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

P2A37

AFCM Power Relay Sense Circuit High

The sense feedback voltage from the AFCM power relay is above the expected window. Indicates relay output is energised when the relay should be off, or wire shorted to B+.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / numberA / 37

Possible causes

  • Relay contact stuck closed high
  • Feedback wire shorted to B+ medium
  • Connector pins corroded - high contact resistance low

Inspection / repair

  • Difficulty: medium
  • DIY: shop recommended
  • Estimated cost: 120–600 €
  • Estimated time: 0.5–3 h
  • Component: afcm power relay
  • Component: afcm
  • Component: wiring harness
  • MIL / check engine light
  • emissions-relevant
  • limp mode possible

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