ECM Issue
Thread Starter
Intermediate
Joined: Apr 2014
Posts: 31
Likes: 0
From: Beverly Hills Florida
ECM Issue
Hey All-
First, VERY new to corvette ownership. Still figuring things out and I don't have a super long history of wrenching on my own cars. That being said, had my 93 in for some service today and asked them to take a look at an issue for me. I was having issues with power surging through acceleration. Long story short, looks like a bad ECM. The shop said that it kicked off a Quad Driver Circuit Failed error. My guy said that I basically would need to replace the whole ECM. Said it was still drive-able, but if there is something wrong....it needs to be fixed...
So the big questions...
1. Where is the best place to pick up an ECM.
2. Should I attempt to install that bad boy myself or realize that I will probably be more detrimental to the vette than helpful...
Thanks for the feedback!
First, VERY new to corvette ownership. Still figuring things out and I don't have a super long history of wrenching on my own cars. That being said, had my 93 in for some service today and asked them to take a look at an issue for me. I was having issues with power surging through acceleration. Long story short, looks like a bad ECM. The shop said that it kicked off a Quad Driver Circuit Failed error. My guy said that I basically would need to replace the whole ECM. Said it was still drive-able, but if there is something wrong....it needs to be fixed...
So the big questions...
1. Where is the best place to pick up an ECM.
2. Should I attempt to install that bad boy myself or realize that I will probably be more detrimental to the vette than helpful...
Thanks for the feedback!
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
99.99% of the time a quad driver fault is caused by a short. Quad drivers turn on relays and solenoids. If there is a short and the circuit being driven draws too much current you will get a quad driver fault. It does NOT hurt the quad driver (or the ECM). The fault code will tell you which quad driver is complaining. See these links:
https://www.corvetteforum.com/forums...post1574918379
http://corvettephotographs.com/c4vettes/codes.htm
What they mean (note that the codes changed from year to year so make sure you're looking in the right section):
https://www.corvetteforum.com/forums...post1576116036
You need to determine which quad driver is causing the fault and then investigate the circuits associated with that quad driver.
https://www.corvetteforum.com/forums...post1574918379
http://corvettephotographs.com/c4vettes/codes.htm
What they mean (note that the codes changed from year to year so make sure you're looking in the right section):
https://www.corvetteforum.com/forums...post1576116036
You need to determine which quad driver is causing the fault and then investigate the circuits associated with that quad driver.
Thread Starter
Intermediate
Joined: Apr 2014
Posts: 31
Likes: 0
From: Beverly Hills Florida
Just to summarize and make sure I'm understanding correctly, its possible that a relay or solenoid could be at fault, and the quad driver/ECM might be okay?
Edit: Just spoke with the shop, they said it was a quad driver #1 circuit failure, so I assume(based on it being a 1993) a code 26?
Edit: Just spoke with the shop, they said it was a quad driver #1 circuit failure, so I assume(based on it being a 1993) a code 26?
Last edited by triplegriff; Jan 15, 2016 at 09:43 AM.
Burning Brakes
Joined: Mar 2005
Posts: 1,082
Likes: 115
From: Richmond Hill Ontario
Use these links to help you out:
https://www.corvetteforum.com/forums...code-26-a.html
https://www.corvetteforum.com/forums...river-4-a.html
https://www.corvetteforum.com/forums...code-26-a.html
https://www.corvetteforum.com/forums...river-4-a.html
Last edited by FrankieD; Jan 15, 2016 at 12:12 PM.
Thread Starter
Intermediate
Joined: Apr 2014
Posts: 31
Likes: 0
From: Beverly Hills Florida
Oh man, those are awesome, thanks so much!
So reading into them, I am fairly *positive* that the air/smog pump and the EGR(I know the EGR has) have been removed(since Florida doesn't do any sort of emissions testing). SO common sense tells me that these two solenoids should not be throwing the fault since they've been removed, right? Most likely culprit will be the evap canister purge solenoid then, I will check once I get back to the vette and report back.
Thanks again!
So reading into them, I am fairly *positive* that the air/smog pump and the EGR(I know the EGR has) have been removed(since Florida doesn't do any sort of emissions testing). SO common sense tells me that these two solenoids should not be throwing the fault since they've been removed, right? Most likely culprit will be the evap canister purge solenoid then, I will check once I get back to the vette and report back.
Thanks again!
Thread Starter
Intermediate
Joined: Apr 2014
Posts: 31
Likes: 0
From: Beverly Hills Florida
Checked everything above, and couldn't find a fault. Found a remanufactured one via AutoZone... Seems to have eliminated the surging so far.
Because of the EGR and Air/Smog deletes, I am planning to get a tune from PCM of NC, and in order to really get the most of it I would love to get some data logging done to send them. That said, anyone in the North of Tampa/Tampa/Orlando area that would be willing to help me out?
Because of the EGR and Air/Smog deletes, I am planning to get a tune from PCM of NC, and in order to really get the most of it I would love to get some data logging done to send them. That said, anyone in the North of Tampa/Tampa/Orlando area that would be willing to help me out?
Team Owner
Joined: Sep 2003
Posts: 25,331
Likes: 2,722
Checked everything above, and couldn't find a fault. Found a remanufactured one via AutoZone... Seems to have eliminated the surging so far.
Because of the EGR and Air/Smog deletes, I am planning to get a tune from PCM of NC, and in order to really get the most of it I would love to get some data logging done to send them. That said, anyone in the North of Tampa/Tampa/Orlando area that would be willing to help me out?
Because of the EGR and Air/Smog deletes, I am planning to get a tune from PCM of NC, and in order to really get the most of it I would love to get some data logging done to send them. That said, anyone in the North of Tampa/Tampa/Orlando area that would be willing to help me out?
If replacement of the ECM and using your OE/GM PROM I'd suggest you just leave it alone. There's NO WAY I'd surrender my OE/GM PROM to any "tuner". The OE/GM PROMS have significant value currently and regardless of the "tuner" you chose the temptation to substitute something "other than" yours back to you is very great.
You might check your PROM for the ID that should be visible through the window of the blue cover. Generally the 8 digit part # is present also.
I'm not questioning your tuner of choice but it's an observation made from many that have sought out "mail order" tunes. Just forget it and enjoy a good running car. Some tunes are substantially worse than what the original was/is. Maybe shop for a used PROM (correct ID) and use it never giving up or modifying your "original".
Drifting
Joined: May 2007
Posts: 1,426
Likes: 165
From: Motor City
If replacement of the ECM and using your OE/GM PROM I'd suggest you just leave it alone. There's NO WAY I'd surrender my OE/GM PROM to any "tuner". The OE/GM PROMS have significant value currently and regardless of the "tuner" you chose the temptation to substitute something "other than" yours back to you is very great.
You might check your PROM for the ID that should be visible through the window of the blue cover. Generally the 8 digit part # is present also.
I'm not questioning your tuner of choice but it's an observation made from many that have sought out "mail order" tunes. Just forget it and enjoy a good running car. Some tunes are substantially worse than what the original was/is. Maybe shop for a used PROM (correct ID) and use it never giving up or modifying your "original".
You might check your PROM for the ID that should be visible through the window of the blue cover. Generally the 8 digit part # is present also.
I'm not questioning your tuner of choice but it's an observation made from many that have sought out "mail order" tunes. Just forget it and enjoy a good running car. Some tunes are substantially worse than what the original was/is. Maybe shop for a used PROM (correct ID) and use it never giving up or modifying your "original".
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Team Owner
Joined: Sep 2003
Posts: 25,331
Likes: 2,722
That's very dependent on what you're doing/buying. If a person is buying "you're mentioned" package yes, if a person was to want a "real tune" on quality hardware they need your PROM. I'll stick with my comments .....................