Inspection And Verification: Notes

CAUTION: Diagnosis by substitution from a donor vehicle is NOT acceptable. Substitution of control modules does not guarantee confirmation of a fault, and may also cause additional faults in the vehicle being tested and/or the donor vehicle

Verify the customer concern
Confirm if the ABS warning light was illuminated, or still is
NOTE: An intermittent fault may allow the warning light to go off. This does not necessarily mean the fault is not present. Some warnings will appear to clear when the ignition is cycled. This is often because the warning has flagged as a result of one of the vehicle's on-board diagnostic routines having run to detect the fault. If the same routine is not run when the ignition status is set to ON , the warning will not re-flag until the routine does run

Visually inspect for obvious signs of damage and system integrity

VISUAL INSPECTION

MECHANICAL	ELECTRICAL
Brake fluid level Vacuum system Wheel speed sensor installation Wheel speed sensor air gap Magnetic pulse wheel(s) (damaged/contaminated) Steering angle sensor Yaw rate lateral acceleration sensor Incorrect wheel or tire size	Warning light operation Fuses Wheel speed sensors Connectors/Pins Harnesses Steering wheel rotation sensor Yaw rate lateral acceleration sensor Booster pressure sensor Hydraulic control unit

If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step
If the cause is not visually evident check for Diagnostic Trouble Codes (DTCs) and refer to the appropriate Diagnostic Trouble Code (DTC) Index information