5°F) rise in TCM temperature, then operate the vehicle in Park for 5 seconds.
  3. Observe the scan tool data parameter Line PC Sol. 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 Module References for control solenoid (w/body and TCM) valve assembly replacement, setup, and programming.