C1225

DTC C1225 LF Excessive Wheel Speed Variation:

Wheel Speed Sensor Schematic:

CIRCUIT DESCRIPTION
The speed sensor used on this vehicle is a single point magnetic pickup. This sensor produces an AC signal that the EBCM/EBTCM uses the frequency from to calculate the wheel speed.

CONDITION FOR SETTING THE DTC
- The DTC can be set anytime the brake is not depressed and no wheel speed sensor hardware DTC(s) are present, and the EBCM/EBTCM sees a wheel speed variation of more than 14 Km/h (9 mph) for 2.5 seconds.

ACTION TAKEN WHEN THE DTC SETS
- A malfunction DTC is stored, ABS/TCS is disabled and the "ABS" and "TRACTION OFF" Indicator lamps are turned "ON."

CONDITIONS FOR CLEARING DTC
- Condition for DTC is no longer present and scan tool clear DTC function is used.
- 50 ignition cycles have passed with no DTC(s) detected.

DIAGNOSTIC AIDS
- It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
- An intermittent malfunction can be caused by poor connections, broken insulation, or a wire that is broken inside the insulation.

TEST DESCRIPTION
The numbers below refer to step numbers on the diagnostic table.
3. Checks the resistance of the WSS.
5. Checks if the WSS CKTs are shorted together.