Hi, Help needed

I currently have some problems with a sensor/sensors on my Legacy turbo and I have to go to the Subaru garage to get the Fault codes out of the ECU as I want to work out what has failed rather than change them all.

Is there any way that I can do this at home? I have a laptop and can make up any neccesary leads. I guess hyper terminal may do for the comms software???

Thanks in advance for all your expert knowledge

 

What year car? I might be able to help.

 

1993 2.0 Turbo

 

With a bit of luck, I have some software for this car.

Have you done the fault code reading with the check engine light?
There's instructions on Chris Palmer's website.
here

The black and green connectors are lurking near the steering column under the dash, along with the yellow connector for plugging the laptop into.

For the laptop bit, you'll need to make or otherwise acquire a RS232 to TTL converter and a means of communicating with the ECU at a non standard baud rate. I can supply the above, but you may not need it if the black and green connectors turn up the problem.

 

Thanks for the excellent information.

I will try the check engine light thing tonight but as I have at no time had the check engine light on except when the ignition is on and the engine is off I am not too confident that there will be any fault codes?

 

You're right - there will probably not be any current fault codes stored.

My software is kind of like a Deltadash for the older cars.

You can use it for getting readings for most of the sensors (will post up a list from home) however it doesn't (yet) do any better than connecting the green and black terminals for getting fault codes.

What are the symptoms?

 

At random times driving becomes like playing a computer game with the key board, the car goes to a very slow and rough idle at anything below 1/2 throttle, anything above 1/2 throttle is just that, full chat. Just like driving a Kangaroo.

Also on two occasions it has been hard to start when cold and damp.

 

Woulds suggest your coil packs / sparkplugs need replacing, mate.

 

I'd check the throttle position sensor as well. It's possible to do this with a multimeter.

 

Changed my plugs just a few weeks back with the NGK platinum ones that are recommend by Subaru (at £12 each!), this made no difference.

I have 4 coils on mine, the can't all play up at once can they? Doesn't seem like it is running on three or anything like that.

What (resistances I guess) do I check for on the TPS?

 

It's easier to check for the voltages on the TPS. From memory it should be 4.7V on idle and 1V on WOT. (You can do this with the engine off, but the ignition on.

Have a look at the following PDF for some more clues.

http://www.jimclarkeracing.co.uk/~sc...iagnostics.pdf

 

Thanks,

Excellent link, looks like my multi-meter will be busy!

Will report back when I complete my diagnosis before spending any dosh!

 

also check the battery terminals are tight and check the engine ground..

David

 

Good idea,

That's easy done, I have it in my mind that I have an earth strap on the gearbox the other end of which is swinging in mid air! Will investigate in more detail.

 

Help,

Tried last night to do the engine check light flashing thing.

Took the panel off under the steering wheel, there are 2 green connectors tucked up above the steering column which I am pretty sure are the ones to do the reset.

There was a pair of black connectors hanging down to the left with the connectors that I believe Subaru plug there kit into (a big yellow connector and a bigger black one). One of the pair has a black and red wire the other a black and brown. I guess this is the correct connector for the read memory mode but when I plugged this and turned the ignition on all that happened was the check engine light came on solid as normal. I understood that even if there were no error codes it should do the OK .5sec flash???

Any Ideas????? All I can think is that I had the door open but surely that wouldn't make any difference!