Need help with ECM 1986
Thread Starter
Melting Slicks
Joined: Nov 2007
Posts: 2,830
Likes: 147
From: Gainesville FL
Need help with ECM 1986
I have a code41 problem. No help in tech section since this is an ECM related question I thought I'd ask in here.
How does one get at the ECM in an 1986 (see previous post for more details)
http://forums.corvetteforum.com/c4-t...t-86-vert.html
Thanks in advance
How does one get at the ECM in an 1986 (see previous post for more details)
http://forums.corvetteforum.com/c4-t...t-86-vert.html
Thanks in advance
Safety Car
Joined: Sep 2001
Posts: 4,165
Likes: 555
From: Glenbeulah Wi
It is behind the dash pad on the passanger side of the car. You get at it from the bottom. Remove the black plastic underside dash cover and it is bolted up in place behind the dash pad. Two 10mm bolts hold it in place.
Thread Starter
Melting Slicks
Joined: Nov 2007
Posts: 2,830
Likes: 147
From: Gainesville FL
Where can you buy OEM PROMs 1986
I've traded out my ECM and that wasn't the issue with my code 41. None of the ECM's come with PROM's and I've already got a hypertech prom in the ECM I have now.
I suspect it's the problem but I'd rather put back in and OEM PROM.
WTB even someones old OEM prom for and 1986.
???
I suspect it's the problem but I'd rather put back in and OEM PROM.
WTB even someones old OEM prom for and 1986.
???
Burning Brakes
Joined: Apr 2004
Posts: 762
Likes: 2
From: Huntington ma
Can't help with a 1986 PROM, but I can offer this..
A code 41 is pretty simple, and specific. If a replacement ECM didn't cure it the problem about Has to be a faulty ground or open circuit for the ECM cylinder select (pin D3 on an '85 and I Think it's the same for the '86 - only a few of the pins change). Nothing else to it.
The only other even Remote possibility would be something wrong with the pickup coil, providing a goofy number of reference pulses to the ECM - but That would be causing other things to go haywire as well, a code 41 would be the Least of your problems.
Hmmm - there IS a setting in the PROM program for "number of cylinders", which I suppose Could be messed up in your Hypertec chip. I'd say Unlikely, but possible. If so that Could explain the code 41, but it would have had to have Been like that right along - since the chip was brand new. I don't think I've ever seen a PROM chip "die", or loose memory or something like that.
A code 41 is pretty simple, and specific. If a replacement ECM didn't cure it the problem about Has to be a faulty ground or open circuit for the ECM cylinder select (pin D3 on an '85 and I Think it's the same for the '86 - only a few of the pins change). Nothing else to it.
The only other even Remote possibility would be something wrong with the pickup coil, providing a goofy number of reference pulses to the ECM - but That would be causing other things to go haywire as well, a code 41 would be the Least of your problems.
Hmmm - there IS a setting in the PROM program for "number of cylinders", which I suppose Could be messed up in your Hypertec chip. I'd say Unlikely, but possible. If so that Could explain the code 41, but it would have had to have Been like that right along - since the chip was brand new. I don't think I've ever seen a PROM chip "die", or loose memory or something like that.
Thread Starter
Melting Slicks
Joined: Nov 2007
Posts: 2,830
Likes: 147
From: Gainesville FL
That's what the troubleshooting points to
Can't help with a 1986 PROM, but I can offer this..
A code 41 is pretty simple, and specific. If a replacement ECM didn't cure it the problem about Has to be a faulty ground or open circuit for the ECM cylinder select (pin D3 on an '85 and I Think it's the same for the '86 - only a few of the pins change). Nothing else to it.
The only other even Remote possibility would be something wrong with the pickup coil, providing a goofy number of reference pulses to the ECM - but That would be causing other things to go haywire as well, a code 41 would be the Least of your problems.
Hmmm - there IS a setting in the PROM program for "number of cylinders", which I suppose Could be messed up in your Hypertec chip. I'd say Unlikely, but possible. If so that Could explain the code 41, but it would have had to have Been like that right along - since the chip was brand new. I don't think I've ever seen a PROM chip "die", or loose memory or something like that.
A code 41 is pretty simple, and specific. If a replacement ECM didn't cure it the problem about Has to be a faulty ground or open circuit for the ECM cylinder select (pin D3 on an '85 and I Think it's the same for the '86 - only a few of the pins change). Nothing else to it.
The only other even Remote possibility would be something wrong with the pickup coil, providing a goofy number of reference pulses to the ECM - but That would be causing other things to go haywire as well, a code 41 would be the Least of your problems.
Hmmm - there IS a setting in the PROM program for "number of cylinders", which I suppose Could be messed up in your Hypertec chip. I'd say Unlikely, but possible. If so that Could explain the code 41, but it would have had to have Been like that right along - since the chip was brand new. I don't think I've ever seen a PROM chip "die", or loose memory or something like that.
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From: Freedom is never more than one generation away from extinction.
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http://www.cruzers.com/~ludis/p4xref.html
Here were a pretty good list of memcals codes exist.
I have a custom tune for my 86e Auto you could try. (jrriflecoach@gmail.com)
Remember that the batt is disconnected when swapping memcals.
Here were a pretty good list of memcals codes exist.
I have a custom tune for my 86e Auto you could try. (jrriflecoach@gmail.com)
Remember that the batt is disconnected when swapping memcals.
