ABS Light On

Duncan Thomson duncan at systemcontrols.co.nz
Tue Jul 3 19:32:51 EDT 2007


Yep, diff lock is the problem. ABS sounds to be working fine. Should 
disable, and light comes on if diff is locked.
If it's like my '88 90Q then the diff lock has an electronic switch (may 
still be pneumatically driven). So I would check for a loose wire at the 
switch, or break in the loom.

Does the diff lock ever disengage? If so, does the ABS return to normal? 
If so, then points to switch problem.

If diff lock is always on, then you'll need to check the actuator on the 
diff, make sure it moves freely, check connections / position sensor etc.

You could disconnect the actuator and manually move it to the unlocked 
position and see if that helps...

Duncan

-----
Kneale Brownson wrote:
> Isn't there a vacuum element to the diffy locks?  Don't see how a vacuum would be applied without throwing a switch but??????
>
> Andrew Duane <aduane at juniper.net> wrote:  It's likely the other way around. Locking the rear diff disables ABS, so
> there may be something messing with your diff lock.
>   



More information about the quattro mailing list