Parts for your 2003 Honda Cr-v-Temperature sensors

2003 Honda CR‑V Temperature Sensors — What They Do and How to Look After Them

Temperature sensors are absolutely fitted to the 2003 Honda CR‑V and they’re central to how the vehicle runs. Honda’s 2002–2004 CR‑V Service Manual, Honda parts catalogues, and workshop databases used by technicians confirm several temperature inputs on the K24‑series engine: an Engine Coolant Temperature (ECT) sensor on the thermostat housing, an Intake Air Temperature (IAT) sensor in the intake tract, an ambient air temperature sensor for the air‑conditioning, and on automatic models an internal automatic transmission fluid (ATF) temperature sensor. They’re not optional—these sensors feed the ECU/PCM critical data for reliable starting, smooth drivability, and fan control.

On this model, the ECT sensor helps the ECU decide how much fuel to add on cold starts, when to kick the radiator fans in, and how to protect the engine if temps spike. The IAT sensor trims fuelling and ignition as the intake air warms up or cools down, improving economy and throttle response across Aussie and Kiwi weather swings. Ambient temp input helps A/C performance, while the ATF temp sensor (auto only) influences shift quality and transmission protection.

There’s no fixed replacement interval for these solid‑state sensors, but they do age. Common signs they’re crook include hard cold starts, rich running, lousy fuel economy, cooling fans stuck on or never coming on, a wonky temp gauge, or fault codes like P0117/P0118/P0128 (ECT) and P0112/P0113 (IAT).

• Quick checks: Inspect connectors for corrosion, broken locks, and oil/coolant wicking into plugs. With a scan tool, compare ECT and IAT readings to outside temperature after an overnight cold soak—they should be close.
• ECT sensor replacement tips: Work on a cool engine. Drain a little coolant, unplug the sensor, crack it out, and fit the new unit with the correct sealing washer or O‑ring. Refill with Honda Type 2 blue coolant, bleed the system, and verify both fans cycle properly.
• IAT care: If it’s separate from the MAF, remove it gently and clean the element with a sensor‑safe spray—don’t touch the tip. Replace the O‑ring if it’s flattened or split.

Stick with quality OEM‑equivalent parts. A tidy sensor and a clean, tight connector can save litres of fuel over thousands of kilometres, keep the temp needle where it should be, and stop the CR‑V from throwing tantrums on hot summer runs.

Popular questions about 2003 Honda CR‑V temperature sensors

How many temperature sensors does a 2003 CR‑V have and where are they?

The 2003 CR‑V typically has an Engine Coolant Temperature sensor on the thermostat housing and an Intake Air Temperature sensor in the air intake tract or airbox. Most models also include an ambient air temperature sensor for the A/C near the front grille. Automatic transmissions add an internal ATF temperature sensor. Exact locations can vary slightly by market and trim.

Do these sensors need regular replacement?

There’s no scheduled interval. Replace only if readings are implausible, wiring is damaged, or fault codes/logs indicate failure. During servicing, it’s smart to scan live data, check connectors, and ensure the cooling fans operate as expected. Use Honda Type 2 coolant after any ECT work and bleed the system properly.

What are the symptoms of a failing ECT or IAT sensor?

Hard cold starts, rough idle when warm, poor fuel economy, black exhaust soot, erratic fan behaviour, an over‑ or under‑reading temp gauge, and DTCs such as P0117, P0118, P0128 (ECT) or P0112, P0113 (IAT). If the CR‑V runs rich or the fans act oddly, check these first.