ABS/TCS warning lights

Q: Recently, both the ABS and the TCS warning lights have illuminated on the dashboard of my 2007 Skoda Octavia 1.6 FSI with 99,000 miles. The TCS light could indicate ESP, as both lights are the same design, but I have no idea if the car has a stability programme. Sometimes the light will extinguish and leave the ABS.

My local car mechanic gave the car a thorough testing with the aid of a diagnostic scanner, including two attempts to lock the wheels when braking. During the test, the fault cleared itself and nothing appeared on the print-out. I doubt if the tool was a VCDS and I don’t see why this would make any difference, apart from the labour cost.

At first, the fault was intermittent. Now, the fault is more or less permanent. Without a correct diagnosis, I may end up replacing components at random and getting nowhere. To avoid this, I would like to do some research beforehand and would appreciate your advice. WHA Burgess

A: From the data I have, your Skoda should have a stability programme. As you say, the traction control light and electronic stability control light are identical, but when a fault with one of the systems is detected it should also flag up a warning message in the information display. This will be either ‘Error: traction control (ASR)’ or ‘Error: Electronic Stability Control (ESC)’.

The correct diagnostic equipment is a crucial factor and most good workshops should have the equipment to interrogate the ABS/ESC systems. A road-test involving attempting to lock the wheels is not the best method of diagnosis. Unlike engine codes, there is no European directive on the compatibility of systems to allow codes to be read from the ABS/ESC systems. The correct software will certainly point you in the right direction and it may be a better option to find another garage with the right equipment.