Crank Angle Sensor/Distributor change not clearing Error Code 4

[Bruce]

With slightly aggressive driving, my Beat is now triggering an error code 4 (Crank Angle Sensor) and going into the sluggish limp home mode.

I believe from one or two forum posts and the wiring diagram that this sensor is part of the distributor. Fortunately, I had kept my old distributor from 7 years ago, which had been replaced probably due to my ECU dying due to leaking capacitors, and thereby probably giving a false error code. I had since replaced the ECU.

So with my suspicion that the old distributor was fine (and also being only about 7 years old) the garage swapped back to the old distributor. Yet disappointingly, the error code 4 remains. I have never had this error code before a few weeks ago, so I don't think the problem is with either distributor.

I had a look at the ECU, and being pretty young, it still looks as good as new.

Can anyone confirm that the crank angle sensor is definitely part of the distributor?

My new suspicion is that the problem is with the wiring, worryingly. Incidentally, This summer my tachometer failed, and unlike several years ago, opening it up and lubricating it did not fix it. I see that the tacho is quite close to the crank angle sensor on the wiring diagram, reinforcing my suspicion that its a wiring problem, maybe one of the earths either side of them on the diagram.

I've also asked the garage to check the sensor resistance is nominal, which they'll do tomorrow.

Can anyone give any more suggestions on things to check to find the problem? Thanks.

[Steve_M]

The crank angle sensor is in the distributor.

I would have initial said about checking that the timing is spot on, but if the distributor has been changed that would surely had an effect on it. e.g. timing checked and adjusted with the service connector bridged.

There are only 2 wires back to the ECU for the Crank Sensor, from the sensor connecter (4pin) at the distributor it goes via the engine harness and only goes through one other connector (14 pin) on the bulkhead before it goes to the ECU.

Resistance of the sensor (800 - 1300 ohms) is first checked at the sensor connector and then at the ECU connectors to check the continuity of the wiring.

Hopefully the attached will help you trace the wiring.

[Steve_M]

Connector pin locations for Crank Angle Sensor

[Bruce]

Thank you again Steve. You've been a great help to all of us over the years.

I’m still suffering this problem, and my MOT is running out soon. The wiring continuity seems OK, I’ve twice swapped between my two 7 year old distributors, so it doesn’t seem to be a timing issue. It might be that both distributors are broken. But I think it’s probably an ECU fault, in spite of its similar 7 year age. But before I send it for repair, I really need to test one that definitely works.

So I need really help from the forum. Does anyone reading this have a working Beat anywhere within say 100 miles of the Bristol/Bath area? I’d be really grateful if we could meet up and briefly try your ECU in my car. I can come to you, any day, ideally before the end of July. And I can move the ECU over and back. It shouldn’t take more than a couple of hours, as the error code can be consistently triggered.

(Incidentally, the error was the top dead centre TDC sensor, not the crank angle sensor. It's more likely I mixed them up than for the code to have changed. Both sensors are in the distributor, so it makes no real difference.)

[Andrew Fisher]

I hope someone can help you but if not (and I'm starting to sound like a broken record here) ECU Doctor have helped lots of Beat owners, eg:

http://www.u-ukhbc.co.uk/vbb/showthread.php?4042-New-owner-with-an-ecu-problem&highlight=doctor

Good luck!

[Bruce]

Yep, the ECU Doctor fixed my problem in the end. Thanks for the tip!

[Andrew Fisher]

Yep, the ECU Doctor fixed my problem in the end. Thanks for the tip!

That's great the ECU Doctor rocks!

[Mobius]

Had same problem and confirmed with the aid of a spare ecu that mine was faulty.

Ecu Doctor rebuilt it and sent it back in a week and all is well now. Apparently 30 years had took a toll on some of the capacitors and put them out of tolerance. This caused fuel injection problems.

Something to think about folks.

[fxdlidon]

So I need really help from the forum. Does anyone reading this have a working Beat anywhere within say 100 miles of the Bristol/Bath area? I’d be really grateful if we could meet up and briefly try your ECU in my car. I can come to you, any day, ideally before the end of July. And I can move the ECU over and back. It shouldn’t take more than a couple of hours, as the error code can be consistently triggered.

I'm in Cardiff, if that's any help, my ecu was rebuilt last year