Slip & TCS Light won't go off!!

[jaysq]

Hey Guys, From reading all the other posts, the site is a great relief to us Q guys (mechanics know very little about the Q's wokings). My problem is that the Slip and TCS light will come on while driving. No specific time or reason, but it will stay on until I turn the car off. If I turn her back on the light will be gone but will return after driving for a while.Anything I should look for?Any help would be great!!

[PalmerWMD]

I am gonna move this to our online mechanic section.

Fred..

[elwesso]

Check the fuse...... I believe there is one under the hood, and one in the passenger compartment.......

[Q451990]

The relays for that system tend to freeze frequently... I don't have TCS, so I don't have any specific experience. Someone else should comment soon.

Heath

[mpoyner]

First things first: check to make sure that the wiring harness isn't unplugged for some reason. I just got my Q. The slip and TCS lights were on when I bought it and I almost bought the sensors, etc.

Just before I ordered them, I changed the oil and noticed something unplugged to the rear right under the hood (if facing the car from the front bumper).

Plugged it in and my TCS works perfectly. I have no idea why they unplugged it, but...

[jaysq]

Thanks for the suggestions, I tried looking for a connector but didn't fing anything specific. Where excatly is the tcs connector located? Near the brake fluid reservior, on the firewall... please help.

[mpoyner]

I'll have to look again. I just remember that if you're facing the car from the front, look toward the rear right of the engine compartment. Not as far as the firewall. A little before that.

[jaysq]

Thanks, I'll try again tonight. BTW its a '91 Q

[Rex]

I'll ask the dumb question - Are the front and back tires the same size?

[jaysq]

Stock 15"'s all around.

[elwesso]

We're talking about tire size...... IF their the stock 15s, they should all be something like 225/60r-15 or something like that.... Just go around and make sure they are all the same number.....

[jaysq]

215/60r 15 front and rear.

[Rex]

How much air pressure or tread depth difference would it take to make the computer think the rears are turning at a different of speed than the fronts?

(Now) Doubting this is it, but would be nice to know how much variance the computer needs to see before it thinks the rears are slipping.

[jaysq]

Mind you, i'm not doubting your question, I rather appreciate the help but wouldn't then the lights go out if I were at a stand still or parked? Which they don't.

[Rex]

Oh, I'm doubting it at this point

Also, didn't get the "on even if in park" from the previous posts. Maybe, this will mean something to the true guru's.

Good luck.

Does it slow the car/impact performance?

[jaysq]

Not that i'm aware of. When the lights come on I drive a little more cautiously than normal so I really couldn't tell. If anyone is listening, can heat from the brakes/rotor affect the slip & tcs sensors? Anything to check for?

[elwesso]

When both lights are on, it simply means it is disabled, with a malfunction...... Excess heat shouldnt be a problem, since they are on the diff. side, not the wheel side.........

Obviously youll want to check for loose connections and blown fuses...... The only TCS fuse I could locate was under the hood....... 20a fuse, top left hand side, there should be 3 fuses, and its the middle one....

If NG, Ill go over the section of the FSM for you, I dont have time right now.....

[aaronl]

95QA

OK I used the search and found this thread and didn't see a good answer. My problem is the same as Jay's. After driving for about 10 minutes the TCS off and Slip lights come on. They do not come back on after a restart until a few minutes of driving. I drove about a 100 miles and the problem didn't ocur. On the return trip after about 70 miles the lights came on. I stopped and restarted the car. no lights for about 5 minutes then on again. She drove the car today no lights.

Tires are new, fluid level ok, road conditions dry, conservative driving. My wife normally drives the Q and said this has happened several times over the past week. I see the several replys about fuses. If this was a blown fuse problem it would be constant.

I have looked at the FSM first then decided to come here and search.

Thanks

[CGB]

Hi aaronl,

I had the same problem with my 92 Q45 a few years ago. It turned out to be a relay located by the battery tray. I found the problem by pulling the codes from a box, which is located in the trunk, under the parcel shelf, near the driver's side rear speaker. I'm not quite sure what this box/cpu/ is called. I just followed the FSM.

Mind you that I don't know if this will apply to your model year.

I looked at the 95 FSM and in page 255, under EL, it shows the location of the TCS relay.

Sorry, it's late now, but I'll look at the 95 FSM tomorrow and see if I can provide you with more info.

Maybe other members with more experience might offer better troubleshooting tips.


Modified by CGB at 8:41 AM 11/2/2004

[CGB]

Hi aaronl,

I've been reading the FSM on the BR section, specially from page 68 on to page 78+. There's the TCS control unit in the trunk and the TCM (Traction Control Module) in the cabin.Both units have self-diagnosis test, but it appears that they don't share the same codes.

The TCM will retain the codes and Consult can pull these.The TCS control unit won't retain codes, but if you'll follow the procedure in the FSM, you should be able to read the codes. It's pretty easy.

I don't know how much of your time you want to spend on this, but if I were in your shoes, aside from checking connectors, I'll at least try to get the codes from the TCS control unit.

I think that will give you a good starting point and then you can decide if you want to check codes on the TCM or have it done by the Consult.

As I mentioned in my previous post, I wouldn't discount the relay, as it solved my problem.

I hope that this info will help you a little bit.

Maybe Q45 Tech might shine his wisdom light in this subjet.

Good luck!

[mattd1979]

I am having the same problem also. I get a code 18 off of the TCU. Usually after about 30 seconds from starting the car the lights will come on but today after driving about 10 minutes the lights turned off and it worked fine until I turned off the car. Once I started the car it was back to it's old routine again.When it was working and I turned the TCS off I did notice more power than when it was not functioning because when those lights are on it is in fail-safe mode and limits the power of the engine to a certain extent. According to what I have read in the shop manual. The car is a 1991 with 192,000 miles.Any Ideas?
Modified by mattd1979 at 9:46 PM 11/2/2004

[Q45Viper]

Final answer...The two TCS relays are going bad. ....Remove battery and battery tray, there are two relays for TCS underneath, replace both. Very common problem. They are not even very expensive. Call Joe at Scottsdale. He will know exactly what you are talking about. Eventually they will just light up permanently and the system will be disabled all the time. You do not have Traction control enabled if these lights are lit.