Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

2006 Mazda MPV ESFACTORY OEM SERVICE PROCEDURE

DTC P0118: Notes

DTC P0118 [AJ] DETECTION CONDITION AND POSSIBLE CAUSES

DTC P0118

ECT circuit high input

DETECTION CONDITION

The PCM monitors ECT sensor signal at PCM terminal 41. If the PCM detected ECT sensor voltage above 4.58 V , the PCM determines that the ECT sensor circuit has malfunction.

Diagnostic support note

This is a continuous monitor (Engine cooling system).
The MIL illuminates if the PCM detects the above malfunction condition in the first drive cycle.
PENDING CODE is available if the PCM detects the above malfunction condition.
FREEZE FRAME DATA is available.
DTC is stored in the PCM memory.

POSSIBLE CAUSE

ECT sensor malfunction
Connector or terminal malfunction
Open circuit between ECT sensor terminal A and PCM terminal 41
Short to power circuit between ECT sensor terminal A and PCM terminal 41
Open circuit between ECT sensor terminal B and PCM terminal 20
PCM malfunction

Courtesy of MAZDA MOTORS CORP.

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.