Today I got off work and started driving my Z to get a previous problem fixed, but the ABS, Brake, TCS, and SLIP light turned on. The previous problem I mentioned I was going to get fixed at the moment was a stud got cross-threaded when NTB was installing my tires. I was driving with 1 missing lug nut for about 25 miles, 15 of which the 4 lights where on. I was skeptical that the missing lug was the reason that these lights were on but after NTB installed the stud and lug it didn't go away.

I then read on this site for about 2 hours looking for similar problems and found a few threads which had a few solutions, and I checked if these could be mine.
What I found:

Common Problem #1 - Low Brake Fluid
I got home and checked my brake fluid and it was almost exactly on the max level, so this wouldn't be the problem.

Common Problem #2 - Wheel Size Difference EDITED: I tested a set of 215/45/R18 in the front and it still flipped the lights on.
My wheels are slightly off, I have 205/40/18 on stock wheels in the front, and 245/45/18 in the rear. The reason why I don't think this is the culprit is because I drove for about 1000 miles with almost this exact set up. The only difference from the setup I had before and now is that the rear tires are full tread, 10/32nds instead of 1/32nd-2/32nd.

Common Problem #3 - Aftermarket Suspension
Im currently lowered on coil-overs about a 3.5-4 inch drop, I have been this low for about 8000 miles so i'm nearly certain this is not the problem.

I can turn the car off and if i'm not driving anywhere then these codes will not show up, as soon as I drive about 2 wheel rotations these lights turn on. I was playing around with the system seeing if I could get any more information for diagnostics and I found out that if I am rolling and I turn the car off (I drive a 6spd) and turn the car back on the lights wouldn't turn back on. Once I had these lights off I toyed around a little bit more and downshifted to 5th, and then to 4th and nothing happened. I then down shifted to 3rd and got a little bit of wheel spin and the light turns back on.

Some of the things I have tried as a solution is checking for a code (with a pocket code scanner) while the lights where still on and no codes where shown. I also disconnected the battery for about 25 minutes and the light still came back on. I also checked a few of the fuses and those are also intact.

After I try a few other things I will be out of ideas, I really need someones help with this. Thank you for reading this whole post and responding.

 

pretty sure it has to do with the difference in tire sizes, its throwing your car off.
I have seen a few other posts like this and every time they are running different tire sizes, not usually a big deal, but if you are running staggered set up and its too far from OE size it messes with the car. See if you can find someone with OE wheels and Im willing to bet it fixes your problem

 

I was about to test that, I have a friend with a lancer, it has the same bolt pattern and the size of the tires are 215/45/R18 so they are nearly the same tire. If I understand right the computer reads the aspect ratio and rim size (total combined height) rather then the width so those tires/rims would work for a test right?

 

NTB damage the wheel speed sensor. Computer is getting no signal from one wheel while getting good signals from the others so it freaks out and throws all the lights on cause it doesn't know what to make of it.

Wrong tire sizes will throw TCS/VDC/Slip lights but all you have to do is press the TCS/VDC Off button and you can drive normally.

 

Yeh, I tested the wheels, and the entire system did the same thing. So that one can be marked out, and im starting to think that it is more possible that could be true. They did an alignment before that and I asked them for tire prices and they gave me a good deal cause I purchased the alignment. Where is the wheel speed sensor located on the Z's? do you think either jacking a car up or doing an alignment could end up damaging the wheel sensor? (is it in the proximity)

Edit: I also tryed hitting the TCS button when the lights came on also. I have an ASE in electricals and went to school to learn this **** so I have a good base knowledge on it all. Maybe I can locate the wheel sensor and see if it looks damaged.

Also it came on after 50 miles if it was damaged at NTB wouldn't it come on immedatly? I don't want to accuse NTB without being certain that it was them.

 

i'm guessing it was a front wheel stud - right? the speed sensors ae mounted on the back side of the wheel hub. follow the wire down the front shock to the sensor.

 

The wheel stud that got damaged was on the left rear. Im going to look at the wheel sensor for damage in just a minute. Ive only got 85700 miles on my Z, so nothing should be going bad yet, im kinda pissed cause this is happening right now.

Edit: Both front sensors appear un-damaged and untouched, Im not sure if the rear has them cause I couldn't find anything obvious.

 

Rears are mounted inboard on the differential cover.

My bets are on tire size or there alignment threw off you steering angle sensor somehow.

 

Since I tested the wheels with another set of wheels that are nearly the same size as mine, just a different offset and a little smaller width I don't think that is the problem. I also have driven with nearly the same setup for about 1000 miles, it would have tripped the code closer to when I put the different tires on.

The steering angle sensor could be it since I did get an alignment, im going to bring it to the dealership today and get the code ran and possibly get this problem fixed if it isn't too much money.

 

If you start the car and turn off VDC or TCS before driving/moving, do the lights still come on?

 

I just tried that and the lights still came on as if I never turned the TCS off, I own an enthusiast model so I've got TCS.

 

^To me, that further rules out incorrect tire size/stagger as a culprit. Maybe focus on the speed sensor advice the others are giving you.

 

Brought it to the dealership and they ran a code on it and said the ABS module was bad. It is going to get replaced in about a week costing me 1600 dollars... hopefully they are right and this doesn't screw me.

 

Can you get that module on ebay?

 

I would look up the seller turbotoys on ebay, he has sold me alot of oem parts that i needed for cheap. Buy this and replace it yourself.

 

pretty sure it has to do with the difference in tire sizes

 

Any luck on this having very similar problems and its driving me insane

 

Did they happen to give you a print out of the code/data. It would help a lot.

 

Please disregard.

 

Had my car aligned the other day,when they pulled it off the rack the tcs,abs,brake, and slip light came on cant find the problem, any help. I also got it home and put it on the lift, started the car put it in neutral rolled the front wheels by hand and it made lights come on again. Turned it off started it again rolled the back wheels they didn't come on
2004 350z