Parts for your 2018 Mitsubishi Outlander-Temperature sensors

2018 Mitsubishi Outlander temperature-sensors — what they do and when to service them

Drawing on Mitsubishi Motors workshop manuals for the 2018 Outlander (engine electrical, CVT, HVAC/ETACS) and standard OBD‑II fault code documentation, temperature sensors are absolutely fitted to this model and are critical to how it runs. They include the engine coolant temperature (ECT) sensor, intake air temperature (IAT) sensor, transmission fluid temperature sensor for the CVT, ambient air temperature for the climate control, and HVAC evaporator/in‑car sensors. Outlander PHEV variants add battery and power electronics temperature sensing.

These sensors constantly feed data to the engine ECU, transmission control, and HVAC systems. The ECT and IAT sensors help the ECU set fueling and ignition timing, manage cold starts, and control the radiator fans. The CVT fluid temperature sensor protects the transmission by adjusting shift strategy and torque when it’s hot. Ambient and evaporator sensors keep the cabin comfy and prevent evaporator icing. On the PHEV, battery temperature sensors safeguard the lithium‑ion pack and govern charging and power delivery.

• Better drivability: correct cold‑start enrichment and stable idle.
• Cooling control: fans switch on when they should, avoiding overheating.
• Transmission longevity: CVT avoids thermal stress and limp modes.
• Comfort and accuracy: cabin temp readings and A/C performance stay on point.

There’s no fixed replacement interval for these sensors, they’re replaced when faulty. Telltales include hard starting, rough running, poor fuel economy, erratic temp gauge or fans running constantly, A/C misbehaviour, or warning lights with codes such as P0115–P0119 (ECT circuit/performance), P0128 (coolant thermostat rationality), P0711 (CVT fluid temp), or P0070/P0071 (ambient temp sensor). A quick scan‑tool check of live data versus actual temperature under the bonnet is the best first step. If readings are off, confirm with a resistance test (NTC thermistors change resistance with temperature).

When replacing an ECT or similar sensor, use the correct OEM‑spec part, fit a new sealing washer/O‑ring if applicable, and torque to spec. After any coolant‑side work, bleed the cooling system to purge air pockets. Keep electrical connectors clean and avoid tugging on the harness. Regular coolant changes and using the specified CVT fluid help sensors read accurately by reducing corrosion and varnish. For PHEV models, battery and inverter temperature sensors are service‑checked via the factory scan procedure and shouldn’t be disturbed unless diagnostics call for it.

Popular questions about 2018 Mitsubishi Outlander temperature-sensors

Where is the engine coolant temperature sensor located?
On most 2.4‑litre petrol Outlanders, the ECT sensor sits on the cylinder head at the coolant outlet/thermostat housing area near the front of the engine. The exact spot can vary by engine code, so checking the engine section of the workshop manual or using a scan tool to trace the harness is the easiest way to confirm. Access is typically from the top with the engine cover off.

Can a faulty temperature sensor make the radiator fan run all the time?
Yes. If the ECT signal reads unrealistically hot or the circuit is open/shorted, the ECU may default to full fan operation to protect the engine. You may also see poor fuel economy or a rich smell on cold starts. Scan for codes like P0117/P0118 and compare live ECT data with actual coolant temperature to verify before replacing parts.

Do Outlander PHEV models have extra temperature sensors?
They do. In addition to the engine and HVAC sensors, the PHEV has multiple battery temperature sensors and monitoring for the drive motors/inverter. These are managed by the battery management unit and are checked through the factory diagnostic procedure. They’re not routine service items unless a specific fault is logged.