01Blk*SS*

iTrader: (4)

Hello,
I recently swapped out my 10bolt rear end for a MWC Fab 9. I had the rear end narrowed 3" per side, so I had to bend the **** out of my brake lines for them to fit for now. I know thats a halfass way, but will be installing shortened lines soon. So my question is, what would cause my low trac light to come on going 60-65mph on the highway? The gears were only increased from 3.42's to 3.50's. Also, I have 3" wheel adapters on right now since my 3pc wheels are not finished being built.
Any help would be great!
thanks!

MidwestChassis

iTrader: (5)

The fix for this problem should be recalibrating the computer for the gear change.

01Blk*SS*

iTrader: (4)

Hopefully that works, I was just curious as I know a few people who didnt have this problem.

00ssmg

iTrader: (4)

it depends. are you running the factory wheels and tire size? if so i would look into the airgap on the wheel speed sensors and reluctor rings if its a 4chn rear. eric at mwc is a good guy he will help you out if you cant figure it out.

01Blk*SS*

iTrader: (4)

Is the airgap adjustable?

00ssmg

iTrader: (4)

if it is a four chn car then no. at least not in my book. you have to grind out the new housing ends or the backing plates. neither are the right way. use a feeler gauge and let us know what the air gap is between the sensors and the reluctor rings. if i remeber correctly i think it is going to be between 40-50 thousands.

MidwestChassis

iTrader: (5)

I'm sorry I wish I would of seen this before I left the shop. I would of got you all the proper measurements you needed. I might be swinging in their tomorrow because we have a ton of stuff going on I will look it up and get back to you, other wise i will call Eric and have him get the measurements you need.

MidwestChassis

iTrader: (5)

Distance from the back of the wheel studs to the ring is around 60-80 thousands and the sensor to the ring is 45 thousands.

Something that popped into my head that can be causing an issue is this right here as well.
I would get your new wheels on with out the spacers and see if that changes anything.

89 formula350

iTrader: (8)

I thought if you swapped the sensors from left to right the cut part is facing out and causes this too... just a thought

01Blk*SS*

iTrader: (4)

It is a 4 channel car, ASR and ABS. I hope with all the suggestions I can get this problem fixed.

Thanks for the specs! I will check the tolerances after Christmas when I get back home. I will be performing the three suggestions; check reluctor ring/sensor air gap, drive the car without the adapters, and recalibrating the speedo. Also how would you recommend the calibration of the speedo, hptuners?
thanks!

So are you saying, if I re-assembled them on the incorrect side, the sensors are not interchangeable due to the geometry of the sensor tip?
I will check this also, but pretty sure they are on the correct side of the car as I labeled them.

01Blk*SS*

iTrader: (4)

Okay so I finally got my new wheels on with the correct backspacing. After driving the car with no wheel adapters, I am still getting the low trac light. Another light has been coming on since I have started to drive the car again. So the low trac light comes on and off but only at highway speeds, once I am driving for around 10 minutes on the highway the ABS inop light comes on..... I am getting hptuners by the end of the month and will calibrate the gears, and Im checking the air gaps tomorrow. If these two things dont work, what would be the solution Midwest?

Scoobysnacks

iTrader: (1)

I had sort of the same problem when I did my s60 swap with 4:10s. My traction control would come on when I stepped on the brake pedal. The sensors for the traction control are magnets and a bunch of crud stuck to them during the swap. Cleaned them off and everything was fine. Its worth the check..

MidwestChassis

iTrader: (5)

Check the air gap, recalibrate for the tire height and gear change, check to make sure a sensor didn't go bad, make sure the sensors are plugged in all the way, and making sure they are clean is also another good option.

The backing plates, reluctor rings, and sensors are all units that came off your vehicle. The housing itself doesn't dictate anything to do with TCS, how ever gear ration can as well as tire size.

01Blk*SS*

iTrader: (4)

So I just checked the gaps for the reluctor rings, cleaned the sensors and made sure they were in all the way. I checked for any codes on my buddys hptuner scanner and no bad sensors. I will be buying hptuners soon so I can recalibrate tire height and gear change. Trying to eliminate all your suggestions, thanks!

This is what they measure:
-Distance from back of the wheel stud to the ring is:
driver side: 0.035"
passenger side: 0.040"

-Distance from the sensor to the ring is:
driver side: 0.080"
passenger side: 0.065"

Looks like the gaps are way out of spec unless your got your measurements backwards?

here are pics of what I was measuring, these pics are of the driver side.

MidwestChassis

iTrader: (5)

From the out side of the flange (wheel side) to the back side of the ring(center section side) should be 1.33.

01Blk*SS*

iTrader: (4)

okay, but how is that relevant for the traction control system to work correctly when the important gap is the distance from the reluctor ring to to sensor?

MidwestChassis

iTrader: (5)

Because you need to make sure the ring isn't spinning out of round. A ring a little off will indeed change the gap to the sensor.

01Blk*SS*

iTrader: (4)

that makes sense, Ill recheck it this weekend. I also ordered hptuners today so I can calibrate the speedo, tire height.
thanks again!

01Blk*SS*

iTrader: (4)

So I just re-calibrated the tire size and gear ratio and still getting the low trac light at highway speeds. Here are the codes that came up:
[Brake] C0046 - Brake Pressure Sensor A/B (History)
[Brake] U1000 - Class 2 Communication Malfunction (History)
[Brake] C0245 - Wheel Speed Sensor Frequency Error (History)
[Restraints] U1000 - Class 2 Communication Malfunction (History) (Immature)
[Restraints] U1016 - Loss of Class 2 Communication with VCM (History) (Immature)
[HUD] U1000 - Class 2 Communication Malfunction (History) (Immature)

Any idea? Ill check the flange to ring gap this week and get back...

MidwestChassis

iTrader: (5)

It doesn't look like it is communication with the sensor, bad sensor, frayed wire, sensor not bolted in square with the backing plate, grease or debris on the ring or sensor itself, voltage and reference test at each sensor find the abnormal reading and make sure your rotor isn't bent or the pads grabbing.