Hi all,

I have searched and had trouble finding relevant information.

My car is a 2003 Z06. It is modified for the track (road course) but no electronic modifications.

This almost never happens on public roads, but after about 2 laps on the track, I will always get the "Service Traction Control", "Service Active Handling" and "Service ABS" warnings, and all electronics are disabled, including, frustratingly, the electronic brake bias, which makes my braking really dicey.

When I turn the car off and then back on, everything resets (until another 2 laps on track). I get the C1234 code as a history code in the DIC when it wasn't there before.

I changed the rear left hub and the problem still happens so it's somewhere else. Connection to the sensor looks good, no damage apparent.

Where else should I/can I look? Any other connection on that circuit that is prone to failure due to heat or lateral loading/vibrations? What are the troubleshooting steps? I have read that in the front, there are jumper harnesses that you can reverse to isolate the problem to them, but not on the rear.

Thanks in advance for your help.

 

Here is a link that may help. If not let us know.

http://www.digitalcorvettes.com/foru...d.php?t=159379

 

Thanks, I had seen this link already and a few more posts by Junkman. Contrary to the situation in that post, my code is isolated to the LR. I have already checked the connection at that corner and changed the hub assembly without success.

Problem must be farther up but where? Not easy following the wires, the ones coming from the LR seem to be going to a big bunch of wires close to the transaxle in the rear before heading to the front. There isn't an additional connection that I can see but I am no expert.

 

Will look at the FSM wiring and get you some more info.

 

Thanks, appreciate it.

 

There appears to be one connector before the EBCM connector. This C148 connector apparently brings all four wheel sensor wires thru it. Not sure where it is at but will try and find out. If it were me I would measure the resistance in the 2 LR wheel sensor wires from the LR sensor to the EBCM connector. You would just need to use some wire to extend the ohmmeter probes. I can get you the EBCM connector pinouts (22 and 8) drawing for you if you want to try.

Have you seen what the FSM says about diagnosing C1234? If it was not in the link I sent I can include that also if you want it.

 

dadaroo, both would be great. One of my friends has the Service Manual but I haven't been able to get a hold of him. And the wiring diagram would probably help a lot too.

Thanks for all your help.

 

Here you go. The FSM says that connector C148 is a 10 cavity connector so apparently something else besides the 8 wheel sensor wires go through it. It also says it is on the RH side of the engine and under the battery. Have not found a picture/drawing of the location yet. Maybe you have had some battery leakage onto the connector? Let me know if you need any more help and let us know how you do on this.

 

OK, I found one more wire that goes thru C148. It connects the ESC module and the EBCM and share the Steering Position Sensor Signal This is a Light Blue wire. Now you just have to look for a connector with all the Wheel Sensor wire colors plus a Light Blue wire. I don't know if the 10th pin is used or not but you should be able to ID the connector by the wire colors

 

Now THAT is interesting since I seem to very occasionally get the C1283 "Excessive Time to Centre Steering" error code as well. There must be some kind of a problem with this connector. Do we have any idea where on the car that connector is?

Thanks again for your help!

 

Read my post#8 again. It is under the battery. If you can't find it I will put my car in the air and help locate it. Not at home now but will look at code C1283 later. Sounds like the connector may be an issue. We will solve your problem(s). A bad connection is a cheap fix, hope that is it.

 

Sorry about that, read too fast to get to your other post... Will look and let you know. Let's not add an "s" to my problem!

 

Forgot you have a ZO6 so you should not have an ESC module so forget about looking for that wire in the connector(it may or may not be there). The ESC is only for the F45 suspension.

Here is some info on the C1283 code. If you need a connector pinout of C102 let me know. It is a 16 pin connector. At this point, the only thing common to both codes is the EBCM.


DTC C1283 Excessive Time to Center Steering




Circuit Description
Steer angle centering is the process by which the EBCM calibrates the steering sensor output so that it reads zero when the steering wheel is centered. The initial steering wheel center position is calculated after driving 10 km/h (6 mph) for more than 10 seconds in a straight line on a fairly level surface. The EBCM uses the Yaw Rate Sensor, Lateral Accelerometer and Wheel Speed Sensors to tell if the vehicle is moving in a straight line. This centering routine is necessary to compensate for wear in the steering and suspension. Wear in the steering and suspension can result in a change in the relationship between the steering wheel and the front wheels. By running the centering routine the EBCM can compensate for these changes by changing the digital and analog center position.

Conditions for Setting the DTC
The initial steering wheel center position will be determined quickly unless there is a large offset in the yaw sensor or lateral accelerometer output. When this happens the system will believe the steering is far off center even though the vehicle is being driven in a straight line. Under this condition and with a continuous vehicle speed of 40 km/h (25 mph) or greater for longer than 10 minutes, DTC C1283 will be set.

Action Taken When the DTC Sets
ABS and TCS remain enabled, Active Handling is disabled.

Indicators that turn on: Car Icon (TCS indicator)
Messages displayed on the DIC: Service Active HNDLG Service Vehicle Soon
Conditions for Clearing the DTC
Condition for DTC is no longer present and scan tool clear DTC function is used.
Fifty ignition cycles have passed with no DTCs detected.
Diagnostic Aids
It is very important to check the vehicle for proper alignment. The car should not pull in either direction while driving straight on a flat surface.
It is very important to find out from the driver when the code was set (when the SERVICE ACTIVE HNDLG message was activated). This information may help to duplicate the failure.
It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction. Check connector C102 RH side rear of engine compartment for water intrusion or missing plugs, and that the connector is oriented horizontal to prevent water intrusion.
An intermittent malfunction is most likely caused by a poor connection, rubbed through wire insulation, or a wire that is broken inside the insulation. Refer to Testing for Electrical Intermittents in Wiring Systems.
The Snapshot function on the scan tool may help in finding an intermittent DTC C1283.
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.

This step checks for the proper Lateral Accelerometer input.

This step checks for the proper Yaw Rate Sensor input.

DTC C1283 Excessive Time to Center Steering Step
Action
Value(s)
Yes
No

1
Was the Diagnostic System Check performed?
--
Go to Step 2
Go to Diagnostic System Check - ABS

2
Turn the ignition switch to the ON position, engine OFF.
Using a scan tool read ABS/TCS/Active Handling DTC(s).
Are any of the following DTC(s) present, C1221-C1235, C1282, C1284, or C1285?
--
Go to the Applicable DTC. Go to Diagnostic Trouble Code (DTC) List/Type
Go to Step 3

3
Turn the ignition switch to the OFF position.
Disconnect the EBCM connector.
Install J 39700 Universal Pinout Box using the J 39700-25 cable adapter to the EBCM and the EBCM harness connector.
Turn the ignition switch to the ON position, engine OFF.
Using J 39200 DMM, measure the voltage between terminals 22 and B of J 39700 .
Is the voltage within the range specified in the value(s) column?
2.3-2.7 V
Go to Step 5
Go to Step 4

4
Replace the Lateral Accelerometer. Refer to Lateral Accelerometer Replacement .

Is the replacement complete?
--
Go to Diagnostic System Check - ABS
--

5
Using J 39200 DMM, measure the voltage between terminals 21 and B of J 39700 .

Is the voltage within the range specified in the value(s) column?
2.3-2.7 V
Go to Step 7
Go to Step 6

6
Replace the Yaw Rate Sensor. Refer to Yaw Rate Sensor Replacement .

Is the replacement complete?
--
Go to Diagnostic System Check - ABS
--

7
Read the diagnostic aids and conditions for setting the DTC.
Cycle the ignition switch from the OFF to ON position.
Carefully drive the vehicle above 40 km/h (25 mph) for 10 minutes, while monitoring a scan tool for ABS/TCS/Active Handling DTC(s).
Did DTC C1283 set as a current DTC?
--
Go to Step 8
Go to Diagnostic System Check - ABS

8
Replace the EBCM. Refer to Electronic Brake Control Module (EBCM) Replacement .

Is the replacement complete?
--
Go to Diagnostic System Check - ABS
--

 

Thanks. It might also be a fluke as I had the car aligned a few times recently; perhaps that code was a result of not centering the wheel perfectly? Anyway it's not coming back at the same time as C1234 so I'll concentrate on that.

We'll follow the wiring diagram you gave me and see what we can find.

 

10-4, that is what I would do. Keep me in the loop.

 

Here's a tip if it happens on track again: You can turn the key to the "start" position while the car is running and it will reset the dash/electronics. It won't engage the starter. Sometimes this will clear the error for you. It's not a fix, but at least it won't ruin your session.