Parts for your 1999 Mitsubishi Pajero-Temperature sensors

1999 Mitsubishi Pajero temperature sensors – what they do and how to look after them

Temperature sensors are absolutely fitted to the 1999 Mitsubishi Pajero. Mitsubishi’s Factory Service Manual for 1997–2000 Pajero/Montero models (engine management and cooling sections), the Mitsubishi ASA parts catalogue, and mainstream workshop data (e.g., Haynes and Autodata) all show multiple temperature sensors on this vehicle. Depending on engine (3.0/3.5 V6 petrol or 2.8 TD 4M40), the Pajero uses an engine coolant temperature (ECT) sensor for the ECU, a separate sender for the dash gauge on many variants, an intake air temperature (IAT) sensor (integrated with the MAF on V6 petrol), an automatic transmission fluid (ATF) temp sensor on autos, and ambient temp sensors for HVAC.

On this model, the ECT sensor is the star of the show. It tells the ECU how warm the engine is so it can sort cold-start enrichment, ignition timing, idle speed, thermo-fan control, and overheat protection. On the 4M40 diesel, ECT input also guides glow plug after-heating and fast idle. The IAT trims fuelling as the air warms up or cools down, helping drivability and economy. In auto models, the ATF temp sensor helps the transmission computer pick the right shift strategy and lock-up timing.

These sensors aren’t “service items” in the same way as filters, but they should be checked whenever the cooling system is serviced. A quick scan-tool look at live data is gold: when stone-cold, ECT should read close to ambient