P0117 OBD II Trouble Code Engine Coolant Temperature (ECT) Circuit Low Input

Detailed information on troubleshooting and repairing a p0117 vehicle trouble code which refers to a low input in the engine coolant temperature (ECT) circuit. Also includes links to relevant forum topics on the code.

Symptoms of P0117 OBD II Trouble Code

  • MIL (Malfunction Indicator Lamp) illumination
  • Poor fuel economy
  • Poor drivability
  • Engine may run rough or blow black smoke out the tailpipe
  • May not idle
  • May start and then die

Common Causes of P0117 OBD II Trouble Code

  • Bad ECT sensor
  • Short to ground on ECT signal circuit
  • Faulty or damaged connectors
  • Wiring harness damaged
  • Loose terminals at ECT or PCM
  • POSSIBLY an overheated engine
  • Bad PCM