Error 51
Thread Starter
7th Gear
Joined: May 2002
Posts: 7
Likes: 0
From: Stanwood WA
Error 51
My dads car keeps dying on him(88 AT L98, 17k mileage), the OBD system told me error 51, PROM error, and I read that it is a faulty or incorrect PROM. Well, I bought an Ed Wright/Fast Chip PROM which came today, plugged it into the ECU and it gets even worse. Under normal driving the car has all the power it should (even more w/ the new PROM), but it will just die. The RPMs drop like a rock, no gas or anything can keep it alive. Seems to happen at Low RPMs mostly. The car starts just fine again sometimes, other times it takes a bit, and sometimes it will die right afterwards.
The Fuel Pressure is just fine (check it for giggles) at ~35 at idle, jumps up to low to mid 40s when I rev it then drops right back down to 35, steady at 42 PSI when the FPR is unplugged, so it isn't a fuel issue (which I had already guessed).
Is the actual ECU bad? Can anyone shed more light on this issue?
Thanks!
Douglas
The Fuel Pressure is just fine (check it for giggles) at ~35 at idle, jumps up to low to mid 40s when I rev it then drops right back down to 35, steady at 42 PSI when the FPR is unplugged, so it isn't a fuel issue (which I had already guessed).
Is the actual ECU bad? Can anyone shed more light on this issue?
Thanks!
Douglas
Instructor
Joined: Jan 2002
Posts: 111
Likes: 0
From: Reno NV
Re: Error 51 (Evoluzione)
Error Code 51= Faulty EPROM, MEM-CAL, or ECM.
I replaced my 89's ECM about a month ago, $79.95 @ Autozone for a re-man unit. I'd try that first, there are (I think) 4 quad-Driver IC's in the XXX167 ECM which command/power Selenoids, Sensors, IAC. If you have a faulty Sensor or a [semi]-short circuit some where going to/from the ECM it can damage or at least degrade operation of the other 3 Channels of the same respective Quad-Driver IC.
:crazy:NanoBrain:crazy:
[Modified by NanoBrain, 8:40 AM 10/18/2002]
I replaced my 89's ECM about a month ago, $79.95 @ Autozone for a re-man unit. I'd try that first, there are (I think) 4 quad-Driver IC's in the XXX167 ECM which command/power Selenoids, Sensors, IAC. If you have a faulty Sensor or a [semi]-short circuit some where going to/from the ECM it can damage or at least degrade operation of the other 3 Channels of the same respective Quad-Driver IC.
:crazy:NanoBrain:crazy:
[Modified by NanoBrain, 8:40 AM 10/18/2002]
