Hey y'all -

 

I'm trying to get my new EA82T 88GL Turbo back on the road but some electrical issues are preventing that. It was showing a lot of historical codes but the one that seems to be the big one is the airflow sensor / Hotwire MAF.

 

The reason I say that is that the car starts and idles fine with it disconnected, but dies when it is connected. Using the factory manual I think I have traced this to unusually high resistance on the B terminal, which is the connection between the MAF and the ECU. According to the factory manual, resistance between here and ground here should be less than 10 ohm but has ranged between 51-90 ohm. Resistance along the line itself to the ECU is less than 1 ohm, so the issue appears to be internal to the ECU, between that pin (#5) and ground.

 

Although the factory manual says replace ECU, I wonder if someone knows where I can find the actual grounding point for the ECU wires? I'd like to clean that up before I'm sure the ECU itself is hosed - after all, the thing seems to work for the most part, whereas I expected more of a total failure mode...

 

Other ideas are welcome - I have already cleaned up the grounds that I know, including

 

- battery to transmission (2 gauge)

- transmission to body (new 2 gauge)

- harness to intake

 

I've also added a grounding wire between the body and intake (10ga) - however these all seem to be unrelated as it is only the ECU pin 5 to ground circuit where I am seeing resistance numbers.

sounds like youve done all you can ...make sure your ecu itself is grounded ,and thats about all you can do..the ecu should be checked ,by way of fitting another from a friends car(the same models) or simular..and see what you get..good luck...

Yeah, I swapped out the ECU with a similar model from a local junkyard (CA Auto Turbo AA480 vs 49-State Manual Turbo AA410) and so far so good.

 

Resistance appeared lower although still over 10ohm (I think it was reading 18ohm). I drove around the neighborhood for about 30 mins and all was good but the true test is tomorrow when I drive ~100 miles with it - hopefully don't end up stranded somewhere ridiculous...

 

I still haven't figured out where in particular the ECU grounds itself, although suppose it could be through the casing itself.

My manual shows that pins 56,57,60, and 61 of the ECU all tie to ground up by the radiator.

...make sure your ecu itself is grounded ...

 

Do you mean the ECU body itself has to be grounded? as in the external casing.

My manual shows that pins 56,57,60, and 61 of the ECU all tie to ground up by the radiator.

 

Hmm, thanks cougar - that's one I didn't check on. I'll take a look and clean up that ground point...

Your welcome.