P2605 moderate

Intake Air Heater A Circuit Low

The P2605 code means the vehicle's onboard diagnostic system has detected: Intake Air Heater A Circuit Low. This is a moderate severity code.

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Keep driving?: Yes, but fix soon
DIY difficulty: moderate
Estimated cost: $200 - $600 (parts and labor)

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Common Symptoms

Extended cranking in cold weather
White exhaust smoke on startup
Glow plug or air heater indicator stays on long
Rough cold idle

Probable Causes (Ranked by Likelihood)

Short to ground in air heater circuit Very High
Failed air heater relay High
Damaged air heater element Moderate
Corroded heavy-gauge wiring connections Low

Step-by-Step Diagnostic Procedure

Check air heater circuit for shorts to ground
Test air heater relay operation
Measure heater element resistance
Inspect heavy-gauge wiring and bus bars for corrosion

Frequently Asked Questions

Can I still drive with P2605?

Yes, but cold starting will be difficult. Once the engine is warm it operates normally. Plan extra time for cold starts.

How much current does an intake air heater draw?

Intake air heaters draw substantial current, often 50-100 amps or more. This is why they use heavy relays and thick wiring.

Can a weak battery make P2605 worse?

Yes. The heater needs high current to work properly. A weak battery may not supply enough power, making the heater less effective even if it is not faulty.