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 P1831: Pressure Control (PC)/Shift Lock Solenoid Control Circuit Low Voltage
DTC P1832: Pressure Control (PC)/Shift Lock Solenoid Control Circuit High Voltage

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage
--- | --- | --- | ---
High Side Driver 1 | P1831 | P1831 | P1832

### Circuit/System Description

The transmission control module (TCM) provides voltage to the pressure control solenoid, the shift solenoids, and the TCC PWM solenoid through two separate solid-state devices called high side drivers, called HSD1 and HSD2. HSD1 provides electrical power to the pressure control solenoid. HSD2 provides power to the shift solenoids. A normal function of the TCM is to run tests on each driver to ensure that it is functioning properly.

### Conditions for Running the DTC

#### P1831

The engine run time is greater than 5 seconds.

#### P1832

The ignition is ON.

### Conditions for Setting the DTC

#### P1831

The TCM detects a short to ground on the HSD1 circuit when the HSD1 is commanded ON.

#### P1832

The TCM detects greater than 6.4 volts at the HSD1 terminal prior to commanding the HSD1 ON.

### Action Taken When the DTC Sets

• | DTC P1831 and P1832 are Type C DTCs.

• | The TCM commands HSD1 OFF.

• | The TCM commands maximum line pressure.

• | The TCM freezes transmission adaptive functions.

• | SERVICE VEHICLE SOON displays on the driver information center (DIC).

### Conditions for Clearing the DTC

DTC P1831 and P1832 are Type C DTCs.

### Diagnostic Aids

1. Electrical Faults P1831 and P1832 only set on the PC Solenoid Valve High Control side (HSD1) of the PC Solenoid Valve. Electrical faults on the PC Solenoid Valve Low Control side (ground side) of the shift solenoids will set P0748.
2. An open on the PC Solenoid Valve High Control side (HSD1) of the PC Solenoid Valve will set P0748.

### Reference Information

#### Schematic Reference

Automatic Transmission Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Transmission General Description

#### 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

Transmission Control Module Scan Tool Information

#### Special Tools

• | J 35616 GM Terminal Test Kit

• | J 45681 Jumper Harness

### Circuit/System Verification

Ignition ON, engine OFF. With a scan tool, observe the High Side Driver 1 parameter status for:

• | Short to Ground

• | Open

• | Short to Volts

### Circuit/System Testing

1. Ignition OFF, disconnect the X121 harness connector.
2. Ignition ON, Engine OFF. Test for 4.0-6.4 volts between the Pressure Control (PC) Solenoid Valve High Control circuit terminal 13 and a good ground.

⇒ | If less than the specified value, test the PC Solenoid Valve High Control circuit for a short to ground or an open/high resistance. If circuits test normal, replace the TCM.

⇒ | If greater than the specified value, test the PC Solenoid Valve High Control circuit for a short to voltage. If circuits test normal, replace the TCM.

3. Install the J 45681 harness on the transmission pass-thru connector.
4. Using the brown J35616-6 test probes from the most current J 35616 kit , test for 3.5-5.5 ohms between the PC Solenoid Valve High Control circuit, terminal 13, and the PC Solenoid Valve Low Control circuit, terminal 8.

⇒ | If less than the specified value, test the PC Solenoid High Control circuit and the PC Solenoid Low Control circuit for a short together condition. If circuits test normal, replace the PC Solenoid Valve.

⇒ | If greater than the specified value, test the PC Solenoid Valve High Control circuit and the PC Solenoid Low Control circuit for an open. If circuits test normal, replace the PC Solenoid Valve.

5. Test for greater than 10 K ohms between the PC Solenoid High Control circuit, terminal 13, and all other circuits of the J 45681 harness , except the PC Solenoid Low Control circuit, terminal 8.

⇒ | If less than the specified value, the affected circuits are shorted together. Replace the transmissions internal wire harness.

6. Test for the greater than 10 K ohms between the PC Solenoid Low Control circuit, terminal 8, and all other circuits of the J 45681 harness , except the PC Solenoid High Control circuit, terminal 13.
7. Test for greater than 50 K ohms from the PC Solenoid High Control circuit, terminal 13, and the PC Solenoid Low Control circuit, terminal 8, to the transmission case.

⇒ | If less than the specified value, test the affected circuit for a short to the transmission case. If both circuits test normal, replace the PC Solenoid Valve.

### Component Testing

1. Ignition OFF, disconnect the X121 harness connector. Install the J 45681 harness on the transmission pass-thru connector.
2. Using the brown J35616-4 test probes form the most current J 35616 kit , test for 3.5-5.5 ohms between the PC Solenoid Valve High Control circuit, terminal 13, and the PC Solenoid Valve Low Control circuit, terminal 8.

⇒ | If less than the specified value, test the PC Solenoid Valve High Control circuit and the PC Solenoid Low Control circuit for a short together condition. If circuits test normal, replace the PC Solenoid Valve.

⇒ | If greater than the specified value, test the PC Solenoid Valve High Control circuit and the PC Solenoid Low circuit for an open. If circuits test normal, replace the PC Solenoid Valve.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• | Pressure Control Solenoid Valve Replacement

• | Transmission Internal Electrical Harness Replacement

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