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 Descriptors

DTC C0800 03: Control Module Power Circuit Low Voltage - PSCM
DTC C0800 07: Control Module Power Circuit High Voltage - PSCM
DTC C0800 11: Control Module Power Circuit High Input - PSCM

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
B+ | C0800 03 | C0800 03 | -- | --
Ground | -- | C0800 03 | -- | --

### Typical Scan Tool Data

#### Battery Voltage

Circuit | Short to Ground | Open | Short to Voltage
--- | --- | --- | ---
Operating Conditions: Ignition ON, engine OFF. Parameter Normal Value: 12.6 Volts
B+ | 0.0 Volts* | 0.0 Volts* | 12.6 Volts
*The scan tool will not communicate with the PSCM if there is 0 Volts on the circuit.

### Circuit/System Description

The power steering control module (PSCM) monitors the system voltage to make sure that the voltage stays within the proper range. Damage to components, and incorrect operation can occur when the voltage is out of range.

### Conditions for Running the DTC

The ignition is ON.

### Conditions for Setting the DTC

#### P0800 03

The PSCM detects that the battery voltage is less than 8.75 volts.

#### P0800 07

The PSCM detects that the battery voltage is greater than 16 volts.

#### P0800 11

The PSCM detects that the battery voltage is greater than 18 volts.

### Action Taken When the DTC Sets

• | The driver information center (DIC) displays the SERVICE POWER STEERING message.

• | Steering assist is reduced.

### Conditions for Clearing the DTC

• | The DTC will pass when the condition for setting the DTC is no longer present.

• | A history DTC will clear after 100 consecutive ignition cycles without failing the DTC.

### Diagnostic Aids

• | DTC C0800 could be set by overcharging with a battery charger or jump starting.

• | A high or low voltage DTC in multiple modules indicates a concern in the charging system.

### Reference Information

#### Schematic Reference

Power Steering Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

• | Power Steering System Description and Operation

• | Charging System Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

1. Engine running, accessories OFF, measure and record the battery voltage at the battery terminals. The voltage should be between 12.6 and 15.0 V.

⇒ | If not within the specified range, refer to Charging System Test.

2. Observe the scan tool Battery Voltage parameter. The reading should be between 12.6 and 15.0 Volts.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connectors at the PSCM.
2. Ignition OFF and scan tool disconnected, open and close the driver door, and wait 1 minute. Test for less than 5 Ω between the ground circuit terminal 10 X1 and ground.

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

3. Verify that a test lamp illuminates between the B+ circuit terminal 1 X1 and ground.

⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

4. If all circuits test normal, replace the PSCM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for PSCM replacement, setup, and programming