OBD-II reference

All 9.533 generic OBD-II codes, explained in detail.

Causes, inspection steps and sources — a comprehensive DIY archive. Created and maintained with love for the detail. Good luck and have fun!

Powertrain generic / SAE

P2456

DPF Differential Pressure Sensor Circuit Intermittent

The DPF differential-pressure sensor delivers an intermittent signal — usually a marginal connector or a chafed wiring section that breaks contact during temperature or vibration.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number4 / 56

Possible causes

  • Connector intermittent high
  • Wiring chafed against bracket medium
  • Harness routed against vibrating component low

Symptoms

  • Check engine light or DPF warning light on
  • Power loss / limp mode
  • Increased fuel consumption
  • Failed forced regeneration attempts

Inspection / repair

  • Difficulty: easy
  • DIY: possible
  • Estimated cost: 50–250 €
  • Estimated time: 0.3–1.2 h
  • Component: dpf differential pressure sensor
  • Component: dpf pressure sensor wiring
  • MIL / check engine light
  • emissions-relevant
  • drive cycle required

Sources

References

How to read OBD-II codes

The first letter names the vehicle system, the second digit distinguishes generic from manufacturer-specific, the remaining digits group fault area and number.

PPowertrain: engine, transmission, emissions
BBody: chassis trim, comfort, interior
CChassis: suspension, brakes, steering
UNetwork: CAN, control modules, communication