[bluebronco69]

Hi all.
i have a 99 ZX2 and the fuel pump and electric radiator fan will constantly run, even with the key off.
i have disconnected the battery to solve this for now....

here is what i have done so far.

1)cleaned all grounds (battery post, engine, body, and frame)
2)replaced the CCRM (relay module under the air filter)
3)disconnected the fuel pump (the fan kept running)
4)disconnected the fan (the fuel pump kept running)
5)disconnected the fuel modulating box in the trunk (fan keeps running)
6)unplugged the ignition switch (fuel pump and fan keep running)
7)disconnected the fuel injection relay (under hood and under the dash) this stops the fan (and of course the pump...) so my problem is somewhere in the fuel injection system..???

what could these have in common? the PO replaced the fuel pump, but because of 3 - i dont think the pump is the problem...??? also, the problem isnt there everytime...maybe 1 in 3 times you shut the car off. but it can come back whenever the battery is connected...

any ideas? thoughts? i also unplugged the PCM and reseated the connector...same issue still existed.

one weird part is this:
i have a pinout for the CCRM:
https://goo.gl/images/zrG7Fy

and the 5 that are supposed to be hot at all times were not. there was not 12 V at those pins. pin 15 (ground) was good for continuity though

 

[brrc]

Did you solve the problem ???

 

[bluebronco69]

Nope.
Took the pcm and found some burnt capacitors. Replaced the pcm. Didn't solve the issue.
Found that when I unplugged the oxygen sensor the fuel pump and fan stop. Tried replacing the oxygen sensor and no,change. I also get code p0135 but not sure why...
Read something about a oxygen sensor ground to the power steering pump...haven't investigated that yet though.

The issue now reliably goes away if I shut off the car, then turn the key back to on. Then turn the key off.
So still searching

 

[bluebronco69]

Ccrm

 

[pextor]

Is that what the problem was - the CCRM? makes sense, as that's where all the relays are for the fans and pumps and whatnot.

 

[marclar]

ccrn controls the fan relays. the microprocessor most likely failed and backfed power back to the pcm.