Please forgive me if there is a thread on this topic; I didn't see one when I reviewed the forum topics. I have a 1997 Q45T. Suddenly the ABS/TCS lights all come on as soon as the car starts moving. I am assuming it is one of the wheel speed sensors. But before I start a trail and error method of sensor replacements, I thought I'd check here to see if there is a consistent pattern amongst Q45's. Is it likely a wheel speed sensor, and if so, is any particular sensor a more likely culprit? It's my understanding that the front sensors are different than the rear sensors. Could it be something other than a wheel speed sensor?
Thank you very much.
ABS/TCS Indicator Lights
Re: ABS/TCS Indicator Lights
I don't know about the wheel sensors, but when I work on my engine and sometimes have to start the car without the MAF connected, the ABS/TCS light....as well as the check engine light, will come on.
Are you getting a check engine light?
If so, get a code reader and report back as to what codes you're throwing.
Are you getting a check engine light?
If so, get a code reader and report back as to what codes you're throwing.
Re: ABS/TCS Indicator Lights
No check engine light coming on. Only the ABS/TCS off/Slip lights come on. All of them, every time. In park, I can make the TCS off light come on by pushing my TCS button, so at least I know the lights can work independently.
Re: ABS/TCS Indicator Lights
if the tcs system is any thing like the 90-96 models it means your tcs actuator has gone bad. i had this happen in my last q which was a 95. you can flush the system with dot3 you may want to check to see if your low on fluid. keep in mind doing a flush on the tcs system may not make a difference but it may help. do you hear a noise when you first start the car?
Re: ABS/TCS Indicator Lights
I don't hear any noise. And the brake fluid level was the first thing I checked. It is full.
Re: ABS/TCS Indicator Lights
the actuator can still be bad you should have the codes checked just on principle there can be codes with out a check engine light
Re: ABS/TCS Indicator Lights
and as far as the dot3 goes its the dot3 in the traction control reservoir you need to check not your brake cylinder reservoir
Re: ABS/TCS Indicator Lights
Oh, thanks! I didn't realize there were 2 reservoirs. As a side note, I had to replace the battery, so there was no battery for several hrs one day. I don't know if that was sufficient to "reset" any codes, but it had no effect. The indicator lights always only come on once the vehicle is placed in motion. I priced a wheel sensor, in case I wanted to do a trial and error test. The front right and left sensors are different, with different prices. The rears are the same, but at much more cost than the front. My Mercedes mechanic is moving to Infinity in Jan He says he'll have access to the scan tools to correctly diagnose it, if I can live with it until then.