Not having ABS rings on my CVS, for several years I've benefited from a method of MOT testing where the car doesn't leave the tester's garage and so the ABS warning light does not come on. However, if the car is fully road tested then it becomes apparent that the ABS doesn't work because the warning light comes on after about 200-300m of driving. This is regarded as a fail. Historically, I have fixed it so the light does not come on, but that prevents the diff locks coming on because it seems the light is in the circuit, so I had to reverse that change out.
does anyone know of another way to 'fix' this without stripping down and fitting the rings ?
The ABS is disabled for a couple of reasons, first it cannot work effectively when the centre differential is engaged locking the two axles together, and secondly ABS is not desirable when off road.
Here in Spain they are all over the dashboard at the ITV (MOT) stations, they want to see the lot ABS/Air Bag/OBD/EPS and so forth. Occasionally I get a vehicle with an OBD light appearing after fixing the apparent fault only for it to return as you pull into the station. Of course if you have forgotten your Bluetooth dongle, not a problem, I tell the tester and one of them will lend me their one.
A little insight, if you change a track rod end on many modern cars the EPS/ABS will come on after a couple of KM's (on the way to get it tracked) as it detected the tracking is out of spec, adjust the tracking and it goes back out after driving it around the block! Particularly fussy are Mercedes 4 x 4's
Something I find odd here is many of the testers here are pretty much straight out of school and might not even own a car. They go to ITV 'school' and study to be a tester perhaps never having held a spanner in their hand, in the UK it was IIRC was always a mechanic who REALLY knew what he was looking for. I have a really
great story about a cocky young ITV inspector who messed with me when I presented a car for testing but will keep that for another day.
Of course you can fit timers and so forth on our older cars but more more modern vehicles the dashboards are all LED's soldered in and interfering with them upsets the BCM or body control module.
One customer had a fault where her oil light did not light with the ignition on but engine off, a new BCM was around £500.00! With her permission I disconnected the switch from the oil pressure sensor and drilled a tiny hole in the bottom of her dashboard binnacle and fed in a 12v flashing red LED, with it fed 12v from the ignition and the earth supplying the return circuit (which is not entirely true because it is the other way around in electrical reality) the light flashes and goes out when the engine is started. The LED is small and discreet in the lower part of the dashboard but is very bright and noticeable when the ignition is switched on, total cost about £20.00 parts and labour.
If the inspector knows his job he is supposed to check to see if the vehicle he is testing was fitted with ABS and then look for the telltale light, which we know can be avoided, as AFAIK all new vehicles have it as standard so it will only be the older cars that need to be looked up.
My dashboard is presently out and in the workshop as I am still trying to get a speedometer for it however, IIRC there is a bulb, I will check for you later this morning.