P2605
Intake Air Heater "A" Circuit/Open
- Severity
- Low
- Driving
- Drivable — book it in
The intake air heater "A" circuit is open - a broken connection, a blown fusible link, or a failed element. On a diesel this heater warms the incoming air so the engine starts and runs cleanly when cold, and with the circuit open it is doing nothing at all.
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
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
- Check the fusible link first. These carry a very high current and are a common failure point.
- 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