Just had a yellow “engine malfunction” warning up, called it in so had the joys of waiting for Scania assist. No drama. He plugged in the computer and said uts a differential pressure sensor, cleared the fault and said its fine to go home but if activated again I’ll get a limp mode countdown but its way longer than needed to get it back to base.
I even got a snazzy Scania branded breakdown bag which will be on ebay shortly
Question is what does this component do? I’m aware it likely measures pressures within the differential but why could wet it off? Could be a one off thing? Could it be to do with use of diff lock on snowy inclines last week?
It’s not in the differential, that’s in the axle and as far as I know no lorry has sensors in there because it’s not possible to build up pressure in it.
I would have thought it was referring to the pressure sensors in the DPF filter. They measure the pressure of the exhaust gases entering and exiting the DPF filter to calculate how full it is by comparing the differential between the two. My last car had a known issue with the rubber pipes going to the sensors splitting with age and it’d throw up a fault code that was similar.
Conor:
It’s not in the differential, that’s in the axle and as far as I know no lorry has sensors in there because it’s not possible to build up pressure in it.
I would have thought it was referring to the pressure sensors in the DPF filter. They measure the pressure of the exhaust gases entering and exiting the DPF filter to calculate how full it is by comparing the differential between the two. My last car had a known issue with the rubber pipes going to the sensors splitting with age and it’d throw up a fault code that was similar.
I’d agree that there is unlikely to be a pressure sensor in the diff. However pressure build up is possible due to heat, which is why they generally have breathers. Blocked breather (rare) means oil blown through seals onto brakes.
Connor’s right…it’s the pressure before and after the PM filter. If the ‘differential’ (difference in plain English) between the two exceeds a limit, the light comes on as the filter may be clogging up.
but why could wet it off? Could be a one off thing? Could it be to do with use of diff lock on snowy inclines last week?