sprie

I have the ABS and Diff Control warnings each time i start the car, which i need to fix before i get an MOT.
I have done lots of work on the car and now have a rebuilt PSD and replacement sensors - so there WAS clearly errors to be reported. But i don't know whether the current warnings are hangovers (which need clearing) or whether i still have issue (s) to be fixed.

Does anyone know whether these warnings have to be cleared with a diagnostic tool (e.g. Hammer) or whether they clear themselves if you unplug the battery (I do leave the earth battery lead disconnected each night). I have also seen someone mention 50 ignition cycles as a way of clearing errors.

khalloudy

Unplugging the battery won’t be of use. You need to fix the fault.

SeanR

Nope, you need to diagnose the issue. Starting the car and no fault is a good and easy thing. Rolling forward and the fault triggers after moving means you have a speed sensor issue. Check the 4 wheels and have some fun. The easiest way is the 2 LED Bosch tester. Not many of those around.

mj1pate

At the basic level, check the wheel to wheel circuit cable for chaffing. The cable running over the rear half shafts tends to drop down from its mount points with rot and time and potentially get beat up by the rotating half shafts.