Hello - I would be grateful for any good suggestions as to how to fix this problem on my 91 C2 964 Tip Tronic.

I had disconnected my car battery whilst away on holiday for a fortnight. Then reconnected it last week, drove 40 miles with no problems.

On Monday this week I started it up and the abs light came on with the beeper before I pulled away. Turned off, restarted, the abs light came back on. I set off and the light went off. Then I pulled to a stop at the traffic lights and the abs light came back on with the beeper.

I then set off and noticed the speedo was not working.

The next day I had the same problem but with the spoiler light on. Then I noticed the tip-tronic function was not working.

The Adrian Streather manual says these symptoms on this model will be either the ABS unit or a wheel abs sensor.

I have read a number of threads on the website. Comments range from a faulty relay no.34 in the fuesbox, bad earth connections in the front boot, faulty wheel abs sensors.... However, I have not come across a thread which describes the symptoms all together as I have stated.

The car is dry stored, there is no damp in the boot, it is well looked after at 108K miles.

I hope its not the abs unit as I guess these are expensive.

Any helpful comments would be appreciated.

Regards
JC

 

I had all these issues except I have a manual (so obviously no tip). ABS relay was starting to go bad so issues were sporadic at first. The new relay was like 100 IIRC. Plugged it in and it worked like a charm. I think the ABS units are pretty solid. Is the odometer working?

 

Thanks for your reply. No the odometer does not work. I tried removing the relay and bridging the connection but it made no difference.

I recently jump started the car and a specialist said that this can sometimes finish off old relays as a voltage surge blows the diodes. If this is what happened it did not finish off the relay immediately. I guess I will have to try test the relay itself / try a new one.

 

PS The relay rattles, which is a bit strange I guess.

 

I would start by determining if the ABS is functioning properly as it provides the speed signal to the speedometer. Next I would look at the speedometer which provides the output signal to the spoiler. However, since you mention the tip is not functioning properly, I believe the issue lies within the ABS system itself. Check for power on the ABS controller connector.