Parts for your 2001 Toyota Caldina-Temperature sensors

2001 Toyota Caldina temperature sensors

Temperature sensors are absolutely used on the 2001 Toyota Caldina. Toyota technical sources back this up: the Toyota Electrical Wiring Diagram (EWD) for Caldina ST215/AT211 (late 1990s–2002) shows the Engine Coolant Temperature (ECT) sensor feeding the ECM (THW/E2). Toyota New Car Features (NCF) and engine repair manuals for the 3S‑GTE, 1ZZ‑FE and 1AZ‑FSE detail coolant and intake air temperature inputs, and the Toyota EPC lists an ECT sensor for 2001 Caldina models (commonly p/n 89422‑20010), with the intake air temperature often integrated in the MAF on 1ZZ‑FE (e.g., 22204‑22010). Those same manuals note OBD‑II diagnostics like P0115–P0119 for ECT circuits used on these cars.

On a 2001 Caldina, temperature sensors help the engine computer decide fuelling, ignition timing, idle speed and cooling fan operation. They also influence transmission shift strategy and air‑con performance. In short, they keep the wagon running sweet whether it’s a frosty morning in Dunedin or a hot arvo in Darwin.

• Engine Coolant Temperature (ECT): usually on the thermostat housing/coolant outlet, critical for cold start enrichment, fan control and overall engine mapping.
• Intake Air Temperature (IAT): on many engines it’s built into the MAF, affects mixture and knock control.
• Ambient/evaporator temp (HVAC): helps climate control behave itself.

They’re not a routine “replace-by-date” item, but they do appreciate a bit of attention during servicing.

1. Scan check: with a scan tool, ECT should read close to ambient when cold and climb smoothly to roughly 80–95°C at operating temp. Any wild spikes or stuck readings are a red flag.
2. Visuals: inspect connectors for green crusties, broken tabs or oil/coolant wicking into the loom. Fix poor grounds and damaged plugs.
3. Cooling system health: old coolant, air pockets and sticky thermostats can make a good sensor look bad. Keep coolant fresh (Toyota Red/long‑life, don’t mix colours) and bleed the system properly.
4. Replacement: only when faulty. Let the engine go stone cold, relieve pressure, unplug, spin the sensor out, swap the seal/O‑ring, and refit. Typical torque is around 20 N·m—always check the Toyota manual for your engine code.

Common signs a sensor is on the way out include hard cold starts, rich running and soot, lazy or roaring radiator fans, rough idle and a check engine light (think P0115–P0119 for ECT). A fresh, quality sensor and tidy wiring will save fuel and keep the Caldina feeling perky.

FAQs

Where’s the coolant temperature sensor on a 2001 Caldina?
It’s typically threaded into the coolant outlet/thermostat housing on the cylinder head. On 1ZZ‑FE it’s on the water neck at the head, on 3S‑series engines it’s near the coolant neck by the timing side. Look for a two‑pin connector.

How can they tell if the ECT sensor is dodgy?
Use a scan tool from dead‑cold: ECT should match outside temp and then rise smoothly. Erratic jumps, a stuck low (~−40°C) or stuck high (~130°C) reading, rich fuel use and DTCs like P0115–P0119 point to trouble. An ohms check off‑car should roughly show a few kΩ at 20°C and a few hundred Ω near 80–90°C.

Should the intake air temp sensor be serviced too?
Yes. If it’s integrated with the MAF, clean the MAF carefully with proper MAF cleaner—don’t touch the element. A filthy MAF/IAT can cause hesitation and poor economy. If it’s a separate IAT, check its plug and housing for damage.