How the DPF Pressure
Differential System works

Generally speaking, the pressure differential is measured by a single sensor, rather than 2 seperate pressure sensors (however that configuration is possible. They obtain the pressure by tubes to either side of the filter.

A - Common Cause of
P244b Fault Code

In the above diagram, the tubes marked with A can become clogged with carbon / soot build up. This of course makes the pressure sensor read significantly incorrect, and in turn, the ECU lodge a fault code.

B - Potential Cause of
P244b Fault Code

Second most likely reason for the fault code is that there is a failure of some sort on the electrical side. Usually it’s on the diaphragm part of the sensor as the age and heat take their toll on the part. Usually, if there is a short in the system you’ll get a short circuit fault code along with this one.

C - P244b Caused
From a Full DPF

If you’ve checked both of the above, then it’s time to remove that DPF filter and have it cleaned and checked. IF you bring your filter into a centre, we’ll check the filter over and give you a condition report as to whether the filter can be cleaned or not.