Scantool ABS Help - 1990 C4
 

Does anyone know why I might have faults on my ABS system that do not display on Scantool?

I previously had a G-sensor issue that was displayed properly, and I fixed it, and fault is gone.

Now I get my ABS and traction lights on after about 30 seconds of driving. No 'gong', just the two warning lights.

When I turn the car off and scan there is no fault displayed, and when I run scantool while I'm driving, it won't connect to the ABS sytem. I can only connect the ABS feature when the engine is off. :confused:

Anyone know what might be going on?

Solved.

I let the brake fluid get a bit low when I bled the ABS...I bypassed the low fluid sensor and the problem is gone.

So, it appears that low brake fluid is not displayed immediately, and it does not have a stored ABS fault assigned.

Still not sure why I can't scan and drive, but that's a problem for another day.

Invariably the two biggest culprits for C4 ABS/PDAS warning lights are low fluid in the reservoir and low battery voltage. Every instance I've had of those lights illuminating has been down to one of those two reasons.

Neil

how did you bypass the brake fluid sensor?

I taped the float into the upper position...