Diagnostic Instructions
DTC Descriptor
DTC C0820: Device Ground 1 Circuit Voltage Above Threshold
Circuit/System Description
The electronic brake control module (EBCM) monitors the voltage level of the EBCM case. If the voltage level is too high, damage may result in the system. When the EBCM detects a high voltage condition, the EBCM turns OFF the system relay which removes
battery voltage from the solenoid valves and pump motor.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
The case voltage is greater than 2 volts for 0.1 second.
Action Taken When the DTC Sets
If equipped, the following actions occur:
| • | The EBCM disables the ABS/ACC/VSES for the duration of the ignition cycle. |
| • | The DRP and TCS are degraded. |
| • | The ABS indicator illuminates. |
| • | The Traction Control indicator illuminates. |
| • | The red Brake warning indicator illuminates. |
Conditions for Clearing the DTC
| • | The condition for the DTC is no longer present. |
| • | The electronic brake control module (EBCM) automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles. |
Diagnostic Aids
Possible causes of this DTC are the following conditions:
| • | Internal short in the pump motor. |
| • | External battery supply shorted to case. |
| • | Internal EBCM battery supply shorted to case. |
The pump motor is integral to the BPMV. The pump motor is not serviceable.
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
Scan Tool Reference
Control Module References
for Scan Tool Information
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the EBCM.
- Test for less than 1.0 ohm of resistance between the ground circuit terminal E and ground.
| ⇒ | If not within the specified range, test the ground circuit for an open/high resistance. |
- Disconnect the pump motor.
- Test for infinite resistance between the pump motor terminal and ground.
| ⇒ | If not the specified value, replace the BPMV. |
| ⇒ | If all circuits test normal, replace the EBCM. |
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
