85 And 87 Error Codes In 1991 V2500 Suburban

Blackbart · July 22, 2008

Hello All,

I just found this forum and thought I would post this question for the knowledgeable group here.

I have a 1991 Suburban that just experienced a problem I can't solve....yet.

I was towing a camper going smoothly then a loud backfire/crackle and the engine died...dead.

The engine cranks fine but no fuel or spark. It tripped the 85 and 87 codes which indicate an eprom and eeprom failure. I replaced the eprom with a new one and no dice...same thing...dead..no fuel or spark.

So, do I need to replace the ECM? I am unsure as to how the eeprom works, and suspect it is intergral to the ECM but don't know.

Any advise or suggestions would be much appreciated.

Thanks!!

Bob

Blackbart · July 25, 2008

Well, I guess I will selfishly bump this to the top.

Also, I would pose a simple question.

If you were to get the 87 Error code, which indicated an EEPROM error, does this necessarily mean that the ECM has failed, or may there be another reason for tripping this code?

Thanks!

Bob

minibike132 · July 28, 2008

In 91 codes for memcal or ecm's being faulty were 51,52,53 and 55. Codes 85 and 87 were for transmissions so we would need to know what trans you have to start off. After that I am not a trans guy so I might not be much help but the reason you may not be getting responses is that in 98 all manuals for GM went online and most of us have long since put our books in the basement. I know most techs shudder when anything that old comes in if we might have to dig out the books. Anyway it looks like whatever trans you have 85 is for undefinded gear ratio and 87 is for shift solenoid "B" stuck off.

Edit: doh stupid me, I focused on the 85/87 codes and ignored your no start. Those codes are incidental and probably have nothing to do with a nostart. If I get a chance later I'll dig out a book.

minibike132 · July 28, 2008

To verify, you have no spark and no fuel. But do you not have fuel being delivered to the injectors or do you have fuel pressure at the injectors but they are not firing? If that is the case and you want a shot in the dark part to throw at it go for ignition module.