P2509 – ECM/PCM Power Input Signal Intermittent

Description

The ECM detects an intermittent loss of power or ground reference.

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Symptoms

  • Stalling
  • No start
  • Intermittent misfires
  • Electrical issues

Causes

  • Loose battery connections
  • Faulty ECM relay
  • Wiring issues
  • Ground faults

Diagnosis

  • Inspect battery terminals
  • Check ECM relay
  • Inspect grounds
  • Test wiring continuity

Repair

  • Tighten battery connections
  • Replace relay
  • Repair wiring
  • Fix ground faults

Related Problems

Related Fault Codes