Problem with Entering Service or Diagnostic Mode

[Rusty Wishbone]

My Elan hasn't been running correctly since it came back from its cambelt change, so I thought that I would check the base timing. How hard can that be?

Well, I got the car up to temperature, and while running the engine, put the paperclip into pins A&B of the ALDL plug. The engine changed its note a little, so I assumed that it had entered the service mode. However, the CEL did not flash. I proceeded to check the timing and it was at about 5Deg, not 16. Twisting the CAS towards the 16Deg point causes the engine to start hunting, so that can't be right. So I wondered if the engine was, in fact, in service mode at all.

Next, I tried to put the engine in diagnostic mode, starting with the ignition switched on, but the engine off. Still no CEL flashing. However, it does trigger a whirring noise from within or beneath the plenum.

So, my question is, why isn't the engine entering service/diagnostic mode, or if it is, why isn't the CEL light working.

I did have a journey about a week ago where the CEL light came on for most of the journey, but it hasn't come on again since. I don't know if this is relevant.

[Rusty Wishbone]

Having moved the timing closer to the 16 deg mark has made the car run much better. It pulls cleanly through 4000 RPM, which it wasn't doing. So, perhaps the CEL bulb has blown. It doesn't come on when I turn the ignition on.

While it pulls well now, the turbo only boosts to 0.5bar. Since it has an Everest chip, it should be boosting more than that. I'll replace the CEL bulb and see if there are any error codes which might indicate a problem.

[Ian T]

Did you fix this, Rusty?

[Rusty Wishbone]

No progress on this, I'm afraid. I don't really know where to start. The CEL isn't illuminating when I drive the car, and the car runs pretty well. I still don't think it pulls as well as it should below 4000rpm, but it is turbocharged, so I suppose that it should take off when it hits some engine speed.

[CalElan]

does the CEL come on with the other ignition lights before you start the car?

[Rusty Wishbone]

No, it doesn't come on when I first turn the ignition on.


It sounds like you are onto something.


I have no idea what.

[CalElan]

me either - but it sounds like a blown bulb. The sound you were getting when you put the car into service mode without engine running is what I expect to hear.