Powertrain, generic (extended)

P2609 Intake Air Heater System Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P2609 judges the intake air heating as a whole rather than one circuit: the controller compares what the grid heater should achieve with what it measures, for example via the current drawn or the rise in intake air temperature during preheat. Ram has published two service documents for its 6.7 L Cummins pickups. Bulletin 18-012-12 REV. A reflashes the engine module of 2011 Ram 2500/3500 trucks, with P2609 among the codes whose diagnosis was improved. A 2016 parts tip for 2012-2016 engines says that with heater faults or P2609 together with P0542 the heater grid and its relay are to be replaced as a set, and the cable between them checked for overheating. Volvo's 2022 pre-heat relay instruction also covers P2609-00. Hard cold starts and white smoke are the usual complaints.

Likely causes

Worn heater grid or relay (replace as a set)
Overheated or loose supply cable between relay and grid
Engine software with an outdated diagnostic (reflash available)
Intake air temperature sensor reading implausibly

Symptoms

  • Hard starting in cold weather
  • White smoke and rough idle after a cold start
  • MIL on

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€0–800
Time0.3–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

intake air heaterintake air temperature sensorheater relay

Related codes

P0540P0542P2604P2605P2606

References: static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov.