Variation on the ABS/TCS/AH theme..
Thread Starter
Drifting
Joined: Feb 2005
Posts: 1,770
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From: in ur mirror, 'bout to pass.. CA
Variation on the ABS/TCS/AH theme..
I've searched and read about the problems that plague our 'vettes regarding the "three of safety", yet I needed to vent and see if anyone else has dealt with my particular woe. So, here it is:
Last week I changed out my worn brake pads. Nothing tuff there, straightforward, done it dozens of times. Went to an uncompleted portion of my subdivision to bed in the brakes. After several stop and go's at the recommended speeds, I tried an ABS stoppie, to remind myself what ABS felt like when it activates (I don't have occasion to use it, but like knowing it works when needed). A quick first-gear run up, and I stand on the stop pedal. All works as intended. I cruise home, park the girl and call it a night. The next day, preparing to go to work, I fire her up, and instantly get all the wrong warnings: Service ABS/TCS/AH. Ah well, must be another dirty ground. I drive to work thinking a cycle or two will clear her up. No big thing, right? No joy. She's been through three drive cycles now, all at varying highway and in-town speeds, and still hasn't cleared the warnings. I'm not afraid of driving without the safety nets, but it is annoying. This is my first foray into the wizard world of electronics in our cars. Anyone else experience something similar?
Last week I changed out my worn brake pads. Nothing tuff there, straightforward, done it dozens of times. Went to an uncompleted portion of my subdivision to bed in the brakes. After several stop and go's at the recommended speeds, I tried an ABS stoppie, to remind myself what ABS felt like when it activates (I don't have occasion to use it, but like knowing it works when needed). A quick first-gear run up, and I stand on the stop pedal. All works as intended. I cruise home, park the girl and call it a night. The next day, preparing to go to work, I fire her up, and instantly get all the wrong warnings: Service ABS/TCS/AH. Ah well, must be another dirty ground. I drive to work thinking a cycle or two will clear her up. No big thing, right? No joy. She's been through three drive cycles now, all at varying highway and in-town speeds, and still hasn't cleared the warnings. I'm not afraid of driving without the safety nets, but it is annoying. This is my first foray into the wizard world of electronics in our cars. Anyone else experience something similar?
Safety Car
Joined: Aug 2000
Posts: 4,933
Likes: 30
From: San Rafael CA
Welcome to the world of electronics ..... the system is saying it has a problem .... you can "force" it to give you a pretty clear idea of what the problem is ... go here for instructions ....
https://www.corvetteforum.com/techti...D=26&TopicID=1
Post the codes and someone will help you out.
https://www.corvetteforum.com/techti...D=26&TopicID=1
Post the codes and someone will help you out.
Thread Starter
Drifting
Joined: Feb 2005
Posts: 1,770
Likes: 0
From: in ur mirror, 'bout to pass.. CA
The results are in..
Here's what I pulled after clearing the codes this afternoon for the drive home from work:
PCM-P1416 C: AIR system malfunction bank 2 (pass.)
TCS-C1214 H Solenoid valve relay contact or coil circuit open
RFA-C2100 H C Left front TPM sensor malfunction
From reading, I've learned that the C1214 is the proverbial "kiss of death" for the ABS module; looks like a rebuild is in my future for that module. However, I'll not be undaunted; I'll try cleaning the grounds first before I rip the heart out of the ABS module!
The other two I can live with; easy fixes. I'll keep you posted.
PCM-P1416 C: AIR system malfunction bank 2 (pass.)
TCS-C1214 H Solenoid valve relay contact or coil circuit open
RFA-C2100 H C Left front TPM sensor malfunction
From reading, I've learned that the C1214 is the proverbial "kiss of death" for the ABS module; looks like a rebuild is in my future for that module. However, I'll not be undaunted; I'll try cleaning the grounds first before I rip the heart out of the ABS module!
The other two I can live with; easy fixes. I'll keep you posted.
Last edited by Armycop; Jun 7, 2008 at 03:49 PM.
Pro
Joined: Dec 2006
Posts: 646
Likes: 22
From: Wilmington NC
join the club brother..after two years of problem free driving my Z caught the TCS STD...lol Ive cleaned all my grounds and attempted to clear the codes but no luck as of yet loosing the lights....c1214 C H on mine as well...if i find a fix Ill let you know asap!
Thread Starter
Drifting
Joined: Feb 2005
Posts: 1,770
Likes: 0
From: in ur mirror, 'bout to pass.. CA
What I don't get is why right after ABS was enabled? It was the very next day after my pad change and impromptu "stoppies" that the warnings lit up. Maybe I should go out and stomp on the brakes some more..might reverse the condition..
Safety Car
Joined: Aug 2000
Posts: 4,933
Likes: 30
From: San Rafael CA
The C1214 indicates this system relay has failed.
It would appear that the relay is unable to stand up to many years of use ..... somebody in GM either went to cheap on the part ... or underestimated the load/lifetime for the part.
Now sometimes a bad ground can cause the computer in the EBCM to think the relay has failed. That's why you want to be sure the EBCM ground points are clean. Replacing the EBCM will not fix the problem if it is a bad chassis ground.
Once you're sure that it is not an electrical supply issue, ship the EBCM to this guy and he replaces the relay ... apparently with a better one than GM used.
http://www.absfixer.com
Team Owner
Joined: May 2001
Posts: 36,836
Likes: 244
From: Dear Karma, I have a list of people you missed.
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16
Internal to the EBCM is the "system relay". This relay provides the power for the pump in the BPMV that generates brake fluid pressure. It also provides the power for the solenoids that the EBCM uses to open and close valves inside the BPMV. Basically the system relay provides the power for the electrical components of the EBCM and BPMV other than the EBCM computer.
The C1214 indicates this system relay has failed.
It would appear that the relay is unable to stand up to many years of use ..... somebody in GM either went to cheap on the part ... or underestimated the load/lifetime for the part.
Now sometimes a bad ground can cause the computer in the EBCM to think the relay has failed. That's why you want to be sure the EBCM ground points are clean. Replacing the EBCM will not fix the problem if it is a bad chassis ground.
Once you're sure that it is not an electrical supply issue, ship the EBCM to this guy and he replaces the relay ... apparently with a better one than GM used.
http://www.absfixer.com
The C1214 indicates this system relay has failed.
It would appear that the relay is unable to stand up to many years of use ..... somebody in GM either went to cheap on the part ... or underestimated the load/lifetime for the part.
Now sometimes a bad ground can cause the computer in the EBCM to think the relay has failed. That's why you want to be sure the EBCM ground points are clean. Replacing the EBCM will not fix the problem if it is a bad chassis ground.
Once you're sure that it is not an electrical supply issue, ship the EBCM to this guy and he replaces the relay ... apparently with a better one than GM used.
http://www.absfixer.com
And the nice part is, you'll still be able to drive your car in the meantime if you want to.
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Thread Starter
Drifting
Joined: Feb 2005
Posts: 1,770
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From: in ur mirror, 'bout to pass.. CA
Well, ****!
Today I tried the DIY method to fix my code throwing woes.
Pulled my battery, cleaned the grounds under the tray on the frame rail, cleaned the ground plug on the front of the LF and RF frame rails, buttoned her up, and prayed.
Still got 'em, only one now. "p01214 H C", you are the death of me.
went for a short jaunt to feel the power, and tried some stoppies again. Fronts didn't lock up at all, but the backs did quick. Soo, now I plan on removing the EBCM and sending it for repair.
Pulled my battery, cleaned the grounds under the tray on the frame rail, cleaned the ground plug on the front of the LF and RF frame rails, buttoned her up, and prayed.
Still got 'em, only one now. "p01214 H C", you are the death of me.
went for a short jaunt to feel the power, and tried some stoppies again. Fronts didn't lock up at all, but the backs did quick. Soo, now I plan on removing the EBCM and sending it for repair.
Thread Starter
Drifting
Joined: Feb 2005
Posts: 1,770
Likes: 0
From: in ur mirror, 'bout to pass.. CA
Took pics as well
but I can't host them here. anyone willing to host the pictures of the ground locations in the engine bay, plus the service manual schematics?
Mac
Mac
Tech Contributor
Joined: Oct 1999
Posts: 41,058
Likes: 9,820
From: Charlotte, NC (formerly Endicott, NY)
ABS Power and Ground Circuit Schematics
Ground Locations on Car
(1) G302
(2) G402
(3) G401
(4) G205 and G301
(5) G201
(6) Grounding Point for Engine Ground Strap
(7) G101
(8) G102
(9) G104 and G108
G108 provides the ground for the EBCM electronics while G103 (located near G101) provides the ground for the BPMV pump motor. The pump motor circuit goes through the relay in the EBCM. If the pump motor is turning slowly the current draw goes higher and may cause the relay contacts to burn. This would cause intermittent contact problems. High resistance in the power feed to the pump motor circuit could also result in 1214 being called out. If the power or ground to the EBCM electronics isn't connected through low resistance contacts the EBCM may not operate properly which could affect the relay closure.
Bill
Ground Locations on Car
(1) G302
(2) G402
(3) G401
(4) G205 and G301
(5) G201
(6) Grounding Point for Engine Ground Strap
(7) G101
(8) G102
(9) G104 and G108
G108 provides the ground for the EBCM electronics while G103 (located near G101) provides the ground for the BPMV pump motor. The pump motor circuit goes through the relay in the EBCM. If the pump motor is turning slowly the current draw goes higher and may cause the relay contacts to burn. This would cause intermittent contact problems. High resistance in the power feed to the pump motor circuit could also result in 1214 being called out. If the power or ground to the EBCM electronics isn't connected through low resistance contacts the EBCM may not operate properly which could affect the relay closure.
Bill
Last edited by Bill Dearborn; Jun 11, 2008 at 06:09 PM.
Thread Starter
Drifting
Joined: Feb 2005
Posts: 1,770
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From: in ur mirror, 'bout to pass.. CA
thanks, but what I meant was..
Thanks for that Bill, but what I meant was I took photos of the actual grounds from my car, and I wanted to post them here! 
Can I send them to you via e-mail, and you post them for me?
BTW, did those schematics come from an e-version of the service manual??
Can I send them to you via e-mail, and you post them for me?
BTW, did those schematics come from an e-version of the service manual??
Thread Starter
Drifting
Joined: Feb 2005
Posts: 1,770
Likes: 0
From: in ur mirror, 'bout to pass.. CA
it's off to absfixer for me
Pulled the EBCM this afternoon, boxed it up and shipped it off to absfixer. Hopefully this'll do the trick. I like having the safety net there for when I step over the cliff. I got wise after unscrewing three of the six torx bolts and removed the upper radiator hose. little leakage, but it sure made getting to the other three a breeze.
Drifting
Joined: Jun 2002
Posts: 1,945
Likes: 41
From: Corinth TX
Good luck with everything. I hope it all works out well for you. Its ashame that GM makes such a great car overall but yet it plagues so many of us with this problem. What I truly find amazing is that there has never been a recall for this particular item.
