Skip the auto shop - Our mechanics make house calls

B1242 OBD-II Trouble Code: Air Flow Recirculation Door Driver Circuit Failure

diagnostic check engine light

B1242 code definition

The B1242 trouble code detects an error with the air flow recirculation door driver.

What the B1242 code means

The B1242 code is a generic OBD-II trouble code that notes a circuit error with the air flow recirculation door driver. The air flow recirculation system is a crucial part of the heating, ventilation, and air conditioning (HVAC) system, as it helps recirculate air through the vehicle’s cabin. When the body control module or the powertrain control module (PCM) notes that the air control recirculation door driver is malfunctioning, then the B1242 code will be detected.

What causes the B1242 code?

The B1242 code can be caused by a few different things:

  • Defective air inlet door actuator motor
  • Damaged wires, connectors, or fuses in the HVAC module
  • Short circuit in the control lines
  • Faulty ground wire
  • Jammed air flow recirculation door
  • Defective HVAC module
  • In rare cases, defective PCM, body control module, or climate control module

What are the symptoms of the B1242 code?

The B1242 trouble code will likely be accompanied by the check engine soon Warning Light illuminating on the vehicle’s gauge cluster. There will likely also be problems with the climate control system, such as an inability to recirculate, or improper air temperature.

How does a mechanic diagnose the B1242 code?

The B1242 code will be diagnosed using a standard OBD-II trouble code scanner. A certified mechanic will use the scanner to view the freeze frame data and assess the B1242 code. The scanner will also be used to check for the presence of additional trouble codes. If the technician notices that there are multiple codes present, then they will need to be addressed in the order in which they are received. The mechanic will then reset the trouble codes, restart the vehicle, and check to see if the code is still present. If not, then the code was likely the cause of an intermittent error, or perhaps an inaccurate detection.

If the B1242 code remains detected, then the mechanic will begin with a visual inspection of all of the electrical components in the system. Any blown fuses, short wires, or open or corroded connectors will need to be replaced. The air flow recirculation door should then be inspected to make sure it is not jammed, and then the ground wire will be checked. If the issue is unresolved, then the problem is likely a faulty air inlet door actuator motor.

If the air inlet door actuator motor is not the problem, then the circuits and the HVAC system will need to be more thoroughly inspected.

After any component is replaced, the mechanic will need to reset the trouble codes, restart the vehicle, and again look for the presence of the B1242 code. By doing this, the mechanic will know as soon as the problem has been fixed.

Common mistakes when diagnosing the B1242 code

The most frequently made error when diagnosing the B1242 code comes from a failure to properly follow the OBD-II trouble code diagnosis protocol. It is very important that the mechanic abide by the protocol at all times, to help ensure inspections and repairs that are thorough and efficient.

It is fairly common for electrical malfunctions to be overlooked when diagnosing the B1242 code, which can lead to unnecessary repairs.

How serious is the B1242 code?

A vehicle with the B1242 trouble code will still be drivable, though the climate control system will likely be compromised. The vehicle should be inspected and repaired sooner rather than later.

What repairs can fix the B1242 code?

Repairs for the B1242 trouble code are:

  • Air inlet door actuator motor replacement
  • Replacement of electrical components
  • Ground wire replacement
  • Replacement of circuits in the control line
  • Removing the jam that is restricting the air flow recirculation door
  • In rare cases, replacing the HVAC module, PCM, climate control module, or body control module

Additional comments for consideration regarding the B1242 code

While the B1242 signals an air flow recirculation door driver circuit failure in many vehicles, the code can stand for a different issue in some makes and models.

Need help with a B1242 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.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

P0222 OBD-II Trouble Code: Throttle/Pedal Position Switch/Sensor B Circuit Low Input
P0222 code definition Throttle/Pedal Position Switch/Sensor B Circuit Low Input What the P0222...
Insurance Requirements for Car Registration in Kentucky
The Kentucky Transportation Cabinet requires that all drivers in Kentucky carry liability automotive insurance, or “financial responsibility” in order to operate a vehicle legally and maintain vehicle...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...


Related questions

Q: 1999 firebird every now and then dies while driving and low engine power light comes on

A bad mass airflow (MAF) sensor can cause loss of power, no starts, and lean or rich conditions. If cleaning the sensor did not get rid of the P0102 trouble code, then replace the MAF sensor and clear the...

Q: Check engine light on 1998 Audi A4

Any good mechanic can check them out. Here's the problem that you've got though--when there's a linking error, either the nanoport isn't working right because one of the pins is bent or there's wiring short somewhere in the computer system...

Q: All warnings lamps are shawn in dashboard, and the gauges the acceleration and rpm are on 0 , also

It sounds like you may have a dashboard integration unit failure, or a fault within the electrical control unit (ECU). It's also possible that the instrument cluster itself is faulty. Have the vehicle scanned for diagnostic trouble codes (DTCs)...