P2609
Intake Air Heater System Performance
- Severity
- Low
- Driving
- Drivable — book it in
The intake air heater system as a whole is not performing as expected. The module heated the intake air and did not see the temperature rise it wanted, which points at the elements, the supply to them, or the sensor measuring the result.
Possible causes
- CommonFailed intake air heater element
- CommonFailed heater relay
- CommonCorroded high-current connections at the heater
- CommonBlown fuse or fusible link
- PossibleDamaged wiring
- RareFailed control module driver
- CommonIntake air temperature sensor reading inaccurately
What you might notice
- Hard starting when cold
- White smoke on a cold start
- Rough running for the first minute
- Poor cold performance
- No symptom at all in warm weather
What to check, in order
- Watch the intake air temperature while the heater runs on a cold start - it should rise noticeably.
- Check the intake air temperature sensor reads plausibly before blaming the heaters.
- Test on a genuinely cold engine. In warm weather a diesel will usually start acceptably without the intake heater, which is why these faults go unnoticed until winter.
- Check the fuse or fusible link and the relay. These circuits carry very high current and their connections suffer for it.
- Inspect the heater terminals for corrosion and heat damage.
- Measure the heater element resistance against specification.
- Check for voltage at the heater during a cold start.
Read this code from your own car
Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.
Where this code sits
P00xxP01xxP02xxP03xxP04xxP05xxP06xxP07xxP08xxP09xxP0AxxP0BxxP0CxxP0DxxP0ExxP0FxxP10xxP11xxP12xxP13xxP14xxP15xxP16xxP17xxP18xxP19xxP1AxxP1BxxP1CxxP1DxxP1ExxP1FxxP20xxP21xxP22xxP23xxP24xxP25xxP26xxP27xxP28xxP29xxP2AxxP2BxxP2CxxP2DxxP2ExxP2FxxP30xxP31xxP32xxP33xxP34xxP35xxP36xxP37xxP38xxP39xxP3AxxP3BxxP3CxxP3DxxP3ExxP3Fxx
Computer output circuits and control module
P2600P2601P2602P2603P2604P2605P2606P2607P2608P2609P2610P2611P2612P2613P2614P2615P2616P2617P2618P2619P2620P2621P2622P2623P2624P2625P2626P2627P2628P2629P2630P2631P2632P2633P2634P2635P2636P2637P2638P2639P2640P2641P2642P2643P2644P2645P2646P2647P2648P2649P2650P2651P2652P2653P2654P2655P2656P2657P2658P2659P2660P2661P2662P2663P2664P2665P2666P2667P2668P2669P2670P2671