Diagnostic Instructions
DTC Descriptor
DTC C0116 04: Pump Motor Relay Circuit Open Circuit
Circuit/System Description
The electronic brake control module (EBCM) supplies ground to activate the antilock brake system (ABS) pump motor. An internal system relay in the EBCM supplies battery positive voltage to the pump motor when the ignition is turned ON. The EBCM monitors
pump motor feedback voltage after activation to detect a stalled or binding pump motor.
Conditions for Running the DTC
| • | Ignition voltage is greater than 8 volts. |
| • | The system enable relay is ON. |
| • | The pump motor has been commanded ON. |
Conditions for Setting the DTC
| • | Voltage across the pump terminals is less than 8 volts. |
| • | Voltage on the positive terminal of the pump is less than 9.25 volts. |
| • | The pump relay coil is not shorted to battery voltage or open. |
Action Taken When the DTC Sets
| • | The EBCM disables the ABS system. |
| • | The ABS indicator illuminates. |
| • | Dynamic rear proportion (DRP) function is degraded. |
Conditions for Clearing the DTC
| • | The condition for 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. |
Diagnostic Aids
The pump motor is integral to the brake pressure modulator valve (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 5 ohm of resistance between the ground circuit terminal E and ground.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
- Ignition ON, verify that a test lamp illuminates between the B+ circuit terminals A and B and ground.
| ⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test or replace the BPMV. |
- Ignition OFF, remove the EBCM from the BPMV.
- Inspect the EBCM to BPMV connector for no damage, corrosion, or presence of brake fluid.
| ⇒ | If connector corrosion or damage is evident, replace BPMV and/or EBCM as necessary. |
| ⇒ | If brake fluid is present, replace both BPMV and EBCM. |
- If all circuits test normal, replace the BPMV.
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
