GM · DTC LOOKUP

GM VATS resistor mismatchGM ECM rejects key — wrong resistor value or broken wire

GM diagnostic code. Below: what it means, common causes, symptoms, and the exact bench-programming fix path.

Common causes

  • Resistor pellet in key worn after 20-30 years of insertions
  • Resistor wire inside ignition lock cylinder fatigued/broken
  • VATS module under dash failed
  • Aftermarket key cut with wrong resistor value
  • Ignition lock cylinder swap broke resistor contact

Symptoms you'll see

  • Cranks normally, no fuel pulse
  • Security light flashing on dashboard
  • Starts then dies after 1-2 seconds
  • Worked yesterday, doesn't today (wire fatigue scenario)

The fix path

Dealer-equivalent fix is ignition lock cylinder replacement + new keyed pellet ($300-500). Community-standard fix is GM VATS Delete ($150) at the ECM level — removes the check entirely so any compatible mechanical key starts the car. Works on all VATS-era ECMs (1227165, 1227727, 1227730, 16139379 etc.).

AML services that fix this

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