C1251

DTC C1251 (1 Of 3):

DTC C1251 (2 Of 3):

DTC C1251 (3 Of 3):

CIRCUIT DESCRIPTION
This DTC is designed to detect a stripped nut or gear assembly during initialization. During the homing sequence, the piston should reach the top of the bore resulting in a stalled ABS motor. If this does not occur, the ABS motor must be spinning with little or no resistance, indicating a nut/screw or gear malfunction.

CONDITIONS FOR SETTING THE DTC
DTC C1251 can be set during initialization. If the feedback current is less than the command current for a specified period of time, a malfunction exists.

ACTION TAKEN WHEN THE DTC SETS
A malfunction DTC is stored, ABS is disabled, the amber ABS warning indicator and the red BRAKE warning indicator are turned on.

DIAGNOSTIC AIDS
An intermittent malfunction in this DTC may result from a mechanical part of the system that sticks, binds, or slips. The frequency of the malfunction can be checked by using the enhanced diagnostic function of the scan tool. If the DTC only occurs once and DTC C1264 also occurs, refer to DTC C1264. If intermittent and enhanced diagnostics show this DTC occurs during ABS, refer to DTC C1264. Depending on the frequency of the malfunction, a physical inspection of the mechanical parts suspected may be necessary.

NOTE: J 39200 test leads must be zeroed prior to making any resistance measurements.

After diagnosis is complete, clear the DTCs and test drive the vehicle for three drive cycles to verify that the DTC does not reset. A drive cycle consists of starting the vehicle, driving the vehicle over 16 km/h (10 mph), stopping and then turning the ignition off.