New front rotors, calipers and pads, ABS lite persists

Rocket99 · Post by **Rocket99** » 12 Dec 2020, 06:47

Front L wheel began to have scraping sound. Neil nailed it, it was L caliper so now both fronts have new rotors, calipers and pads. These Volvo brakes are the nicest ones I've worked on, easy to swap out.

Just before I took it off the road and ordered those parts the ABS light came on and persists still now with fresh parts. I disconnected the battery thinking it may reset, no dice. My little blue driver code reader and reset did not clear the ABS dash light. Brakes are working fine though I'll do complete bleed since I only bled the fronts during the install.

Haynes states the ultimate horror: dealer only to clear that code.

The ABS sensor to the CV joint did not appear to be affected in any way.

Bingo! immediately after posting the above I took one more crack at clearing the ABS light , no go. Then on a short drive it went out. The Volvo dealer: a fate worse than death.

Post by **scot850** » 12 Dec 2020, 08:38

Well done on brake noise issue.

The ABS light can be caused by:

1) Bad ABS sensor/wire at a wheel or in the wire near to any wheel
2) A sensor ring on an axle being corroded or dirty preventing the sensor getting a consistent signal
3) A failing ABS module.

The first item can be tested by a resistance test on the wires and comparing them. There are resistance value ranges for these, but don't have that info to hand.

Neil.

Post by **erikv11** » 12 Dec 2020, 14:41

https://www.midwest-abs.com/1999-2000_S70.php

Check the troubleshooting link on the left side.

Post by **scot850** » 12 Dec 2020, 19:36

Thanks for adding the link erik

Neil.

Post by **abscate** » 13 Dec 2020, 03:04

On a 1999-2000, the m8 bolt holding the axle in place will code abs if it is not torqued correctly. It’s 14 mm head. Dont over torque

If you get ABS light after the short burp on first reaching 10-15 mph, the module and pump are probably ok, one of the wheels isn’t right, in my experience.

befarrer · Post by **befarrer** » 13 Dec 2020, 21:34

Also, if you were running the car with front wheels off the ground, so the wheels were spinning will confuse the ABS, it expects some sort of signal from the back, when it doesn't it sets a code for the rear wheel sensors. It resets after driving a bit, usually once getting up to 12mph or so and it sees all 4 sensors.