How to diagnose a problem the DPF Differential Pressure sensor and its impact on the DPF. known in mes parameter list as Differential Pressure Sensor.
These sensors are prone to any debris or condensation in the exhaust, which can cause the sensor pipes to become blocked / partially blocked with water. thus causing the sensor to fail completely.
The problem you can get with continuing to drive for any real distance with this situation is that, as the sensor is now ineffective the engine will not perform any regeneration and so the dpf will become blocked.
Example sensors used on Ducatos
Differential Pressure Sensor signal is measured in mV.
an example of Pressure versus mV
What is an acceptable figure for DPF Differential Pressure (measured in mbar)? The answer is as little as possible. But if it flatlines at zero its dead.
Adding back pressure will make the engine work harder, and use more fuel to deliver the same power.
<20 Brilliant DPF causing almost no restriction
20-99 Good result and typical of a DPF in good working order
100-250 DPF causing up to 0.25 BAR of pressure – needs investigation
250-500 Serious restriction probably not allowing car to do a Forced Regen
500-1000 Performance loss very marked at this level
>1000 Car can’t pull the proverbial skin off a rice pudding. All your boost is stuck in the DPF
Some example graphs
Test 3 DPF clogged was trying to regen every 70miles
Test 1 regen very 314 miles
Note if you change the sensor it will require reprogramming to the ecu, this is done in MES section F7 Adjustments Differential pressure sensor replacement.
These sensors are prone to any debris or condensation in the exhaust, which can cause the sensor pipes to become blocked / partially blocked with water. thus causing the sensor to fail completely.
The problem you can get with continuing to drive for any real distance with this situation is that, as the sensor is now ineffective the engine will not perform any regeneration and so the dpf will become blocked.
Differential Pressure Sensor signal is measured in mV.
an example of Pressure versus mV
What is an acceptable figure for DPF Differential Pressure (measured in mbar)? The answer is as little as possible. But if it flatlines at zero its dead.
Adding back pressure will make the engine work harder, and use more fuel to deliver the same power.
<20 Brilliant DPF causing almost no restriction
20-99 Good result and typical of a DPF in good working order
100-250 DPF causing up to 0.25 BAR of pressure – needs investigation
250-500 Serious restriction probably not allowing car to do a Forced Regen
500-1000 Performance loss very marked at this level
>1000 Car can’t pull the proverbial skin off a rice pudding. All your boost is stuck in the DPF
Some example graphs
Test 3 DPF clogged was trying to regen every 70miles
Test 1 regen very 314 miles
Note if you change the sensor it will require reprogramming to the ecu, this is done in MES section F7 Adjustments Differential pressure sensor replacement.
