Need help with ABS/TC codes
06-25-2016, 01:24 PM
#1
Instructor
Thread Starter
Need help with ABS/TC codes
Car is 08Z. I have a light that comes and goes. Sometimes doesn't show up at all and other times pops up right when the car is started. Went to have the current code read and basically all it said was that the EBCS is detecting an issue with another module, and didn't give out any specific information (C0561). Someone please help!
UPDATE: The ABS light and other "service X" messages are coming up more frequently now. While just putting around, I generally ALWAYS have C0561 code and the TC on. That's about my "normal." However, when driving aggressively (auto x), I'll get service ABS, service vehicle soon, shocks inoperative (??), service ride control, service traction control, service active handling...just about everything that can go off does. Then when I resume normal driving it pretty much goes back to just traction control light and C0561. When I had service ABS come up randomly one day I tried to read the code and it said no codes were current or in histories other than C0561, but the ABS light was illuminated and the emergency brake light was lit up. I also went over a bump today and had ABS pop up again, so I quickly plugged the scanner in and got C0281 as a history and C0550 as a history...but it was only a brief second that it popped up. I'm starting to think this problem is deeper than I originally thought and may turn out to be expensive. What the heck do I do now? It's a lot of "service X" going on and I don't want to continue to push the car with these gremlins not figured out.
UPDATE: The ABS light and other "service X" messages are coming up more frequently now. While just putting around, I generally ALWAYS have C0561 code and the TC on. That's about my "normal." However, when driving aggressively (auto x), I'll get service ABS, service vehicle soon, shocks inoperative (??), service ride control, service traction control, service active handling...just about everything that can go off does. Then when I resume normal driving it pretty much goes back to just traction control light and C0561. When I had service ABS come up randomly one day I tried to read the code and it said no codes were current or in histories other than C0561, but the ABS light was illuminated and the emergency brake light was lit up. I also went over a bump today and had ABS pop up again, so I quickly plugged the scanner in and got C0281 as a history and C0550 as a history...but it was only a brief second that it popped up. I'm starting to think this problem is deeper than I originally thought and may turn out to be expensive. What the heck do I do now? It's a lot of "service X" going on and I don't want to continue to push the car with these gremlins not figured out.
Last edited by Eyedeas; 07-02-2016 at 04:22 PM.
06-25-2016, 06:23 PM
#2
Le Mans Master
You have 3 CAN failures, one with the ECM, one with the BCM and one with the EBCM. I am going out on a limb here and suggest you check the 13 ground points for solid grounds front of car to back.
If these codes were written in the order in which they were read, after each network "glitch, there was a series of Chassis, or body codes in groups. Probably logical as a loss in CAN basically causes all the interacting modules to lose data with each other. Glitch is a glitch as comm was reestablished otherwise you'd be on the side of the road.
Did they clear these code groups? Is the ECM running in closed loop now?
If these codes were written in the order in which they were read, after each network "glitch, there was a series of Chassis, or body codes in groups. Probably logical as a loss in CAN basically causes all the interacting modules to lose data with each other. Glitch is a glitch as comm was reestablished otherwise you'd be on the side of the road.
Did they clear these code groups? Is the ECM running in closed loop now?
06-25-2016, 06:45 PM
#3
Instructor
Thread Starter
You have 3 CAN failures, one with the ECM, one with the BCM and one with the EBCM. I am going out on a limb here and suggest you check the 13 ground points for solid grounds front of car to back.
If these codes were written in the order in which they were read, after each network "glitch, there was a series of Chassis, or body codes in groups. Probably logical as a loss in CAN basically causes all the interacting modules to lose data with each other. Glitch is a glitch as comm was reestablished otherwise you'd be on the side of the road.
Did they clear these code groups? Is the ECM running in closed loop now?
If these codes were written in the order in which they were read, after each network "glitch, there was a series of Chassis, or body codes in groups. Probably logical as a loss in CAN basically causes all the interacting modules to lose data with each other. Glitch is a glitch as comm was reestablished otherwise you'd be on the side of the road.
Did they clear these code groups? Is the ECM running in closed loop now?
Also, I have no idea where the 13 grounds are. Is there a link that can show me?
06-25-2016, 07:03 PM
#4
Le Mans Master
I am guessing (almost impossible to internet diagnose) you have an intermittent connection loss in the network. Grounds are a known problem and could cause these intermittent issues. The problem could be bigger such as a harness damage somewhere, but no way of telling you where to start.
Disconnecting the battery really does not reset/erase codes. Even if the engine light no longer is lit, does not mean the codes are gone as you've discovered by the long history list.
My advice to you is "think harness". Grounds are first, then start looking at connectors, wiring for obvious damage. The U codes are the primary failures, I believe.
If the car runs fine most of the time, then the ECM is cycling enough times to overcome the intermittent CAN glitches. BUT, these codes end up in history which the batt disconnect will not reset.
06-25-2016, 07:21 PM
#5
Le Mans Master
06-25-2016, 07:48 PM
#6
Instructor
Thread Starter
Thanks, I'll keep looking. I'm pretty much out of time before my track day, though. First HPDE is Thursday. It doesn't seems to affect anything though other than not being able to have traction control on, which is fine with me.
07-04-2016, 07:53 PM
#8
Im not a ton of help because im no expert but i might have an idea...
Ive just replaced steering angle sensors in both my 2011 GMC and 2013 Corvette GS because of the service TC/ABS lights and messages.
After i found out it was bad steering angle sensors i paid closer attention and realized the message/warnings dont come on right at start up, but rather as soon as i start moving the steering wheel. GL!
Ive just replaced steering angle sensors in both my 2011 GMC and 2013 Corvette GS because of the service TC/ABS lights and messages.
After i found out it was bad steering angle sensors i paid closer attention and realized the message/warnings dont come on right at start up, but rather as soon as i start moving the steering wheel. GL!