DTC C0265 or C0266
Circuit Description
The ABS relay supplies battery voltage to 6 valve solenoids. The electronic brake control module (EBCM) microprocessor applies the grounds needed to activate each solenoid. The low side of each solenoid coil has a feedback circuit to the EBCM microprocessor. When a solenoid is commanded OFF, the feedback voltage is high. When a solenoid is commanded ON, the feedback voltage is low.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
- DTC C0265 EBCM Motor Relay Circuit
- DTC C0266 EBCM Motor Relay Circuit
Conditions for Running the DTC
- The ignition is ON.
- The vehicle speed is greater than 6 km/h (4 mph) .
Conditions for Setting the DTC
The EBCM detects an internal malfunction.
Action Taken When the DTC Sets
C0265
If equipped, the following actions occur:
- The EBCM disables the DRP/ABS.
- The ABS indicator turns ON.
- The brake warning indicator turns ON.
C0266
If equipped, the following actions occur:
- The EBCM disables the ABS.
- The ABS indicator turns ON.
Conditions for Clearing the DTC
The conditions for setting the DTC are no longer present and you use the scan tool Clear DTCs function.
Diagnostic Aids
Important: Whenever the EBCM is replaced for DTC C0265 or C0266, the ABS pump motor and motor circuitry must be tested for the proper resistance. Refer to steps 7 and 8 in the diagnostic table shown for testing procedures and resistance values.
C0265
Thoroughly inspect connections and circuitry that may cause an intermittent malfunction.
C0266
Replace the EBCM if DTC C0266 continues to set intermittently.
Since you've cleaned the ground, there may be a failure within the EBCM unit. It's not entirely surprising given its location gives it fairly high exposure to the elements, and road salt. The diagnostic procedure here states that examining the circuitry (by opening the EBCM case) may point you to an issue, and if you know your way around electronics it's worth a shot. If not, a new EBCM may be in your future.