[RESOLVED] Coolant temp reads -40*F - other DTC's as well

[99gst_racer]

This all started when I was driving home and my turbo sucked in the O2 sensor wiring. I did a temp roadside fix and limped it home and repaired everything correctly. But since then, the car still hasn't ran correctly. The idle was a bit over 1000 RPMs before, but now it lobes between 400 and 700 RPMs. That is, if it idles. It sometimes dies within seconds.

Well, I did a quick datalog, and my coolant temp is showing -40*F. Also, my cooling fans will not turn off. They come on with the car now (was not like that before, as I am still using the factory relays). And I'm also getting a list of other codes.

I can't make heads or tails of this. Can anyone offer any insight?

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[1992awdlaser]

0110 and 0105 have to do with the maf. If you have a spare one I would swap it and see if it fixes anything. Part of the o2 wiring could have hit the maf wires.

I had the 0115 and it was due to the wiring for the coolant temp sensor being messed up. -40 reading means the sensor is bad or the wiring is messed up.

Maybe the ecu has a default for if the coolant temp sensor goes bad it tells the fans to turn on at all times to prevent overheating.

 

[crimsondragon]

I don't think he has a MAF. Otherwise how else did the wire get sucked into his turbo? Either he has a GM MAF or a stand alone and since that's DSMLink, my guess is on GM MAF.

 

[1992awdlaser]

I don't think he has a MAF. Otherwise how else did the wire get sucked into his turbo? Either he has a GM MAF or a stand alone.

His profile says he has a maft. And I knew he had to have a maf since the screen shot is of dsmlink.

 

[99gst_racer]

Yes, I have a MAFT set-up. I've checked the MAS wiring in the engine bay and everything is just fine.

I also replaced the coolant temp sensor with a known working sensor, and the problems remain.

I'll re-trace all of the wiring again and see if I come up with something. But before that, I'll pull the MAS off of my Grand Prix and throw it on to see if it's a fix.

 

[18gTalon]

Id start by looking at the filament on your MAF and see if debris hit it. If anything hits that the MAF usually takes a dump, giving you your baro and intake temp codes. If you put that MAF in and the solution is still not fixed, I would check to see if you get 5 volts out of pin 83 on your ECU (coolant temp sensor). No power from there...need an ecu, a possible short could have happend when the wiring was sucked in, blowing that part of the ecu. If you do get 5 volts from your ecu, check to see if you get 5 volts at the sensor (black w/white tracer). If you have 5 volts there, check to see if your getting any feedback to ecu (pin 92). I dont know if this alldata link will work cause I had to use my shops password to access it.

ALLDATA Online - Logon

This is the MFI wiring diagrams. If nothing from above tells you whats wrong, I would print them all out, tape them together so the pages connect and you can see where the wires are spliced and what wires are spliced. There's got to be a common denominator somewhere. Good Luck. i hope this info is useful to you.

 

[99gst_racer]

Well, my Grad Prix runs well on both MAS sensors, and the DSM hardly runs on either. I guess we can eliminate that variable.

I'll check the ECU right now.

Thanks!

 

[EagleTSIawd]

that sounds like u blew your ground track on your ECU, its an easy fix if you know how to soder stuff

here is the link how

blownsensorground [ECMTuning - wiki]

 

[99gst_racer]

that sounds like u blew your ground track on your ECU, its an easy fix if you know how to soder stuff

here is the link how

blownsensorground [ECMTuning - wiki]

You, sir, are THE MAN!

I pulled the ECU and found that exact ground track burned and broken. Must have happened when the O2 sensor wiring was chopped up and mingled together.

A big thanks to everyone for their help. I definitely learned something new today.