DTC C1254: Rear Abs Channel In Release Too Long

1. Perform diagnostic system check. See DIAGNOSTIC SYSTEM CHECK. After performing diagnostic system check, go to next step.
2. Turn ignition on, with engine off. Install scan tool. Using scan tool, display DTCs. If any wheel speed sensor DTCs set as current, go to appropriate DTC. If no wheel speed sensor DTCs are set as current, go to next step.
3. Using scan tool, select DATA LIST. Test drive vehicle during a steady 35 MPH to zero MPH deceleration while monitoring all wheel speed sensor speeds. If any wheel speed sensors indicate erratic or intermittent operation, go to DTC C1225, C1226, C1227 or C1228. If no wheel speed sensor indicates erratic or intermittent operation, go to next step.
4. Turn ignition on, with engine off. Raise and support vehicle so that rear wheels are off ground. Spin each rear wheel by hand. If rear wheels spin freely by hand, go to next step. If rear wheel do not spin by hand, go to step 11)  .
5. Turn ignition on, with engine off. Using scan tool, select MISC TESTS, and then select MANUAL CONTROL. Using scan tool, select rear ABS MOTOR APPLY, and apply rear ABS motor. Apply firm pressure on brake pedal. Spin each rear wheel by hand. If rear wheels spin freely by hand, go to next step. If rear wheel do not spin by hand, go to step 12)  .
6. Maintain firm pressure on brake pedal. Using scan tool, select rear ABS MOTOR RELEASE, and release rear ABS motor. Spin each rear wheel by hand. If rear wheels spin freely by hand, go to next step. If rear wheel do not spin by hand, go to step 9)  .
7. Using scan tool, perform GEAR TENSION RELIEF. Turn ignition off. Separate modulator from motor pack. Reconnect ABS modulator/motor pack assembly connector if disconnected. Turn ignition on, with engine off. Using scan tool, perform ABS motor pack motor test. If all 3 motor pack gears (small gears) spin freely, go to next step. If all 3 motor pack gears (small gears) do not spin freely, go to step 10)  .
8. Replace modulator.
9. Repaired crossed rear motor high circuit or rear motor low circuit to rear motor pack.
10. Replace motor pack.
11. Repair source of resistance in base brake system. See appropriate DISC & DRUM article.
12. Malfunction is not currently present. An intermittent may be caused by a mechanical system component sticking, binding, or slipping. Frequency of malfunction can be determined by using enhanced diagnostic function of scan tool. Using scan tool, perform hydraulic test to ensure proper brake system function.

Check for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wiring connections, or damaged wiring harness. After diagnosis is complete, clear DTCs and test drive vehicle for 3 drive cycles to verify DTC does not reset. Drive cycle consists of starting vehicle, driving vehicle faster than 10 MPH, stopping vehicle, and then turning ignition off.