What Sensor Is Triggering The Cel?

[sheepscloth]

Hi Guys

Maybe one of you can help me?

A while ago the air pump for the air injection system broke. It kept burning the 50A fuse, which triggered the CEL + disabled VSC and traction control.

Therefore I took the airpump apart and found that it was stuck and the coils totally burned out.

I then simply disconnected the airpump motor and cleared the CEL with my OBD2 reader.

After a couple of days I got the CEL again.

The fuse doesn't burn anymore so I can simply clear the CEL again and wait 2-4days until it triggers again.

Obviously it is annoying having to clear the CEL all the time.

Therefore I would like to know: what signal or sensor that triggers the CEL? Is it the Lambda sensor?

Once I know the signal that triggers the ECU I should be able to do something about it?

What buggers me is that it is not instant but comes on after a couple of days driving, so maybe it is a build up of values/readings that triggers once it reaches a certain level??

Please help me!

And please don't just suggest buying a new airpump, that is too easy.

[nrgizerbunny]

it's the primary lambda sensor that triggers it.

You need to feed it with a high O2 signal (ie lean) for about 2-3 minutes then your problem will go away.

It's actually pretty straightforward to fool.

[Uber_Luke]

Im thinking of removing mine to make space for an induction kit, how straighforward is it?

[sheepscloth]

it's the primary lambda sensor that triggers it.

You need to feed it with a high O2 signal (ie lean) for about 2-3 minutes then your problem will go away.

It's actually pretty straightforward to fool.

Thanks dude.

Can you be a bit more specific than "straight forward"?

Do I need to make a O2 simulator circuit like this?: http://www.mkiv.com/techarticles/oxygen_sensor_simulator/

I am after a permanent fix that I can install and then forget about it

[nrgizerbunny]

you need the signal to resemble a sine wave. about 1 cycle every 2-3 seconds should do it.

That circuit could do with a voltage regulator and then problem solved

[sheepscloth]

OK

I will give it a go some day.

Is a circuit like this the only way to fool the ECU?

Also Can you explain why the CEL doesn't come on immediately, but after 3-5 days of driving?

[nrgizerbunny]

If the coolant temperature is hot, the air pump will not come on because it assumes the cat is hot.

It registers a fault pending, then requires two more faults before it will give the CEL.

[sheepscloth]

Found this thread.

http://www.s10forum.com/forum/f89/do-it-yourself-o2-simulator-126774/

question now: would this simple mechanical fix of moving the O2 sensor backwards work for my problem?