Antilock Brake System - Hybrid (HP5)
DTC C0110, C12E0, C12E8, or C12E9
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview)provides an overview of each diagnostic category.
DTC Descriptors
DTC C0110 00
- Pump Motor Circuit
DTC C0110 61
- Pump Motor Circuit Actuator Stuck
DTC C12E0
- ABS Pump Motor Performance
DTC C12E8
- ABS Pump Motor Stuck
DTC C12E9
- ABS Pump Motor Stuck On
Circuit/System Description
The pump motor is an integral part of the brake pressure modulator valve (BPMV), while the pump motor relay is integral to the electronic brake control module (EBCM). The pump motor relay is not engaged during normal system operation. When the antilock brake system (ABS) or traction control system (TCS) operation is required the EBCM activates the pump motor relay and turns the pump motor ON.
Conditions for Running the DTC
* Ignition ON.
* Ignition voltage is greater than 10 V.
* The system enable relay is ON.
* The pump motor has been commanded ON, OFF and ON again.
Conditions for Setting the DTC
* The EBCM detects a short to ground or an open/high resistance on the B+ circuit.
* The EBCM detects an open/high resistance on the ground circuit.
* The EBCM detects the pump motor runs continuously.
* The EBCM detects the pump motor is binding or stalled.
Action Taken When the DTC Sets
* The EBCM disables the ABS/traction control system (TCS)/vehicle stability enhancement system (VSES) for the duration of the ignition cycle.
* The ABS indicator illuminates.
* The red Brake indicator illuminates.
* The Stability Control indicator illuminates.
* The driver information center (DIC) displays All Wheel Drive OFF, Service StabiliTrak and Service Traction Control messages.
Conditions for Clearing the DTC
* The condition for the DTC is no longer present and the ECE 13 response is completed by driving the vehicle at speeds greater than 15 km/h (10 mph) to complete the self test, and the EBCM will turn off the ABS indicator.
* The EBCM clears the history DTC when a current DTC is not detected in 40 consecutive drive cycles.
Diagnostic Aids
* Find out from the customer the conditions under which the DTC was set. This information may help duplicate the failure like the specific number of brake pedal applies in a row prior to the fault set.
* Check for hydraulic leaks, air in the brake system or an improper brake bleed.
Reference Information
Schematic Reference
Antilock Brake System Schematics (2 Mode Hybrid) (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
ABS Description and Operation (Antilock Brake System - Hybrid)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning)for scan tool information
Circuit/System Verification
1. Ignition ON, perform the pump motor test with a scan tool and listen/feel the pump motor turn ON and OFF.
• If the pump motor does not turn ON and OFF, refer to Circuit/System Testing.
2. Start the engine and allow it to idle.
3. Place the transmission in the PARK position.
Note: To ensure the complete brake modulator and high pressure accumulator (HPA) pressure relief procedure is allowed to occur; the brake controller must see one brake pedal apply with the engine running followed by a proper shutdown without applying the brake pedal.
4. Apply and release the brake pedal.
Note: The ignition must transition to the OFF position without pausing at ACCESSORY and without applying the brake pedal. This ensures that the brake modulator and HPA pressure relief occurs.
5. Ignition OFF, without pausing at ACCESSORY, and without applying the brake pedal.
6. Remove the ignition key and wait 3 minutes until the brake modulator and HPA pressure relief is complete.
7. While observing the scan tool EBCM Accum. Pressure Sensor parameter, turn the ignition ON. Measure and record the time it takes for the pressure to reach 18,000 kPa (2,600 psi).
• If less than 30 seconds, the pump motor is good, refer to Brake Hydraulic and Assist System Diagnosis (Two-mode Hybrid) (Component Tests and General Diagnostics).
• If greater than 30 seconds, replace brake pressure modulator valve (BPMV) assembly.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the EBCM.
2. Test for less than 1 ohm between the ground circuits listed below and ground:
* Terminal 13
* Terminal 38
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify that a test lamp illuminates between the B+ circuits listed below and ground:
* Terminal 25
* Terminal 1
• 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, replace the BPMV.
4. If all circuits test normal, replace the BPMV and verify DTC does not reset. If the DTC resets replace the EBCM.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Brake Pressure Modulator Valve Replacement (Service and Repair)
* Control Module References (Programming and Relearning)for EBCM replacement, setup, and programming