EPSSensor

Exhaust Pressure Sensor (DPF Differential Pressure) (EPS)

Group: Emissions and exhaust

The exhaust pressure sensor measures the pressure difference before and after the diesel particulate filter (DPF). The computer uses it to work out how much soot the filter has collected and when to regenerate it.

Contents

What does the EPS sensor do?

As the DPF fills with soot, the pressure difference between its inlet and outlet increases. When it passes a threshold, the computer starts a regeneration: it raises exhaust temperature to burn off the soot. If the pressure is too high and the regeneration does not complete, the DPF warning light comes on and the engine may go into limp mode.

Where is it located?

In the engine bay or on the body, with two pipes or hoses connected to the inlet and outlet of the DPF.

Signal type and reference values

  • 3 wires: 5 V, ground and signal.
  • Engine off: differential pressure close to 0 (about 0.5 to 1 V).
  • At idle with a clean DPF: a few millibar; it rises in proportion under heavy load.

Values are a guide only: always check the manufacturer's data for your engine.

Symptoms of a bad EPS sensor

  • DPF warning light on.
  • Very frequent regenerations, or regenerations that never finish.
  • Loss of power and limp mode.
  • Codes P2452 to P2455, P2002 and P2463.

How to test the EPS sensor step by step

  1. Check the sensor pipes and hoses: a loose or blocked hose gives false readings.
  2. Engine off, ignition on: differential pressure should be close to 0.
  3. At idle and at 2,500 RPM, compare the reading with the manufacturer's values for a clean filter.
  4. If the sensor reads correctly and the pressure is high, the filter really is clogged: forced regeneration with a scan tool, or cleaning.

Trouble codes related to the EPS sensor

Frequently asked questions about the EPS sensor

Can a bad DPF pressure sensor clog the filter?
Yes, indirectly: if it reads less pressure than there really is, the computer does not start the regeneration and the filter fills up.
What is a forced regeneration?
A regeneration started with a scan tool at the shop, when the filter could not clean itself during normal driving.

Updated September 25, 2026. Values are a guide only: always confirm them in the service manual for your engine.

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