A little confused as to ecu error...

[Mickroy]

I've search and read alot of related threads, but nothing thats ultra specific to my problem.

I Have a 95' gts-t, and its idle isnt so smooth. Much of the time whilst idling at traffic lights the revs will jump up and down, as if someone is tapping the accelerater (goes from 650rpm to about 900, then back and forth).

Then, I reset the ecu on the weekend to see if it would correct itself, but it didnt. Not only that, but now the car has absolutely no boost! turbo spools, boost guage registers, but theres no boost whatsoever!!

So, Idle fluctuates, & the car goes absolutely nowhere when you put your foot in!

Well today I thought I would run ecu diagnostics to see if could shed any light on this problem. I got error code 13: Coolent temperature circuit. My question is: What does this mean? That the ecu is compensating for the error by rooting around with engine timing or something? I'm a bit lost, as I'm not a huge car person. I'm on the verge of taking it to be looked at. Any input would be greatly appreciated.

Cheers!

[Jay95R33]

It could be a few things.

Could be the coolant sensor has been unplugged so the ECU can't see it. Could be the wires to the sensor are broken or not connecting properly, or maybe the sensor itself is stuffed.

Pretty sure that the coolant sensor for the ECU is where the top radiator hose goes into the motor. You'll see two sensors on the housing, the sensor with one wire is the temp sensor for the gauge cluster, and I *think* the two wired sensor is for the ECU.

J

[Mickroy]

thanks for your input....I will inspect the condition of the plugs/wires tomorrow. Given the error, do you think its reasonably that the car is doing what its doing? Its the strangest thing to hear the turbo freely spooling but not feeling any boost.

[Jay95R33]

Not really sure Mick, I've never had that problem before although cars will do weird things when a sensor is faulty.

I'd say that it should be running pretty rich if the temp sensor is stuffed/disconnected. But like I said, cars do weird things sometimes

J

[RB20LagWagon]

hunting idle is usually a afm problem,(or you installed a wolf ) ecu goes into limp home mode and wont allow revs or boost. Make sure the ecu is plugged in correctly, maybe try and find another afm that you know is good/working to see.

[blind_elk]

thanks for your input....I will inspect the condition of the plugs/wires tomorrow. Given the error, do you think its reasonably that the car is doing what its doing? Its the strangest thing to hear the turbo freely spooling but not feeling any boost.

Yes. The ECU thinks the engine is still cold, and is probably applying a boost cut, because you're not supposed to be thrashing the engine when its cold. The hunting is probably a result of confusion of the ECU because the engine can run quite easily when up to temp, but is being fuelled as if it were cold. It could also be a slightly stuck AAC valve.

On the 2-wire plug Jay95R33 described, check for continuity between one of the wires and pin 28 on the ECU.

[Mickroy]

hmmm....It actually makes sense that the boost only became an issue when I reset the ecu....because, error codes are only meant to stay in the ecu for 50 starts.

Well, at least I have a lead in solving this problem now.

[Mickroy]

plugged a known working coolant sensor into my ecu...same error

[blind_elk]

plugged a known working coolant sensor into my ecu...same error

The 2-pin one? The single pin one is for the temperature gauge in the dashboard.

Have you checked that the wires aren't broken (0 ohms to pin 28 at the ECU)? Have you checked for a recurrence of the error code?

[The Mafia]

dude have you ever considered that your turbo might be stuffed?

I know that its a long shot but it is worth checking...

[Mickroy]

Never thought that for a second....because it only became an issue when I reset the ecu. An ecu error isnt going to let the car run the way it should, and thats the only effect there is on the turbo.

As an update, the temp sensor is fine...as is continuity to the ecu. All voltages check out against the manual. So whats the go? Why error code 13? ...I've also given the AFM a good clean and checked it out against the manual. It too is talking properly to the ecu as far as I can tell. I'm a little lost....could it be the ecu itself?

[japsky33]

Mickroy,

YOur telling us that you can hear the turbo spooling but your boost gauge is reading 0 ? and your experiencing fluctuated idles ?

Check your inlet tract buddy I think you might have blown a pipe off.

BR,

JH

Never thought that for a second....because it only became an issue when I reset the ecu. An ecu error isnt going to let the car run the way it should, and thats the only effect there is on the turbo.

As an update, the temp sensor is fine...as is continuity to the ecu. All voltages check out against the manual. So whats the go? Why error code 13? ...I've also given the AFM a good clean and checked it out against the manual. It too is talking properly to the ecu as far as I can tell. I'm a little lost....could it be the ecu itself?

[Mickroy]

negative. Boost guage works fine, turbo spools fine.

[japsky33]

OK, well ignore my comment then from your last posts I thought you werent getting boost

JH

negative. Boost guage works fine, turbo spools fine.

[Mickroy]

I'm not getting boost...re-read my posts, think i explained my prob reasonably well

[The Mafia]

I'll find some time and come for a ride with you michael, and try and see what is wrong with your line.

Do you have an aftermarket boost guage? Whats it reading?

[japsky33]

You just said again your NOT GETTING BOOST? I didnt say your boost guage wasnt working Im asking you are you getting POSITIVE pressure showing on your gauge ?

I'm trying to help you your problem sounds alot like a leak in your inlet tract.

I have seen temp sensors cause issues with the computer but you said your self you have checked it. Did you check it from the sensor side or inside the car ?

I'm not getting boost...re-read my posts, think i explained my prob reasonably well

[Mickroy]

The guage is working, and i can hear the turbo spooling...but i cant FEEL any boost. There is no go in the car...

I checked everything to do with the sensor, followed the troubleshooting guide in the manual of things to check relating to error code 13, and even plugged a different, known working sensor into my ecu....same error, same issues. The sensor works, is talking fine to the ecu, yet the error and problems persist.

[The Mafia]

where are you going to be this afternoon mick? I shall come for a look.

Call me or MSN me and we'll arrange a meeeting place

[2fardown]

You can hear the turbo spooling but what everyone wants to know, is if the guage is registering any pressure? Are you familiar with reading boost guages?