P2605 OBD-II Trouble Code: Intake Air Heater A Circuit

Check Engine Light

P2605 code definition

The P2605 code gets stored when the PCM detects an irregular voltage reading originating from a certain intake air heater circuit.

What the P2605 code means

Voltage variations that fall outside of the parameters set forth by the manufacturer will trigger a stored code and, usually, a Check Engine Light. However, some vehicles will hold off on the Check Engine Light until there have been multiple (usually three) drive cycles that registered this problem.

Your vehicle’s intake air heater system warms air that enters the engine intake system so it can be put to the most efficient use. In order to do this, the intake heater system needs various electrical components to heat the air.

What causes the P2605 code?

The most common reason for a P2605 code to be stored is that your intake heater relay has become faulty.

Other causes include:

  • Open or shorted wires
  • Open or shorted connectors
  • An intake air temperature sensor that is broken or disconnected
  • A faulty intake air heater blower
  • The heater element has burned out
  • The PCM isn’t working correctly (very rare)

What are the symptoms of the P2605 code?

There aren’t really any symptoms associated with this code that most drivers would notice. Aside from the Check Engine Light we mentioned above, you probably won’t be aware of your vehicle acting any differently, though your engine may actually be underperforming.

How does a mechanic diagnose the P2605 code?

Your mechanic will use a scanner to retrieve whichever codes have been stored by your PCM. They’ll most likely use an ohmmeter and an infrared thermometer with a laser too. To begin with, they’ll examine wires and connectors and then use the scanner and record all freeze frame data and stored codes. After that, they’ll take the vehicle for a test drive to see if the code returns.

If the problem is still present, the mechanic will connect the scanner and crank the engine to see if the PCM commands the intake air heater to turn “ON.” They’ll then inspect the heating element to see if it’s finally warming up. Lastly, if the heating element remains cold, it will be time to check power sources for problems.

Common mistakes when diagnosing the P2605 code

If a mechanic rushes to judgment about the intake air heater’s problem – generally oversimplifying it – the repair may have a temporary effect, but the P2605 code will return. Each possibility for why the component isn’t working must be tested to make sure it’s fixed properly the first time.

How serious is the P2605 code?

The problems behind this code really aren’t that serious. However, it is worrisome that your vehicle probably won’t be performing as well as you’re used to without your noticing until the Check Engine light comes on. So although your safety won’t be at risk because the intake air heater system isn’t working correctly, it will cost you in performance and therefore getting it fixed should still be treated as a priority.

What repairs can fix the P2605 code?

The most common ways to fix the P2605 code are:

In very rare cases, it may be necessary to replace your vehicle’s PCM.

Additional comments for consideration regarding the P2605 code

Always be careful when testing the temperature of the heating element. Once it’s fixed, it may all of a sudden heat up quickly and burn you. This is why an infrared thermostat that uses a laser is so helpful – you can test for heat without putting yourself at risk.

Need help with a P2605 code?

To speak with a service advisor about P2605 code and how YourMechanic can help, just call 1-800-701-6230 or book an appointment with us online. We’ll provide you with a quote ASAP and schedule a time when one of our certified mobile mechanics can work on your car. They can meet you at your home or place of business and carry out the repairs on the spot!

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

More related articles

Veteran and Military Driver Laws and Benefits in New Mexico
The state of New Mexico offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...

Related questions

Q: Car jerking with flashing check engine light.

If your Check Engine Light is flashing, you need to stop driving it until it is fixed. A flashing Check Engine Light is warning you that there is a fire danger because there is to much raw fuel entering the...

Q: Constant KA issues....

Well you have a new fuel injector, coil pack, and spark plug wires. Were the spark plugs changed? The condition of the plugs must be checked as a small crack in the plugs porcelain can cause spark to leak and...

Q: Is it the part or a deeper problem when the camshaft position sensor error displays after replacement

As a technician, anytime two sensors fail at once, I suspect there is something that both these sensors have in common. This common item is the likely point of failure. It is unlikely that two sensors would fail at the...