Firstly, a BIG thanks to Gus at Jagrepair.com for supplying the 'XK8 HARD FAULT Check Sheet' which I have used this evening to diagnose a faulty wheel speed sensor and thanks also to RJ237 for his helpfull resistance values.

As already mentioned, I had the codes read last week and the only one present was a C1175 - 'Rear Left Wheel Speed Sensor Circuit Failure', so rather than flying into the ABS module repair procedure I decided to do some basic resistance / continuity checks on the speed sensors.

Front Left = 1028 ohm
Front Right = 1031 ohm
Rear Right = 1045 ohm
Rear Left = Open Circuit

At this point I was quite pleased, as this at least confirmed the code stored and I was hopeful that it would just be a connection problem. I removed the speed sensor which was quite grubby and put my meter straight accross the terminals and found it was still open circuit. I then also did a continuity test on both sides of the circuit from the multi pin connector down to the two pin sensor connector and found everything was Ok.

I did clean the sensor and poked the two terminals around a bit and eventually I was able to get a reading of 2090 ohms across it, so being curious, I re fitted the sensor and powered up the ignition (after re connecting the ABS connector) and although the check light and ABS lights are still on, I'm no longer getting the Trac / ASC warning and the amber message light has extinguished as well.

So, I'm going to order a new sensor tomorrow and also remove and clean the right hand sensor.

I guess the thing I'm most pleased about is getting the codes read by my local garage. Luckily, the garage owner and I share an interest in old Triumph Heralds (my wife has a convertible called Dolly) and so he was happy to get one of his guys to plug the kit in and read off the codes for nothing.

I'll let you know how I get on once the new sensor is fitted and I've had the code cleared from the ECU.
Andy