ecm troubles?
Thread Starter
Burning Brakes
Joined: Apr 2009
Posts: 1,228
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From: That one city...you know that one. Idaho
ecm troubles?
Sometimes when i am driving my vette the sys/security will flash, other times it will be the service asr/ses light that is on, and sometime both. When I check for error codes (paper clip) about 50% of time I get nothing the other 50% I get Err from the ECM. The CCM also had codes 41, 54, and 72.
Now for what i have done.
I turned off vats in the ECM.
I checked pin m on the dlc connector for a short, it apears to be shorted to B+ when the ECM is pluged in.
If I need to check anything else let me know as I am not sure this is the ECM.
Now for what i have done.
I turned off vats in the ECM.
I checked pin m on the dlc connector for a short, it apears to be shorted to B+ when the ECM is pluged in.
If I need to check anything else let me know as I am not sure this is the ECM.
Thread Starter
Burning Brakes
Joined: Apr 2009
Posts: 1,228
Likes: 10
From: That one city...you know that one. Idaho
All the grounds i could see look fine. With the computer unhooked pin M is no longer shorted to B+. Also if i tap the computer in a specific spot the car dies.
Thread Starter
Burning Brakes
Joined: Apr 2009
Posts: 1,228
Likes: 10
From: That one city...you know that one. Idaho
the only thing i know for sure about the problem is it is temperature related. I have replaced the battery and ecm at this point.
no change.
Few questions
1. what happens if the injector driver gets overloaded?
2. what are the ohm specs for the injectors on a 1993 corvette
3. what does the ccm do/control
4. What is needed to put in a TPI ECM/Distributor and remove the LT1 ECM, I know i will loose the factory speedo/gauges
5. what about 24x conversion and remove the LT1 ECM.
6. if i decide to use 2 or 3 and not fix as is can i remove the ccm?
cold ohms
8=~13.8 7=~14.5
6=~14.5 5=~14.5
4=~14.5 3=~14.5
2=~14.5 1=~14.5
no change.
Few questions
1. what happens if the injector driver gets overloaded?
2. what are the ohm specs for the injectors on a 1993 corvette
3. what does the ccm do/control
4. What is needed to put in a TPI ECM/Distributor and remove the LT1 ECM, I know i will loose the factory speedo/gauges
5. what about 24x conversion and remove the LT1 ECM.
6. if i decide to use 2 or 3 and not fix as is can i remove the ccm?
cold ohms
8=~13.8 7=~14.5
6=~14.5 5=~14.5
4=~14.5 3=~14.5
2=~14.5 1=~14.5
Race Director
Joined: Nov 2003
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From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
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If it hasn't changed from 89 to 94, sys/security flashes when the door is open. It can flash when close -- IF -- the door switch is misadjusted or problematic. I believe the door switch near the latch is the one(s) you should check. The switch at the front of the jam controls the courtesy lights.
These switches are on both doors.
Since I don't have the ASR option, I can't help with that.
These switches are on both doors.
Since I don't have the ASR option, I can't help with that.
Thread Starter
Burning Brakes
Joined: Apr 2009
Posts: 1,228
Likes: 10
From: That one city...you know that one. Idaho
I forgot to add, that yesterday I found that ccm fuse #2 was bad so I replaced it.
also
I now know it is pretty much.
after about 35-50 minutes of driving the Service ASR/SES is on and Security Light flashes. The SYS light is probably also flashing (not sure there aftermarket radio, need to add resitors). Last time this happened I put a bag of ice on the computer for a while and let it chill but the lights did not turn off until I disconnected the battery. If I disconnected an reconnect the battery without putting ice on the computer most of the time it will restart but the lights will still be on.
also
Sometimes when i am driving my vette the sys/security will flash, other times it will be the service asr/ses light that is on, and sometime both.
after about 35-50 minutes of driving the Service ASR/SES is on and Security Light flashes. The SYS light is probably also flashing (not sure there aftermarket radio, need to add resitors). Last time this happened I put a bag of ice on the computer for a while and let it chill but the lights did not turn off until I disconnected the battery. If I disconnected an reconnect the battery without putting ice on the computer most of the time it will restart but the lights will still be on.
Thread Starter
Burning Brakes
Joined: Apr 2009
Posts: 1,228
Likes: 10
From: That one city...you know that one. Idaho
when the digital temp gauge read ~120
the ohms were
8~20 7~60
6~20 5~60
4~30 3~60
2~30 1~80
that does not seem right.
also what happens if the injector driver overloads?
the ohms were
8~20 7~60
6~20 5~60
4~30 3~60
2~30 1~80
that does not seem right.
also what happens if the injector driver overloads?
Last edited by aDigitalPhantom; Aug 31, 2011 at 12:04 PM.
Race Director
Joined: Nov 2003
Posts: 12,220
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From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
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That said, I would be suspicious of injector connector readings with that much disparity.
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Thread Starter
Burning Brakes
Joined: Apr 2009
Posts: 1,228
Likes: 10
From: That one city...you know that one. Idaho
I think I found the real reason behind all of the gremlins. the charging system. when I was driving it today I had a multimeter hooked up to the cigarette lighter and it got up to 17.4 volts before I got home. This is with a new reman alternator. Ok don't ask me why I checked the charging system but i did and replaced the alternator the old one on a test bench was at 19.5 volts.
Any ideas as to why an alternator would do that?
Any ideas as to why an alternator would do that?
Race Director
Joined: Nov 2003
Posts: 12,220
Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
I think I found the real reason behind all of the gremlins. the charging system. when I was driving it today I had a multimeter hooked up to the cigarette lighter and it got up to 17.4 volts before I got home. This is with a new reman alternator. Ok don't ask me why I checked the charging system but i did and replaced the alternator the old one on a test bench was at 19.5 volts.
Any ideas as to why an alternator would do that?
Any ideas as to why an alternator would do that?
Without a properly functioning regulator, you'd see external and internal lights getting brighter/dimmer.
Injector pulse width is also based on (and is adjusted by) a table dictating how they should react vs Voltage. Systems without a functioning regulator could because a bit more irratically rollling down the road...or idling. Possibly starting too.
Melting Slicks
Joined: Nov 2008
Posts: 2,765
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I think I found the real reason behind all of the gremlins. the charging system. when I was driving it today I had a multimeter hooked up to the cigarette lighter and it got up to 17.4 volts before I got home. This is with a new reman alternator. Ok don't ask me why I checked the charging system but i did and replaced the alternator the old one on a test bench was at 19.5 volts.
Any ideas as to why an alternator would do that?
Any ideas as to why an alternator would do that?
I have seen it prior too.
Thread Starter
Burning Brakes
Joined: Apr 2009
Posts: 1,228
Likes: 10
From: That one city...you know that one. Idaho
I think my car is possessed. It was fine all day yesterday after changing alternator, but today it is back at it, only not dying. I got a dtc for the first time (yay?) it was #43. I also ask a different mechanic about it and he says optispark.
Race Director
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From: O'Fallon Missouri
Thread Starter
Burning Brakes
Joined: Apr 2009
Posts: 1,228
Likes: 10
From: That one city...you know that one. Idaho
You're gonna love this, but I just found out the negative battery cable has a short in it. So I will replace that and see what happens.
Race Director
Joined: Nov 2003
Posts: 12,220
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From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
OTOH, if there's a loose connection, that's not (technically) a short.
Thread Starter
Burning Brakes
Joined: Apr 2009
Posts: 1,228
Likes: 10
From: That one city...you know that one. Idaho
true. I replaced the loose battery cable end and and drove it about 1-2 miles and now it won't start.
can a memcal fail and still have the prom be good? I have a Moates burn 2, and some SST27SF512 chips that read fine in the burn 2 same thing i programed on them. When i turn the key on the fans turn on and there are a bunch of relays clicking.
can a memcal fail and still have the prom be good? I have a Moates burn 2, and some SST27SF512 chips that read fine in the burn 2 same thing i programed on them. When i turn the key on the fans turn on and there are a bunch of relays clicking.
