This sounds like you have a control relay that is not working or you have a bad connection and the relay. Here is a guide to help you test the relay
Here is what the book says with the wiring and relay locations.
If the above fails, here are the diagnostics procedures:
DTC C0265 OR DTC C0266: EBCM RELAY CIRCUIT
1. Using scan tool, clear DTCs and perform ABS function test. If DTC C0266 sets, go to step 6. If DTC C0266 does not set, go to next step.
2. If DTC C0265 is also set, go to next step. If DTC C0265 is not set, problem is intermittent.
3. Turn ignition off. Disconnect EBCM harness connector containing the battery positive voltage circuit. Connect a test light between the battery positive voltage circuit and a good ground. If test light illuminates, go to step 5. If test light does not illuminate, go to next step.
4. Repair open in battery positive voltage circuit. After repairs, go to step 10.
5. Check for poor connections at EBCM harness connector. Repair as necessary. After repairs, go to step 10. If connections are okay, go to next step.
6. Separate EBCM from BPMV to gain access to pump motor harness connector. Disconnect ABS pump motor harness connector from EBCM. Using a DVOM, check resistance between ABS pump motor terminals. If resistance is 0.3-1.0 ohms, go to next step. If resistance is not 0.3-
1.0 ohms, go to step 9.
7. Check resistance between the high side of pump motor and a good ground. If resistance reading is infinite, go to step 9. If resistance reading is not infinite, go to next step.
8. Using scan tool, perform tire size calibration procedure and trim level calibration procedure (if applicable). Replace EBCM. After replacing EBCM, go to step 10.
9. Using scan tool, perform tire size calibration procedure and trim level calibration procedure (if applicable). Replace EBCM and BPMV. After replacing EBCM and BPMV, go to next step.
10. Using scan tool, clear DTCs. Operate vehicle at speeds greater than 4 MPH. Recheck DTCs. If DTC resets, go to step 1. If DTC does not reset, system is okay.
Check out the diagrams (Below). Please let us know what you find.
Images (Click to enlarge)
Monday, April 11th, 2011 AT 1:37 PM