Trying to extract ECU error codes
 

I've searched the intertubes, read various forums, read the How To and still can't work out how to obtain error codes from my ECU.
When driving on a long journey the check engine light will fairly regularly appear around 70km from the start of the journey. I suspect a vehicle speed sensor fault, but I want to confirm this before trying to fix it.
There appears to be no adverse effect on vehicle running but I'm planning further work (install of remote starter, alarm & Quick Change) and would like to ensure the car is error code free before introducing new variables.

I've attached a pic which is fairly self explanatory. I guess I need some help identifying the wires I've found behind the kick panel and confirmation that I'm plugged stuff in correctly to obtain the codes.

In case it's relevant, see my other thread about a key barrel fault preventing the key being turned to the lock position.

I also have an ECU Tune cable here (borrowed from Daniel) and Evo Scan software. I mentioned that in case that could be used to extract the engine codes.

Re: Trying to extract ECU error codes
 

Have you read this? http://www.subaru-svx.net/forum/showthread.php?t=54033

Re: Trying to extract ECU error codes
 

yes.
Problems are :
I can only find one blue wire, but the How To seems to refer to more than one blue wire.
I've connected the single blue wire into top row, 2nd pin from left and turned key on, dash lights up, but no check engine light flashing on the dash.

Re: Trying to extract ECU error codes
 

Use the two identical blue/black wires with the male ends. It doesn't matter which one goes where. On my '92 they are pale blue but cars from the pacific market may be different.

Re: Trying to extract ECU error codes
 

Got it to work, thank you.
I unplugged the two black wires that connected together perfectly.
Connected one of them to the appropriate pin on the multi pin black connector and set key to On.
Photo attached. That's a bent paperclip you can see linking them together.

Engine Check light is now flashing like a drunken xmas tree.
I've posted a YouTube video of the flashing lights and attached a photo showing the connectors required to get this to work.

Video can be found here :
https://www.youtube.com/watch?v=GPDNU9ZeqOw

I interpret the codes to be : 23, 12 & 37

These are :
23 = abnormal voltage from air flow sensor
12 = abnormal signal from ignition switch (http://www.subaru-svx.net/forum/showthread.php?t=62748)
37 = O2 sensor 2 inoperative

I'll clear the codes now and see what comes back after my 250km round trip tomorrow.
Looks like I'll replace the air flow sensor & O2 sensors

Re: Trying to extract ECU error codes
 

Shane the top connector in the first picture (black wires that plug together) - shorted together = deg C / open circuit = deg F

Re: Trying to extract ECU error codes
 

If the codes you noted are real try to re-solder the MAF first. I just did mine - yesterday it stalled first time ever (after installing the Nissan MAF 2 years ago). It's only a 30 minute job.

If you get a nonsense signal from the MAF your air/fuel ratio might be all over the place and you may get an out of range O2 signal too.

Not saying that your lambda sensor is not bad, just try to fix the MAF first.

/T

Re: Trying to extract ECU error codes
 

I've got a couple of spares, so swapped another MAF in to see what happens.
Also reset the ECU codes and confirmed that it's clear.

Re: Trying to extract ECU error codes
 

I re-soldered mine - idle is silky smooth (again) and the engine runs much better in general !! Even the wideband is much more stable around the stoichiometric ratio.

The engine never missed a beat untill it stalled once yesterday. It had just slowly developed - something. There was nothing visual in the circuits even with a magnifying glass.

/T

Re: Trying to extract ECU error codes
 

I've got about 4 MAFs now, bought some solder, solder wick & sealer today. So I'll disassemble one later today and resolder it, then install and see what happens.

The other thing I'm going to try is to simplify getting codes from the ECU.
Originally I was going to add some switches under the dash which which will short the appropriate connections in order to get check engine light to display codes and then the other switch to clear the ECU.

Had a better idea, another mod I've done is to solder a bridge across the contacts on the Cruise switch (on the dash), so that Cruise control will always be available from the Cruise stick without having to press another button on the dash to get it to work. So, by bridging this a little bit further down in the wiring loom this leaves the Cruise switch sitting on the dash with no purpose.
Right next to it is a Fog lights switch which now no longer has a purpose in my car (car has plastic headlights with fogs fitted, I swapped out the whole headlight units for glass, but our local glass headlight units don't have fogs, so I lost the fogs along the way, no great loss). So that freed up another switch on the dash.

Intention is to wire the fog light switch to cause the CEL to flash error codes and the Cruise switch (which is a momentary action switch) to clear the codes.

Re: Trying to extract ECU error codes
 

Oh dear, don't make this mistake. Glue the lid back on the MAF then realise you've left the copper shield out.

Re: Trying to extract ECU error codes
 

It looked well sealed. Was the sealant dry?

Re: Trying to extract ECU error codes
 

When I first opened it, it was extremely well sealed, no sign of corrosion inside the MAF at all.

If you look very closely at the pic of the inside of the MAF sensor you'll see fine cobwebs across it. It seems MAF cleaner doesn't remove cobwebs (probably just makes them clean) so I had a very gentle poke around with a fine probe to clear the webs.

Re: Trying to extract ECU error codes
 

Completed switch mod to easily pull engine codes by using the (redundant) fog lights switch.

Replaced MAF with spare which was cleaned & resoldered.

Drove 250km round trip with no errors codes from MAF.

Still getting errors 12 & 37
12 Starter Switch or Circuit
37 Oxygen Sensor (No. 2, Left Side, On SVX)

So it looks like I've solved the MAF error.

I've booked an automotive locksmith to swap the ignition switch tomorrow with my spare (he's familiar with correct procedure to remove the headless bolts).
That should cure error 12, perhaps.

That just leaves the oxy sensor. I'll clear the codes and go for another drive just in case it needed to blow some crap of the pipes (vainly hopeful).

Re: Trying to extract ECU error codes
 

As I posted earlier I got code 12 twice, but only when in P or N. Strange idle fluctuation when the light was on. Shift to D or any other position and the problems vanished. I thought it was the granny switch, but has not been able to repeat for diagnosis.

T