So I know there is tons of info on this on the forums but I seem to have a different problem than everyone else seems to have which prompted me to make the thread. First of all, it is intermittent and it seems to work after starting the car after driving for a while (around 20min) but if sits for longer than an hour even after driving around for the 20min then the lights on the dash come back on and ABS, TCS, and AH don't work.

Here is an example. I start up my car first time for the day, ABS and TCS lights are on so I take the 20min drive it takes to get to AutoZone so they can hopefully read the code to figure out what the problem is but then the light turns back off and everything works now when I start the car back up for them to read the code. Great...so I could never read the code to figure it out unless I were to leave the car there for way over an hour which isn't happening.

It is almost like there is a capacitor somewhere that takes a good 20min to charge for the system to work correctly but then looses all its charge after an hour. Could that be the ABS module? What else could it possibly be?

Any help is MUCH appreciated! Thanks!

 

You can read your own codes. No need to go to Auto Zone.
Access your codes and post them here along with the year, model of your car, and either auto or manual.
This is the FIRST thing you need to do and let us know what it is so we can diagnose what your problem is.


Without the codes it's hard to say but I'm leaning towards the EBCM as the culprit...

Another thing. How old is your battery. Low voltage batteries have been know to cause strange things in a C5.
Don't go by what your volt meter reads on the dash. That's showing charging volts.

 

Check your Ground points! do a search, there's tons of info on this little gremlin.

 

I had a similar issue that was moisture related, any time it was overcast or rained, or I washed it, it would do the same thing. I removed the main TCS module plug on the ABD module, snd the one in the fender, and the two front abs lines, cleaned them with contact cleaner and then put a **** ton of dielectric grease andeverything has been good since.

 

I agree. Pull them off and clean them. Not a big job, at all.

 

 

Thanks for all the recommendations guys! I have tried EVERYTHING y'all have mentioned. Checked the fuses, cleaned all the grounds in the engine bay (which were all filthy btw), replaced the battery, but unfortunately it's still intermittent as it has been.

So after I did everything that I just mentioned, I drove to class which the TCS and ABS lights were on, they were still on when I started heading back home but decided to get some sushi on the way. They finally went off on the way from the sushi bar back to home but today when I went to class it was the same ol' story that happened the same exact way. I even got the same sushi rolls to see if the lights would turn back off which they did but I'm sure they will turn back on when I drive to class tomorrow so here are the codes:

2003 Z06 6-spd:

28-TCS
C1242 H C
C1281 H
C1283 H
C1284 H

58-SDM
B0017 H C
B0026 H C
U1096 H

As I am typing this I just realized that I should have cleared the codes last night so I could see if the same codes came back up today but I just cleared them right now so I'll see what happens tomorrow.

Thanks again for ya'll's help! This has been the first car I have ever owned that I've never taken to the stealership because I always get such great guidance and motivation here. After taking care of the valve springs, tie-rod ends, sway bar end links, clutch, etc. I've probably saved about as much as I paid for the car over the 2 years that I've owned it by doing all the work myself! The Corvette brotherhood is real!

 

Your TCS codes sans the first are for the steering wheel position sensor. The steering mechanism in the C5 adjusts itself based on speed of the car so if a sensor is going out it can throw those codes. The first code, I believe, relates to brakes.

You're also throwing codes for power to the air bags. Is the air bag light on or have they been modified/removed?

 

I've had the same problem for a long time. If your dash lights up with codes and or gauges not responding, I suggest opening your drivers side door when safe to do so.

If the gauges work but you still have some messages left, then the culprit could and most likely be the wire harness that's located in the drivers side door.

I found my problem from the module below the speaker. Had signs of moisture on the RED COLOR terminals.

Here's my instagram video clip of what I was doing. "Small clip"

 

What about the ignition/switch. Mine throws random codes sometimes because of it (TCS, AH included). The way I understand it is if the computer don't see the proper voltage at start up then it throws the code. When I restart later there will be no code. Works fine even if/when it throws the code. Just a quirk I have learned to live with because I've been too slack to do something about the ignition/switch.

 

Here are the definitions for your codes

1. C1242 = ABS Outlet Valve Coil LR Circuit Failure : Chassis Control Module
2. C1281 = Lateral Accelerometer Circuit Failure : Chassis Control Module
3. C1283 = Switch Test Signal Failure : Chassis Control Module
4. U1096 = SCP (J1850) Invalid or Missing Data for Primary Id
5. B0017 = Air Bag - LF Frontal Loop Open
6. B0026 = AirBag -LF Frontal Loop Open

Ref: http://computer-logic.us/Obd2Lookup

U1096 may provide a key to the issue.. The ECU or Sensor that should be providing the primary ID for the system check was or is missing. If this code is missing, then the entire SCP system will not function properly.

HOW THIS WORKS (What do the code mean and indicate?)
Automotive CAN Buses are multi-drop and multi-master. What this means is that the bus has hundreds of commands being sent over the paired wiring harness. Each message has an ID in the data packets that identify the system and sensors, actuators, or ECUs doing and listening for the communications. Think of the ID as a NAME.

Simple Example:
Working System
Main Sensor Control Arrays: (Sends an instance message out to all of the teams across the car's corporation) Listen up team members. This is the manager of the SCP team. If you are on my team, here is a check list of tasks I want you perform. Report back as soon as you complete checking the items off the list.

Team Members: SCP? Yeah that's our team. Let's perform these tasks and report back to him that we have completed checking them off.

Not Working:
Main Sensor Array : Hey, my name is . I am sending you a list of the following tasks for you to perform. When you get the tasks done, please report back to me,

Team Members: ?? Who did he say he was? Does this even apply to us? Error in the communication, we do not know who was trying to communicate with.

The following scenario defines something like an open condition

Example:

Master ECU: Did you set the alarm before you left tonight?

Working Sensor: Yes, I did. It should be armed.

Master ECU: Well you left a door (aka circuit) open. So the alarm is not armed. It started going off soon after you set it. You need to close the door (circuit) so the alarm is set and working properly.

How to Fix or narrow down your particular issue.

It is possible that you CCM (Chassis Control Module is bad), and/or that your AirBag Sensor array or SDM ECU is bad as well. Possible, but with the other codes, you are throwing, doubtful.

It sounds like you have one of the following issues:
A. Low Voltage
B. Loose connection
C. Short
D. Grounding strap issue
E. Frayed Wires
F. Moisture has entered one or more ECUs or Control Modules.
G. A bad sensor or actuator which is not reporting required information or closing a circuit loop

Follow the posts pointing out the grounding straps and loose connection informational replies and go through a process of elimination.

Hope this helps and good luck!