For 1990-2009 cars

### 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

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
PC Solenoid High Control | P0961 | P0961 | P0961 | P0961
PC Solenoid Low Control | P0961 | P0961 | P0961 | P0961

### Typical Scan Tool Data

#### Line Pressure Control (PC) Solenoid Parameter Data

Circuit | Normal | Short to Ground | Open/High Resistance | Short to Voltage
--- | --- | --- | --- | ---
Operating Conditions: Engine running in Park, normal operating temperature Parameter Normal Range: 0.02-1.10 amps
PC Sol. Actual Current | 0.02-1.10 amps | Less than 0.02 amps | Less than 0.02 amps | Less than 0.02 amps
PC Sol. Ref. Current | 0.02-1.10 amps | Less than 0.02 amps | Less than 0.02 amps | Less than 0.02 amps

### Circuit/System Description

The pressure control (PC) solenoid valve is located in the valve body. The PC solenoid valve controls transmission line pressure based on current flow through the windings. The transmission control module (TCM) determines desired line pressure based on throttle position and other inputs. The TCM then varies the duty cycle on the high side of the PC solenoid valve to control current flow to the solenoid. Current is controlled from about 0.02 amps for maximum line pressure to 1.1 amps for minimum line pressure. The TCM monitors the actual current to the solenoid.

### Conditions for Running the DTC

• | The PC solenoid valve is enabled.

• | The engine is running.

### Conditions for Setting the DTC

The PC solenoid duty cycle is outside the range of 0.5-95 percent for 2 seconds.

### Action Taken When the DTC Sets

• | DTC P0961 is a Type C DTC.

• | The TCM commands maximum line pressure.

• | The TCM freezes transmission adaptive functions.

### Conditions for Clearing the DTC

DTC P0961 is a Type C DTC.

### Reference Information

#### Schematic Reference

Automatic Transmission Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Electronic Component Description for automatic transmission pressure control solenoid valve information

#### 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

#### Special Tools

J 44152 Jumper Harness (20 pins)

### Circuit/System Verification

Start and idle the engine. Using the scan tool, select PC Solenoid under the Transmission Output Controls. With the scan tool, command several values of solenoid reference current from 0.1 amp through 1.1 amps and observe the PC Sol. Actual Current and the PC Sol. Ref. Current. The PC Sol. Actual Current should not vary from the PC Sol. Ref. Current by more than 0.16 amps.

### Circuit/System Testing

Important: Additional DTCs may set when disconnecting the automatic transmission inline 20-way connector.

1. Disconnect the AT inline 20-way connector. Install the J 44152 on the transmission side on the connector. Using a terminal test kit , measure the resistance between the PC solenoid high control circuit terminal C and the PC solenoid low control circuit terminal D. The resistance should be between 3-7 ohms.

⇒ | If the resistance is greater than 7 ohms, test the PC solenoid high control circuit or the PC solenoid low control circuit for an open or a faulty PC solenoid valve.

⇒ | If the resistance is less than 3 ohms, test for the PC solenoid high control circuit and the PC solenoid low control circuit shorted together of a faulty PC solenoid valve.

2. Measure the resistance between the PC solenoid high control circuit terminal C and the transmission case. Measure the resistance between the PC solenoid low control circuit terminal D and the transmission case. The resistance should be greater than 10K ohms.

⇒ | If the resistance is less than 10K ohms, replace the internal transmission wiring harness assembly.

3. Measure the resistance between the PC solenoid high control circuit terminal C and all other circuits of the J 44152 except the PC solenoid low control circuit. Measure the resistance between the PC solenoid low control circuit and all other circuits of the J 44152 except the PC solenoid high control circuit. The resistance should be greater than 10K ohms.

⇒ | If the resistance is less than 10K ohms, replace the internal transmission wiring harness assembly.

4. Remove the J 44152 from the transmission side and install on the engine side of the harness. Disconnect the TCM connector. Using a terminal test kit , measure the resistance of the PC solenoid high control circuit terminal 40 between the TCM connector and the AT inline 20-way connector terminal C. Measure the resistance of the PC solenoid low control circuit terminal 17 between the TCM connector and the AT inline 20-way connector terminal D. The resistance should be less than 10 ohms for each circuit.

⇒ | If the value is greater than 10 ohms, repair the open in the affected circuit.

5. Measure the resistance between the PC solenoid high control circuit terminal 40 and ground. Measure the resistance between the PC solenoid low control circuit terminal 17 and ground. The resistance for each circuit should be greater than 10K ohms.

⇒ | If the value is less than 10K ohms, repair the short to ground in the affected circuit.

6. Reconnect the TCM connector. Turn ON the ignition with the engine OFF. Test the PC solenoid high control circuit and the PC solenoid low control circuit for a short to voltage.

⇒ | If a short to voltage condition is found, repair as necessary.

⇒ | If all circuits/connections test normal, test or replace the PC solenoid valve.

7. If all circuits/connections test normal, replace the TCM.

### Component Testing

Verify the PC solenoid valve resistance is between 3-7 ohms.

⇒ | If the resistance is not within the specified range, replace the PC solenoid valve.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• | Wiring Harness Replacement

• | Pressure Control Solenoid Valve Replacement

• | Control Module References for TCM replacement, setup, and programming.