Parts for your 2010 Honda Stream-Temperature sensors

2010 Honda Stream temperature-sensors: purpose, servicing and when to replace

Based on the Honda Stream RN6–RN9 Service Manual (covering 2006–2014), Honda’s Electronic Service Manual for the R18A/R20A engines, and Denso/NTK thermistor specifications commonly used by Honda, the 2010 Honda Stream is fitted with multiple temperature-sensors. These include the engine coolant temperature (ECT) sensor, intake air temperature (IAT) sensor, ambient/ outside air thermistor, and an automatic transmission fluid (ATF) temperature sensor on auto models. So temperature-sensors are absolutely relevant on this model and central to how it runs.

On the 2010 Stream, temperature-sensors help the ECU and related control units fine-tune fuelling, ignition timing, idle speed, cooling fan operation, and transmission shift strategy. The ECT sensor sits in a coolant passage (typically in the cylinder head), telling the ECU how warm the engine is so it can enrich mixtures when cold and kick fans in when required. The IAT sensor (in the air duct or integrated with the MAF/MAP setup, depending on variant) lets the ECU correct for hot or cool intake air. The ambient sensor feeds the climate control and, on some trims, the dash display. Auto transmissions use a fluid temp sensor to protect the box and manage shifts.

• ECT: cylinder head coolant passage
• IAT: intake duct/airbox assembly
• Ambient: front bumper/grille area
• ATF temp (auto): inside transmission

There’s no fixed replacement interval in Honda’s schedules, they’re usually replaced when faulty. Clues include hard cold starts, rough idle, fans running constantly, poor fuel economy, a lazy temp gauge, or OBD-II faults such as P0115–P0119 (ECT), P0110–P0114 (IAT), P0128 (thermostat/rationality), and P0711 (ATF temp). If the Stream’s showing these, a scan tool check against live data—and verifying with a contact thermometer—will usually pinpoint the culprit as outlined in Honda’s diagnostic flowcharts.

Good practice during servicing includes keeping the cooling system healthy (Honda Type 2 coolant, correct mix), bleeding air after any cooling work, ensuring connectors are clean and locked, and checking harness routing so it’s not rubbing on the radiator support. Keep the intake sealed so the IAT reads true, and avoid soaking sensors with engine-bay cleaners.

1. Replace an ECT sensor only on a stone-cold engine. Crack the radiator cap to release any residual pressure, drain a litre or two of coolant.
2. Unplug the connector, remove the sensor, fit a new seal, and torque to the Honda spec (around 18 N·m, confirm in the RN6–RN9 manual).
3. Refill coolant, bleed air, and check for leaks. Clear codes and confirm temps with a scan tool on a test drive.

Quality parts matter—OE Honda or reputable brands like Denso/NTK tend to match the calibration curves Honda’s ECU expects, keeping the Stream running sweet as.

FAQs

How many temperature-sensors does a 2010 Honda Stream have and where are they?
The common ones are the ECT (in the head’s coolant passage), IAT (in the intake duct), an ambient/outside air thermistor (near the front bumper or grille), and an ATF temperature sensor on auto models. Some trims may also use additional thermistors for the A/C evaporator and cabin air mix for climate control.

What are typical symptoms or fault codes of a bad temperature-sensor on a Stream?
Expect hard cold starts, high idle, rich running, poor fuel economy, or the radiator fans staying on. Codes often seen are P0115–P0119 for ECT faults, P0110–P0114 for IAT, P0128 for thermostat/ECT rationality, and P0711 for ATF temp. The Honda diagnostic steps compare sensor readings to expected values and to actual temps.

Can a DIYer replace the coolant temperature sensor at home?
Yes, with basic tools. Work on a cold engine, catch a bit of coolant, swap the sensor and seal, torque to spec, then refill and bleed the system. A scan tool to confirm live temperature readings after the job is the icing on the cake. If unsure, a trusted mechanic can sort it quickly.