Parts for your 2001 Honda Accord-Temperature sensors

2001 Honda Accord temperature sensors — what they do and how to look after them

Temperature sensors are absolutely fitted to the 2001 Honda Accord and are central to how it runs and keeps its cool. Honda’s 1998–2002 Accord Factory Service Manual (Helm), the 2001 Accord Electrical Troubleshooting Manual, and trade databases such as AlldataDIY and Mitchell ProDemand all document the Engine Coolant Temperature (ECT) sensor and Intake Air Temperature (IAT) sensor, with automatic models adding a transmission fluid temperature sensor. Variants with automatic climate control also use ambient and in-car temperature sensors for HVAC behaviour.

The ECT sensor tells the powertrain control module how hot the engine is, shaping cold-start fuelling, ignition timing, idle speed and radiator fan operation. On some variants there’s a separate one-wire sender just for the dash gauge. The IAT sensor measures the temperature of the air entering the engine so the ECU can fine-tune the air–fuel mix. Automatic models monitor transmission fluid temperature to manage shift timing and protect the gearbox, while climate control sensors help the cabin reach and hold the set temperature.

Because these are solid-state parts, there’s no scheduled replacement. Still, they deserve a quick check during routine servicing:

• Scan for fault codes and live data (e.g., ECT/IAT readings vs ambient). Codes like P0115–P0119 (ECT), P0113 (IAT) or P0128 (thermostat) flag issues.
• Inspect connectors for green crust, broken tabs or oil/coolant wicking. Clean and reseat as needed.
• Keep the cooling system healthy with the correct Honda Type 2 coolant and proper bleeding to avoid air pockets that can fool the ECT.

Common symptoms of a dodgy ECT or IAT include hard cold starts, rough idle, rich running, poor fuel economy, cooling fans not behaving, or the temp gauge reading strangely (where a separate sender is used). A failing transmission temp sensor can cause odd or harsh shifts. If replacement is needed, use quality OEM-equivalent parts, follow the factory torque spec and sealing guidance, and on coolant sensors, drain and bleed the system properly. The IAT is usually a simple plug-and-play swap on the airbox or intake tube, the ATF temp sensor and some climate sensors are trickier, so many owners leave those to a pro. Look after the basics and these sensors will go the distance, keeping the Accord smooth and efficient across Aussie and Kiwi conditions.

Popular questions

Where is the coolant temperature sensor on a 2001 Accord?
On most 4-cylinder models it’s threaded into the thermostat housing or cylinder head near the upper radiator hose. V6 models typically place it near the thermostat housing/water crossover. Access varies by engine, allow the engine to cool before unplugging or removing any sensor.

Do temperature sensors need regular replacement?
No, there’s no time/km-based interval. Replace only if testing shows it’s out of range or if faults are logged. If the Accord has hard cold starts, poor economy, cooling fans misbehaving or a P0115–P0119/P0128 code, check sensor data before condemning the part.

Can a bad temperature sensor affect fuel economy or shifting?
Yes. An ECT that reads “cold” can keep the mix rich and idle high, burning more fuel. On automatics, a faulty transmission fluid temp signal can alter shift timing or feel. Sorting the sensor and its wiring often restores normal operation.