I have a ‘99 Corvette that I recently installed a cam on. I did the whole project in my garage and kept the engine in the car. My issue is since I put it all back together, my traction control doesn’t work at all. When I first turn the car on and drive maybe a mile, it says active handling warming up. 10 minutes or so later it will say service active handling and service vehicle soon.
The codes read :
28-TCS C1234 H
28-TCS C1243 H
28-TCS C1278 H
28-TCS C1283 H

I wrote those down and tried to look them up. Couldn’t find much of anything useful. I’ve taken the connectors off of the EBTCM cleaned, and reconnected. I’ve also cleaned and reconnected all 4 wheel speed sensors. Nothing seemed to be out of place or broken. Anyone have a clue as to what it could be or how to diagnose my issue? Thanks in advance!

 

I would need to type a BOOK to answer all the things that you need to do. If you want you can call me. We will discuss all of the issues. PM SENT...

Bill

 

Here is some info on these DTC´s .
Have you checked the 40A MaxiFuse and the ground G101 and G108 (below battery)?
These images shows the location of these Ground points .

 

If you have speed sensor DTCs, you MOST LIKELY have shitty connections at each FEMALE PIN. The Delphi female connectors SUCK and are easily damaged. There is a small tang in each female connector pin. That tang makes positive connection with the MALE PIN. When the female pin spreads apart, that tang makes a poor connection with the male pin. Thus the DTC.

The only way to accurately check the fit is to do a PIN PUSH PULL TEST. Insert a spare male pin into the female pin. There should be a POSITIVE GRIP on insertion and extraction. (sounds sexual doesn't it??) If there isn't a good positive grip, there is a BAD connection in that female pin. TWO WAYS TO FIX:
1. Replace the bad female pin
2. Use a small PICK and bend the female pin tang to make proper contact

In each FRONT WHEEL Well there is a WSS JUMPER HARNESS. It connects to the HUB Pigtail and plugs into the chassis wiring harness connector on top of the frame rail. Ther are female pins in that jumper harness and in the connector on the frame. CHECK THEM!

If you get a Multimeter, set it on the AC VOLTS Scale 0-20 VAC and measure the output of the hub speed sensor, here is what you should get 0 - 8 VAC (depending on how hast you can rotate the wheel! LOL! Yes ,, it puts out a AC voltage well sort of. The meter sees AC signal better. It has a toothed reluctor and puts out a weird pulsed DC signal..

Look for damaged female pins on all the WSS connectors that are erroring out.

I cam e-mail you pictures of a new connector and a BAD one. Pictures are worth a thousand words.

Bill

See the book is already starting

 

IF, you didn't keep the steering wheel and the steering shaft in the exact same position as it was before you disconnected it, you caused a misalignment between the Steering Wheel Position Sensor and the actual car steering gear being straight.

That causes the Active handling warming up. It really means that the EBTCM can NOT complete all of its start up test that it needs when you turn the car on. Part of that test is it checking the wheel straight ahead vs cars actual direction. Another way to look at it is; When its misaligned, there is steering wheel input to the LEFT or RIGHT and the EBTCM Accelerometers are sensing that the car is going straight ahead. It doesn't compute so the EBTCM errors out and disables Active Handling and other steering safety aids.

Did you make sure that there was no steering wheel movement while the shaft was disconnected from the rack? OR you had the wheels tured LEFT or RIGHT during the project and someone moved them to a different position before the shafts were reconnected.

BC

 

I think that might be the issue. Only problem is I had a bunch of family helping out. Anyone of them could have turned the wheel and none of them will remember. Is there a way to reset it without guess and check? Or a process to realign it?

ill go for a test drive and see which code has an H and a C at the end to see which one is the main issue.

 

I just got back from my test drive. The only code with a C at the end was 28-TCS C1283 H C

 

I have checked all of the fuses in the car, and I have just recently cleaned all of the grounds I could find right before this winter. I had electrical issues that I couldn’t figure out so I cleaned like 12 different ground wires. Both of those I believe were among the ones I cleaned and inspected.

 

The GM Tech2 can show you the value of that sensors PHASE A and PHASE B VARABLE RESISTORS. Each one should read a specific voltage at zero steering wheel angle. You would have to set the front wheels to Straight ahead, disconnect the steering shaft from the steering box. Once the steering wheel is able to spin freely, you would turn it in the direction that will get the phase a and phase b values to null value.

You could back pin the SWPS connector and read each phase with a meter and see where you are at.

If I remember correctly the null voltage is like 2.~ something volts on each side.

NOTE!!!! If someone rotated the steering wheel TOO far in one direction while it was disconnected, it will break the clock spring inside the column.

Bill

 

I found a thread saying to check the voltage of the blue wire on the SWPS with the key turned on. Said when the wheel is straight it should read 2.5 volts. I tried that, and it read between 10-11.5 volts. I would barely touch the wheel and it would jump all over the place between .04V and back up to almost 12v. I tried turning the wheel 360° in each direction and all it did was jump all over the place.
Note : the forum didn’t specify which year C5, and I thought they updated the SWPS in 01. I don’t know if it’s supposed to have different voltages between the years.

 

Here is the signals shown in Tech2win shown for my 00 car .
The analog volt is 2.73 volt when my frontwheels was fairly straight lined up is my screendump shows.
The Phase A and B signals is not possible to measure ( As far as I know ) .
When I look through my screendumps from Datalist 1 and 2 on Chassis(EBCTM) , I can not find any values for the Phase A and B as Bill Curlee mention, only the analog voltage.
Hopefully your clock spring is not broken and you can does as Bill Curley says , disconnect the steering shaft and following his instructions

 

Problem solved. It was definitely the SWPS. The steering wheel was 360° counterclockwise. When I used the volt meter the first time it was on the wrong wire. I have driven the car 3 times with no lights coming on. Thank you to everyone who helped me to figure all of this out!