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

P2500

Generator Lamp/L-Terminal Circuit Low

The L-terminal feedback line from the alternator (charging warning lamp circuit) reads below the lower limit. The lamp may stay on, and battery voltage may drift if regulation feedback is also affected.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number5 / 00

Possible causes

  • L-terminal shorted to ground high
  • Alternator regulator failed medium
  • Connector pins corroded - high contact resistance low

Inspection / repair

  • Difficulty: medium
  • DIY: possible
  • Estimated cost: 80–800 €
  • Estimated time: 0.5–3 h
  • Component: alternator
  • Component: charging warning lamp wiring
  • MIL / check engine light

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