P2607 OBD-II Trouble Code: Intake Air Heater 'B' Circulation Low

P2607 code definition

The P2607 trouble code is a generic powertrain code related to computer circuit output issues. Your vehicle’s engine control module (ECM) is receiving a notification that the second intake air heater (heater B or 2) is presenting a low voltage reading or is exceeding the manufacturer’s allowed variances.

The P2607 code is also related to:

• P2606: Intake Air Heater B Circuit Range/Performance
• P2608: Intake Air Heater B Circuit High
• P2609: Intake Air Heater System Performance

What the P2607 Code Means

When a P2607 code comes up, your vehicle’s air intake heater B (number 2 intake heater circuit) is not receiving the correct voltage. An intake air heater system works to warm the cooler air coming into the intake system.

The resistance between the signal and return posts of the air intake heater relay should be between 15 and 25 ohms. The resistance of the air intake heater relay signal circuit between the vehicle’s ECM and the intake air heater relay connector should have a resistance less than 10 ohms. If the ECM detects resistance levels lower than these readings, a P2607 code will appear.

What Causes the P2607 code?

• Damaged or defective intake heater relays located on the passenger side of the battery tray
• Loose or damaged electrical wires, including damage due to battery acid corrosion.
• Damaged or defective intake air heater blower
• Damaged, loose, or defective intake air temperature sensors
• Damaged, defective, or burned out heater element
• In rare cases, a damaged or defective ECM

What are the Symptoms of the P2607 Code?

Symptoms of a P2607 trouble code may include:

• Vehicle warning or Check Engine Light may illuminate, with no other symptoms present
• Vehicle may fail a smog test
• Vehicle may stall or shake at idle

How Does a Mechanic Diagnose the P2607 Code?

To diagnose a P2607 code, a mechanic may do one or more of the following:

• Use an OBD-II scanner to check for a stored P2607 trouble code

• Perform a visual inspection

• Check for damaged or defective wires

• Check battery wires for damage or loose connections

• Check for any loose electrical connectors or bent pins

• Check for any grounded wires

• Connect vehicle to scanner and check if the ECM is commanding the intake air heater to turn on

• Listen to hear if the blower is working

• Locate heater element and use an infrared thermometer to check if it is warming

• Measure resistance between signal and return posts of the intake air heater relay

• Measure resistance of the intake air heater relay signal circuit between the vehicle’s ECM connector and the intake air heater relay connector

• Measure the voltage between the signal circuit of the intake air heater and battery negative

• Check circuit continuity

• Clear the code and test drive the vehicle to see it reappears (with some makes and models, it requires a few drive cycles with a failure to turn on a warning light)

• Note: Some vehicle models will allow the mechanic to turn a vehicle’s air intake heater on and off, which is helpful for testing this issue after an engine is warm.

How Serious is the P2607 Code?

Because the vehicle may not show any symptoms for this code except a warning light or failed smog test, but could potentially stall or hesitate at idle causing dangerous driving conditions, YourMechanic considers the P2607 code serious and recommends to take your vehicle to your local service center or mechanic immediately for diagnosis and repair.

What Repairs can Fix the P2607 Code?

• Replace or repair any damaged or defective wires
• Replace or repair any damaged or loose connections in the battery wires
• Replace or repair damaged battery cable
• Replace or repair a damaged or defective air intake heater B (or number 2) relay
• Repair the air intake heater ground
• Replace or repair any damaged or defective temperature sensors
• Replace or repair any loose electrical connectors or bent pins
• Replace or repair any grounded wires
• Replace a damaged or defective heater element
• Repair or replace damaged or defective intake air heater B
• Repair or replace a defective or faulty ECM
• Clear the code and test drive the vehicle to see it reappears (with some makes and models, it requires a few drive cycles with a failure to turn on a warning light)

Need Help with a P2607 Code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.