Intake Air Heater Circuit Range/Performance
The P2606 code indicates that the powertrain control module (PCM) has detected a malfunction in the intake air heater circuit, specifically a range or performance issue. The intake air heater is used in diesel engines to warm the incoming air for better cold-start performance and reduced emissions. This code sets when the PCM detects that the heater circuit's resistance or current draw is outside the expected range, often due to a faulty heater element, relay, or wiring problem.
01. Most Common Causes
- Faulty intake air heater element
- Open or shorted wiring in the heater circuit
- Failed intake air heater relay
- Corroded or loose electrical connectors
- Blown fuse for the intake air heater circuit
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Hard starting in cold weather
- Rough idle or hesitation during cold start
- Excessive white smoke from exhaust on cold start
- Reduced fuel economy
03. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for additional codes.
Step 2: Visually inspect the intake air heater, wiring, and connectors for damage, corrosion, or loose connections.
Step 3: Test the intake air heater relay and fuse with a multimeter.
Step 4: Measure resistance across the heater element terminals; compare to manufacturer specifications.
Step 5: Check for voltage at the heater connector with the ignition on; if no voltage, trace the circuit back to the relay and PCM.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is generally safe to drive short distances, but cold-start performance may be poor, and emissions could increase. Prolonged driving may cause additional strain on the engine and reduce fuel economy.
How much does it cost to fix?▼
The cost to fix P2606 typically ranges from $50 to $150 for parts and labor, depending on whether the heater element, relay, or wiring needs replacement.