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 C0900 00: Device Voltage High - EBCM 12V

DTC C0900 07: Device Voltage High - EBCM 12V

DTC C12E2 00: Device Voltage High - EBCM 12V

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

12 V B+

C0899 00, C0899 03

C0899 00, C0899 03

C0900 00, C0900 07

--

Ground

--

C0899 00, C0899 03

--

--

Typical Scan Tool Data

Battery Voltage Signal - EBCM

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 EBCM if there is 0 Volts on the circuit.

Circuit/System Description

The electronic brake control module (EBCM) monitors the 12 V battery positive (B+) voltage. If the voltage level is too high, damage may result in the system. When a high voltage condition is detected the EBCM turns OFF the system relay which removes 12 V battery voltage from the solenoid valves and pump motor, and DTC C0900 sets.

Conditions for Running the DTC

Ignition is ON.

Conditions for Setting the DTC

The 12 V battery voltage is greater than 16 volts for 100 msec.

Action Taken When the DTC Sets

    • The traction control system (TCS) and vehicle stability enhancement system (VSES) are disabled for the duration of the ignition cycle.
    • The antilock brake system (ABS) is disabled if ignition voltage exceeds 19.5 V.
    • The stability system off and traction control off indicators turn ON.
    • The ABS indicator turns ON if voltage exceeds 19.5 V.

Conditions for Clearing the DTC

    • The DTC will pass when the battery voltage is less than 15.5 V for 100 msec.
    • The EBCM automatically clears a history DTC when a current DTC is not detected in 100 consecutive drive cycles.
    • The indicators and DIC messages turn OFF when the DTC is cleared, or on the next malfunction-free ignition cycle.

Diagnostic Aids

    • This DTC could be set by overcharging with a battery charger.
    • A high voltage DTC in multiple modules indicates a concern in the charging system.

Reference Information

Schematic Reference

Antilock Brake System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

ABS 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 12 V battery terminals. The voltage should be between 12.6-15.0 V.
  2. If not within the specified range, refer to Charging System Test.
  3. Observe the scan tool EBCM Battery Voltage parameter. The reading should be between 12.6-15.0 Volts.
  4. If greater than the specified range, replace the EBCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for EBCM replacement, setup, and programming.