Intake Air Heater Circuit/Open
The P2605 code indicates a problem in the intake air heater circuit, which is used to warm the incoming air in diesel engines for better cold starts. The Powertrain Control Module (PCM) has detected an open circuit or high resistance in the heater element or its wiring. This can prevent the heater from operating, leading to hard starting in cold weather and increased emissions.
01. Most Common Causes
- Open or shorted intake air heater element
- Faulty intake air heater relay
- Blown fuse or fusible link
- Damaged wiring or connectors in the heater circuit
02. Symptoms You Will Notice
- Hard starting in cold weather
- Check Engine Light illuminated
- Rough idle or poor performance until engine warms up
- Increased exhaust smoke during cold start
03. Step-by-Step Diagnosis
Step 1: Use a scan tool to confirm P2605 and check for related codes.
Step 2: Visually inspect the intake air heater element for damage or breakage.
Step 3: Test the heater relay and fuse with a multimeter for continuity and voltage.
Step 4: Check wiring and connectors for corrosion, looseness, or shorts.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
Yes, but you may experience hard starting in cold weather. It is safe to drive in warm conditions, but the issue should be repaired to avoid potential starting problems.
How much does it cost to fix?▼
Typically between $50 and $150 for parts and labor, depending on the specific cause and vehicle model.