TCS/ABS/SLIP Light question

[scout]

Hey guys,
Just bought a 98 Q45 after years of wanting one.

Guy I bought it from took excellent care of car and mechanic that checked said it was one of the best kept Qs he has seen.

Car has one issue, TCS/ABS/SLIP lights come on after 20-30 mins of driving.

Had ABS relays replaced but that did not solve problem.

Making me nervous to drive with these systems disabled, any thoughts of what it could be?

Thanks.

[Infinitiexpert]

Try to get the TCS/ABS/SLIP code. When the light is ON you need to drive to the dealer or any shop with a scanner and have them check the ABS code. The ABS relay is the most common problem, but there are other items that can cause the light to come ON like the ABS sensor (s), tires, throttle motor, control unit.

[celfer1901]

i have the same problem it is always on, how much do they charge just to check the abs code?

[Nick_H]

Depending on the combination of lights -- even when all are on, it can also be two more things:

1: The knock sensors -- the VH41DE motor has eight knock sensors, and if any one (or multiple) is/are failing, then that will cause the lights to come on.

2: Believe it or not, a failing alternator will cause this scenario as well.

Both these two are among the things to fail on Q45s of that era -- I own two, a 1998 and a 2000 -- I know firsthand.

As people have posted on this thread before, get your service shop to scan the error codes on the OBD-II computer and that will give you a starting point -- the error code list is on this web site.

Best of luck, and keep us posted on what you find.

FYI -- the knock sensors are not cheap -- I had all 8 replaced at my dealer (#3 and #7 were failing) and it cost me about $850.

-Nick