P2605Intake Air Heater B Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P2605 points to an open circuit at intake air heater B, a second heating element in the intake of a diesel engine; the control unit finds no current path through the element, its relay or the cabling. Volvo's EMS code lists keep heaters A, B and C apart. An August 2020 Volvo software change log for heavy-truck engines names P2605-13 among the codes tied to a preheater relay robustness problem, and a 2022 Volvo/Mack instruction for 11 L and 13 L engines asks for terminal tension checks at element and relay and a software check before relay and supply cable are renewed together. CARB expects intake air heater circuits to be watched for current and voltage drop. P0543 is the open-circuit code of heater A, P2CE1 that of heater C. Harder cold starts and white smoke follow.
- What you may notice
- Hard starting in cold weather
- White smoke after a cold start
- MIL on
- Likely causes
- LikelyLoose, corroded or burnt terminal at heater element or relay
- PossiblePreheat relay no longer switching
- PossibleHeater element B burnt through
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €60 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.