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 Descriptors

DTC C0895 03: Device Voltage Below Threshold - PSCM

DTC C0895 11: Device Voltage Above Maximum Threshold - PSCM

DTC C0895 12: Device Voltage Below Minimum Threshold - PSCM

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

B+

C0895 00

C0895 00

--

--

Ground

--

C0895 00

--

--

Typical Scan Tool Data

Battery Voltage Signal - PSCM

Circuit

Short to Ground

Open

Short to Voltage

Operating Conditions: Ignition ON, Engine OFF.

Parameter Normal Value: 12.60 Volts

B+

0.00 Volts

0.00 Volts

12.60 Volts

Circuit/System Description

Voltage is supplied to the power steering control module (PSCM) by the battery positive (B+) voltage circuit. The PSCM monitors the supplied voltage to determine if it is within a valid operating range. Damage to components, and incorrect data may occur if the voltage is out of range. The PSCM disables all outputs, and sets DTC C0895 if high or low battery voltage is detected.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

Battery voltage is outside the normal range of 9.0-15.5 volts.

Action Taken When the DTC Sets

The PSCM disables all functionality.

Conditions for Clearing the DTC

    • A current DTC will clear when the PSCM receives battery voltage in the normal range of 9-15.5 volts.
    • A history DTC will clear if the condition does not return after 50 consecutive ignition cycles.

Diagnostic Aids

    • A high or low voltage value in multiple modules indicates a concern in the charging system.
    • Overcharging with a battery charger or jump starting can cause this DTC to set.

Reference Information

Schematic Reference

Power Steering Schematics

Connector End View Reference

Component Connector End Views

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 volts.
  2. If not within the specified range, refer to Charging System Test .
  3. Observe the scan tool PSCM Battery Voltage Signal 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 ohms between the ground circuit terminal 2 X1 and ground.
  3. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Verify that a test lamp illuminates between the B+ circuit terminal 1 X1 and ground.
  5. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  6. 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.