1G Four codes! Barometric, coolant, air temp...

[lilbacha]

I have a 90 AWD, and here's the issue. If I don't start my car for a day it takes at least 10 times to crank the car and another 5 times to stay on.

When it stays on I get the following four codes:

12 air flow sensor
13 air temperature sensor
21 coolant temp sensor
25 barometric pressure sensor

I thought my MAS was bad, I replaced it and the results weren't any better. I took out my ECU and opened it up, everything checks out okay there as well. My Radiator fan wasn't working recently so I replaced it along with a radiator fan switch and that worked for a day. Now the fan only kicks on when I turn it on manually by pushing the AC button and flipping the switch. Otherwise it begins to overheat.

I have No idea whats going on and any comments will really help...

Also, my coolant temp is reading 95-100 when the needle is dead center

 

[knochgoon24]

12, 13, & 25 are all part of the MAF sensor. Are you sure you replaced it with a good one?

21 is coolant temp sensor to the ECU. It's a pretty cheap part, so just replace it with an ew one.

The only other thing that might be bad is your sensor ground inside the ECU. Did you do any wiring lately? It might not be completely gone, but it may be damaged.

http://www.dsmlink.com/wiki/blownsensorground
http://www.dsmtuners.com/forums/newbie-forum/374858-ecu-ground-sensor-blown.html

 

[lilbacha]

I haven't done any wiring recently. I just took out the ECU and examined it back to front.

Thanks for the quick response!

 

[donniekak]

I haven't done any wiring recently. I just took out the ECU and examined it back to front.

Thanks for the quick response!

By examined i take it you used a dmm to check all of the connections for bad traces. Some of your problems can be caused by acid damage in hard to see areas of the ecu.

 

[lilbacha]

I had also hooked up an EPROM ECU to it and it gave my the same problems of hard starting

 

[jrdrew5]

i throw 13# and my car runs fine i just keep the sensor unplugged so my fans stay on all the time till i get the time to replace it,

 

[lilbacha]

i just bought a coolant temp sensor hoping to fix one of the problems, we'll see what happens

I traced the wiring harness for the MAS to the ECU and it seems to be just fine.