Whenever a driver gets an ABS Warning Light the first thing that is thought is that the fault is with the trailer. But is it really?
The driver will then state that when he connects to other trailers the ABS warning light doesn’t come on, so it must be the trailer!
So how do we quickly determine if a fault is with the truck or the trailer?
ISOCheck is a test lead that will quickly and simply identify if all the electrical power information is being outputted from the truck correctly, if so a bright Green LED Ring will light, if not a Red LED Ring will light, then testing the trailer and truck together the information sent from the trailer is checked.
This product will save time in calling out the correct truck or trailer repairer to warning light activations and is ideal to check the ISO socket on inspection intervals.
Hours could be spent looking at the trailer or truck, a simple test of the ISO socket would save so much time.
Trailer hire companies often have the problem of customers picking up trailers and once the truck has been connected the Warning Light has been activated, the driver will straight away blame the trailer as having a fault.
Hours may have been spent preparing the trailer and then a question will occur is it the trailer or the tractor unit?
With ISOCheck the discussion will be short and the fault will be identified as the truck or the trailer!
Furthermore below is a recent case study of a rare warning light problem.
This case study highlighted a potential problem that all commercial truck and trailer operators could meet.
This particular problem relates to a truck having a LCD or dot matrix electronic dash and the power to Pin 5 in the ISO Socket is being fed from the dash. This is OK if the trailer has an Electronic Braking System fitted but if the trailer has certain makes of ABS then the trailers ECU needs to see 24 volts at pin 5 but the truck in some cases will be only sending 5 volts or less to pin 5.
So why is this causing a warning light fault?
Certain older types of ABS will ground pin 5 when it sees 24 volts coming down pin 5 (the warning light wire), turning the warning light on in the truck. Most ECU’s will do a static self test of all connected components and if all is OK the ABS systems ECU will remove the ground to pin 5, which turns the warning light off in the truck.
So this sounds OK but if the truck has an LCD dash and the warning light is basically an LED, then there is not enough load on pin 5 to draw it down to ground and the light stays on.
Older trucks have a 5 watt bulb for the warning light and the bulb is what makes the system work correctly.
A good example of this was reported by a commercial repairer recently, while working on a Renault Magnum with a Haldex Modal ABS trailer, no faults were reported on the trailer but the warning light on the truck would not turn off even after it had been driven. The only way to cure the fault was to put a 5 watt load on pin 5 on the trailer, so this will make the trucks dash work correctly.
You can read further at ISOCheck.
