C0900

DTC C0899 or C0900

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

DTC Descriptor
DTC C0899 00
- Device Voltage Low - EBCM

DTC C0899 03
- Device Voltage Low - CCM

DTC C0900 00
- Device Voltage High - EBCM

Diagnostic Fault Information





Typical Scan Tool Data





Circuit/System Description

The following control modules monitor the battery voltage available for system operation. A high or low voltage condition prevents the system from operating properly.

* Electronic brake control module (EBCM)
* Rear differential clutch control module (CCM)

Conditions for Running the DTC

C0899 00 or C0900 00
* The ignition is ON.
* The vehicle speed is greater than 6 km/h (3.7 mph).

C0899 03

The ignition is ON.

Conditions for Setting the DTC

C0899 00

The EBCM detects that the battery voltage is less than 9.3 V.

C0899 03

The rear differential clutch control module detects that the system voltage is less than 8 V for 30 seconds.

C0900 00

The EBCM detects that the battery voltage is greater than 16.8 V.

Action Taken When the DTC Sets

C0899 00
* The antilock brake system (ABS), traction control system (TCS), and vehicle stability enhancement system (VSES) are disabled.
* The dynamic rear proportioning (DRP) is disabled, if the battery voltage is less than 6.9 volts.
* The ABS and traction control indicators turn ON.
* The BRAKE indicator turns ON, if the battery voltage is less than 6.9 volts.
* The driver information center (DIC) displays the TRACTION CONTROL OFF message 1 time.
* The DIC displays the SERVICE STABILITRAK and SERVICE TRACTION CONTROL messages.

C0899 03
* A DIC message and/or a warning may be displayed.
* Temporarily disables AWD mode.

C0900 00
* The ABS, DRP, TCS, and VSES are disabled.
* The ABS, BRAKE, and traction control indicators turn ON.
* The DIC displays the TRACTION CONTROL OFF message 1 time.
* The DIC displays the SERVICE STABILITRAK and SERVICE TRACTION CONTROL messages.

Conditions for Clearing the DTC

C0899 00 or C0900 00
* The DTC will pass when the condition for setting the DTC is no longer present.
* The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.
* The ABS, BRAKE, and traction control indicators turn OFF when the DTC passes, or when the battery voltage is greater than 9.5 volts.

C0899 03

The system voltage returns above 8 V for 1 second.

Diagnostic Aids

* A high or low voltage DTC in multiple modules indicates a concern in the charging system.
* DTC C0900 could be set by overcharging with a battery charger or jump starting.
* The ABS, BRAKE, and traction control indicators may turn ON without any DTCs set, if the EBCM detects that the battery voltage is less than 9.5 V, and the vehicle speed is less than 6 km/h (3.7 mph).

Reference Information
Schematic Reference

* Antilock Brake System Schematics (Electrical Diagrams)
* All-Wheel Drive Schematics (Electrical Diagrams)

Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

* ABS Description and Operation (Description and Operation)
* Rear Drive Axle Description and Operation (Description and Operation)

Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Programming and Relearning (Programming and Relearning) 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 12.6-15.0 V.

• If not within the specified range, refer to Charging System Test (Acadia or Enclave) ().

2. Observe the appropriate module scan tool Battery Voltage Signal parameter. The reading should be between 12.6-15.0 V.

Circuit/System Testing

C0899 00 or C0900 00
1. Ignition OFF, disconnect the harness connector at the EBCM.
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 terminals listed below and ground.

* Terminal 13
* Terminal 38

• 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 terminals listed below and ground.

* Terminal 1
* Terminal 25

• 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 EBCM.

C0899 03
1. Ignition OFF, disconnect the harness connector at the rear differential clutch control module.
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 3 X2 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 terminals listed below and ground.

* Terminal 5 X2
* Terminal 6 X2

• 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 rear differential clutch control module.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

Programming and Relearning (Programming and Relearning) for appropriate control module replacement, setup, and programming