Exhaust Back Pressure Sensor – Mercedes OM642 Engine – A0091535028

This direct-fit exhaust back pressure sensor (DPF differential sensor / DPF pressure sensor) restores reliable DPF regeneration and turbo boost control on the Mercedes-Benz Om642. Built to OEM specification and matching part numbers 68013186AA, 68013186AB, 0061531128, 0041539828 and A0091535028.

Common signs of failure

A failing exhaust back pressure sensor on diesel vehicles typically triggers fault codes P0470, P0471, P0472 or P2452 (DPF differential pressure circuit), plus DPF warning lights on the dashboard. Symptoms include incomplete or failed DPF regeneration cycles, excessive black smoke under acceleration, the vehicle entering limp mode after motorway driving, and reduced turbo boost. Left unaddressed, a faulty sensor can cause the DPF to block.

Fitment notes

Direct-fit replacement, mounted to the chassis or bulkhead with two small-diameter pipes feeding to either side of the DPF. Check the pipes for blockage or splits during the swap — blocked pipes produce the same symptoms as a faulty sensor. No diagnostic coding required after fitting. Standard 3 pin connector.

Frequently asked questions

How does this sensor work?

It measures the pressure difference between the inlet and outlet of the DPF — telling the ECU how blocked the filter is and when to trigger a regeneration. A faulty sensor either over- or under-reports DPF loading.

Can blocked pipes mimic a sensor fault?

Yes, very commonly. Soot and condensation block the small pressure pipes that connect to the sensor, producing identical fault codes. Always inspect and clean the pipes when fitting a new sensor.

Will it fix my limp-mode fault?

If limp mode was triggered by P0470-series DPF pressure codes, replacement (plus a forced regen on diagnostic equipment) should clear the fault.