Parts for your 2012 Honda Stream-Temperature sensors

2012 Honda Stream temperature-sensors: what they do and how to look after them

According to Honda technical documentation for the Stream RN6–RN9 series (2012 Service Manual, Engine/ECM chapters) and the Honda parts catalogue, the 2012 Honda Stream is fitted with multiple temperature-sensors. These include an Engine Coolant Temperature (ECT) sensor, an Intake Air Temperature (IAT) sensor, an Automatic Transmission Fluid (ATF) temperature sensor on auto models, and an ambient air temperature sensor for the climate control. OBD‑II standards (SAE J1979/ISO 15031) also specify ECT and IAT as core inputs, reinforcing that these sensors are integral on this model.

On this Stream, temperature-sensors help the ECU choose the right fuel and ignition strategies, trigger the radiator fans, manage cold-start enrichment, display the dash temperature, and keep the air‑con behaving on hot Kiwi and Aussie days. The ECT sensor tells the car exactly how warm the engine is, the IAT helps nail air density calculations, the ATF temp sensor protects the transmission by adjusting shift logic when the fluid gets hot, and the ambient sensor keeps cabin temp control on point.

There’s no fixed replacement interval for these sensors, but they do age. Corrosion, heat cycling and wiring fatigue are the usual culprits. A crook ECT or IAT can cause hard cold starts, hunting idle, lazy fan operation, rich running, ordinary fuel economy, or a check‑engine light with codes like P0115–P0119 or P0110–P0114.

• Quick checks: With a scan tool, compare cold ECT to ambient before first start, they should match. Watch ECT rise smoothly as the engine warms. IAT should track changes as intake air temp shifts.
• Replacement tips: Always work on a cold engine. For the ECT sensor (mounted on the cylinder head/thermostat housing on R18A/R20A engines), relieve cooling system pressure, drain a little coolant, swap the sensor and sealing washer, then refill with Honda Type 2 blue coolant. Bleed air properly and verify fan operation. For the IAT (integrated with the intake duct/MAP assembly on many trims), ensure the connector and loom aren’t brittle and the sensor element is clean. Avoid overtightening, use the torque spec in the Honda manual.
• Good practice: Stick to quality OEM‑equivalent sensors, repair any greened‑up terminals, and secure the loom away from hot exhaust components. After any sensor change, clear codes and road‑test while watching live data.

Looked after, the Stream’s temperature-sensors quietly keep the engine and cabin happy across thousands of kilometres. When they act up, a bit of smart diagnosis and the right parts get it back to running sweet as.

Popular questions about 2012 Honda Stream temperature-sensors

Where is the engine coolant temperature sensor on a 2012 Honda Stream?

On the R18A and R20A engines used in the 2012 Stream, the ECT sensor sits on the cylinder head near the thermostat housing, typically below the intake ducting. It’s reachable from the top once the intake snorkel is out of the way. Expect a two‑pin connector and a small sealing washer under the sensor.

Does the 2012 Stream have more than one temperature sensor?

Yes. Along with the ECT sensor, there’s an IAT sensor for engine management, an ambient air temperature sensor for the HVAC system, and an ATF temperature sensor on automatic models. The dash gauge is driven by the ECU using the ECT reading rather than a separate sender.

Can a faulty temp sensor cause rough cold starts or high fan speed?

It can. If the ECT reports the wrong temperature, the ECU may over‑fuel or under‑fuel during warm‑up and command the radiator fans at odd times. The fix is to confirm with a scan tool, check wiring, and replace the sensor if readings are implausible or jumpy.