PC6

NOTE: Step PC6 is optional, for additional information only.

- Drive vehicle and observe ABS warning light.

- Does ABS warning light come on during any of the following?
- When vehicle moves initially (light comes on at or near 6 mph)

- While driving under 25 mph

- While driving at or over 25 mph

- While in an anti-lock stop

YES -- At or near 6 mph, concern most likely found during pump check. Go to PC4. Verify pump diagnostic trouble code has been set. PC4

YES -- While driving under 25 mph, most likely cause is missing wheel speed sensor output. Go to PC4. PC4 Verify sensor diagnostic trouble code has been set.

YES -- While driving over 25 mph, most likely cause is an erratic wheel speed sensor output. Go to PC4. PC4 Verify sensor diagnostic trouble code has been set.

NO -- But vehicle has abnormal ABS or brake system operation. Go to symptom chart.

NO -- And no abnormal operation or symptoms detected. Go to PC4. PC4 Verify Code 16 (System OK) is present.