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Home >> Mazda >> 2017 >> CX-9 Signature >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> On-Board Diagnostic - Engine Control System (1 Of 5) >> DTC P0117-00; ECT Sensor No. 1 Circuit Low Input >> Notes
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DTC P0117-00; ECT Sensor No. 1 Circuit Low Input: Notes

DETECTION CONDITION AND POSSIBLE CAUSE

DTC P0117:00 ECT sensor No. 1 circuit low input
DETECTION CONDITION
  • The PCM monitors the ECT sensor No. 1 signal. If the PCM detects that the ECT sensor No. 1 voltage at the PCM terminal 1BI is below 0.2 V for 5 s, the PCM determines that the ECT sensor No. 1 circuit has a malfunction.

    Diagnostic support note

  • This is a continuous monitor (engine cooling system).
  • The check engine light illuminates if the PCM detects the above malfunction condition during the first drive cycle.
  • FREEZE FRAME DATA/Snapshot data is available.
  • DTC is stored in the PCM memory.
FAIL-SAFE FUNCTION
  • Fixes the water temperature for the engine control at 40 °C {104 °F}, and for the idle air control at 80 °C {176 °F}.
  • Operates the cooling fan (high speed rotation).
  • Inhibits the fuel cut control during shift change.
POSSIBLE CAUSE
  • Engine overheating (cooling system malfunction)
  • ECT sensor No. 1 connector or terminals malfunction
  • ECT sensor No. 1 malfunction
  • Short to ground in wiring harness between ECT sensor No. 1 terminal A and PCM terminal 1BI
  • PCM connector or terminals malfunction
  • ECT sensor No. 1 signal circuit and ground circuit are shorted to each other
  • PCM malfunction
G11433209
CAUTION:
  • Verify the malfunction symptom according to not only the PID value but also the symptom troubleshooting.

Related PIDs

Item (definition) Unit/Condition Definition Condition/Specification (Reference)
ECT °C, °F Engine coolant temperature input from ECT sensor No. 1
  • Displays ECT
V ECT sensor No. 1 voltage Ignition switched ON (engine off)
  • ECT is 29 °C {84 °F}: Approx. 2.65 V

    Idle (after warm up)

  • ECT is 88 °C {190 °F}: Approx. 0.71 V