Parts for your 2008 Holden Commodore-Temperature sensors

2008 Holden Commodore temperature sensors — purpose, servicing and replacement

Based on the Holden VE Commodore Workshop Manual and GM Global Service Information (SI), plus common aftermarket guides such as the Gregory’s VE Commodore manual, the 2008 Holden Commodore definitely uses temperature sensors. Key units include the engine coolant temperature (ECT) sensor feeding the engine control module, the intake air temperature (IAT) sensor (integrated with the MAF on many V6 models and separate on some V8s), an ambient air temperature sensor for the HVAC/cluster, and a transmission fluid temperature sensor built into the automatic transmission’s internal harness. They’re not just relevant — they’re essential to how the car runs, cools itself, and reports temperature to the dash.

On the 2008 Commodore, the ECT sensor is the hero. It tells the ECM how hot the engine really is so it can sort cold-start enrichment, ignition timing, idle speed, and when to kick the radiator fans on. The IAT sensor trims fuelling and spark for the actual air temperature coming into the intake. The ambient sensor lets the climate control behave properly and updates the outside temperature readout. The transmission temperature input shapes shift timing and line pressure to protect the gearbox and keep shifts smooth when it’s hot or during towing.

There’s no fixed replacement interval for these sensors — they’re serviced on condition. During routine servicing, a good workshop will scan the live data and look for odd readings (for example, stone-cold engine reporting 80°C, or stuck values), check for DTCs like P0115–P0119, and inspect connectors for corrosion, broken locks, or coolant wicking. If the ECT is faulty, common symptoms include hard cold starts, rich running and poor fuel economy, cooling fans on all the time, an erratic or dead temp gauge, or a check engine light.

• Replacement tips for the ECT: only work on a cold engine, slowly relieve cooling system pressure, catch and dispose of coolant properly, swap the sensor with a new seal/O-ring, refill with the correct long-life red coolant to the logbook spec, bleed the system, then verify live temps and clear DTCs. Tighten to manufacturer spec — don’t overtighten.
• Maintenance tips: keep connectors clean and clipped, fix any coolant leaks promptly, and change coolant at the interval in the service schedule so the sensor and thermostat aren’t sitting in contaminated fluid.
• Parts advice: stick with genuine or OE-equivalent sensors that meet Holden/GM specifications, cheap no-name pieces often read inaccurately and cause more dramas.

Popular questions

Where is the coolant temperature sensor on a 2008 Commodore?
On most VE V6s, it’s typically mounted in or near the thermostat housing/water outlet at the front of the engine. On V8 LS variants, expect it near a coolant passage by the water pump or front of the intake area. Remove the engine cover for a clear look, you’ll see a two-pin connector going to a small threaded sensor in the coolant stream.

Do temperature sensors need regular replacement?
Not usually. They’re replaced on condition. Include a quick live-data check during routine services, follow the logbook coolant change, and inspect plugs and wiring. If readings are implausible, codes are stored, or symptoms line up, that’s the time to replace.

Is it safe to drive with a failed coolant temperature sensor?
It may run in a limp strategy (rich mixture, fans forced on) to protect the engine, but fuel economy and drivability suffer, and overheating risk rises if there are other cooling issues. Best bet is to sort it promptly rather than keep driving.