Failed intake air heater element 'B' (open or shorted internally); Damaged or corroded wiring harness or connector at the heater; Blown fuse or faulty relay supplying power to the heater circuit; Poor ground connection for the heater circuit; Faulty intake air temperature sensor or related wiring; Engine control module software issue or internal fault (less common)

DTC codes / P26xx · Computer and output circuits / P2607

P2607Intake Air Heater 'B' Circuit Low

Q: What does code P2607 mean?

Intake Air Heater 'B' Circuit Low. P2607 indicates that the engine control module has detected a low-voltage condition on the intake air heater 'B' circuit, which is typically a second heating element used to warm incoming air on diesel engines during cold starts. The computer monitors the circuit and sets this code when the voltage signal falls below the expected threshold, indicating a short to ground, an open circuit, or a faulty component.

P2607 indicates that the engine control module has detected a low-voltage condition on the intake air heater 'B' circuit, which is typically a second heating element used to warm incoming air on diesel engines during cold starts. The computer monitors the circuit and sets this code when the voltage signal falls below the expected threshold, indicating a short to ground, an open circuit, or a faulty component.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaComputer and output circuits

Symptoms you may notice

Illuminated check engine light, often with no other noticeable symptoms
Hard starting or rough idle when the engine is cold
Excessive white smoke from the exhaust after a cold start
Reduced engine performance or hesitation until the engine warms up
Increased fuel consumption during warm-up
In rare cases, the engine may enter limp mode or fail to start in very cold weather

Common causes, most likely first

Failed intake air heater element 'B' (open or shorted internally)
Damaged or corroded wiring harness or connector at the heater
Blown fuse or faulty relay supplying power to the heater circuit
Poor ground connection for the heater circuit
Faulty intake air temperature sensor or related wiring
Engine control module software issue or internal fault (less common)

How to diagnose and fix it

Check the fuse and relay for the intake air heater circuit and replace if blown or faulty
Inspect the wiring harness and connector at the heater for damage, corrosion, or loose pins
Measure resistance of the intake air heater element 'B' and compare to manufacturer specifications
Test for voltage and ground at the heater connector with the key on and engine cold
Check the intake air temperature sensor signal for accuracy and wiring integrity
If all electrical checks pass, consult factory service information for specific pinpoint tests
Replace the intake air heater element or repair wiring as needed, then clear codes and verify

What the code does not always mean

A low circuit code often results from a poor ground connection rather than a failed heater element, so inspect ground points before replacing parts.
On some vehicles, the intake air heater is controlled by the glow plug control module, and a fault there can set P2607 even if the heater itself is good.
The heater circuit may only be active during cold starts, so a fault can be intermittent and not present during warm shop testing.
Aftermarket accessories or poor previous repairs to the harness can introduce resistance that triggers this code without any component failure.
Always verify the intake air temperature sensor reading matches ambient temperature when cold, as a skewed sensor can cause the module to misjudge heater circuit voltage.

Can I keep driving with P2607?

You can generally drive with this code, but cold-start performance and emissions may be affected, and in severe cold the engine may be hard to start. Avoid heavy load or long idling until repaired, and address the issue promptly to prevent further electrical damage.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.