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.

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HOMESERVICE MANUALSMAZDA20086 S SPORT, 4D HATCHBACK, STANDARDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 589 (ON-BOARD DIAGNOSTIC [ENGINE CONTROL SYSTEM L3 WITH TC])DTC P0118NOTES

2008 Mazda 6 s Sport, 4D Hatchback, Standard

DTC P0118: Notes

2008 Mazda 6 s Sport, 4D Hatchback, StandardSECTION Notes

WARNING: This page is about a different car, the 2007 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

DTC P0118 DETECTION CONDITION AND POSSIBLE CAUSES

DTC P0118

ECT sensor circuit high input

DETECTION CONDITION

The PCM monitors the ECT sensor signal. If the PCM detects the ECT sensor voltage is above 4.6 V , the PCM determines that the ECT sensor circuit has a malfunction.

Diagnostic support note

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

POSSIBLE CAUSE

ECT sensor malfunction
Connect or terminal malfunction
Open circuit in the wiring harness between ECT sensor terminal A and PCM terminal 1M
Short to power supply in the wiring harness between ECT sensor terminal A and PCM terminal 1M
Open circuit in the wiring harness between ECT sensor terminal B and PCM terminal 2H
PCM malfunction

Courtesy of MAZDA MOTORS CORP.

RENDER: 1.0x

NO RELATED

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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.