ABS failure, no codes stored

[James P. Bohney]

1995 P71 Crown Vic. When the engine is started the ABS light comes on and then goes out signifying all is well. Then at about 18 mph the light comes back on and stays on. The ABS does not function. I have replaced the front sensors due to some cracks in the insulation. Still no luck. What could cause such a failure and store no codes readable by a hand held obd II?

[ModMech]

No common OBD-II scanner can access ABS codes, there are a FEW that can, but nothing you can buy at your local store or tool dealer.

ABS codes are accessed thru the OBD-II connector, but are on a different protocol than engine and trans codes, so you need a special scan tool to retrieve theose codes.

[James P. Bohney]

Originally Posted by ModMech

No common OBD-II scanner can access ABS codes, there are a FEW that can, but nothing you can buy at your local store or tool dealer.

ABS codes are accessed thru the OBD-II connector, but are on a different protocol than engine and trans codes, so you need a special scan tool to retrieve theose codes.

I took the car to an indy mechanic who used a hand held tool through the obd II port under the drivers dash. I watched him search for ABS codes. "no codes to retrieve" was the message. With the key stil on but engine off, we unplugged the two wire connector to the abs pump and rescanned. We got a code that stated "pump circuit failure". That code was then cleared. The car was test driven and again the abs light returned at about 15-18 mph, and again the message "on codes to retrieve"