DTC P0117; Pcm ECT Sensor No. 1 Circuit Low Input: Notes
WARNING: This page is about a different car, the 2017 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.
DETECTION CONDITION & 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 1AK 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 (Mode 2)/Snapshot data is available.
- DTC is stored in the PCM memory.
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| 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.
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| 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 1AK
- PCM connector or terminals malfunction
- ECT sensor No. 1 signal circuit and ground circuit are shorted to each other
- PCM malfunction
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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 |
|
| V |
ECT sensor No. 1 voltage |
- ECT is 20 °C {68 °F}: Approx. 3.10 V
- ECT is 40 °C {104 °F}: Approx. 2.16 V
- ECT is 60 °C {140 °F}: Approx. 1.40 V
- ECT is 80 °C {176 °F}: Approx. 0.87 V
- ECT is 100 °C {212 °F}: Approx. 0.54 V
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