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B2107 OBD-II Trouble Code: Front Wiper Motor Relay Circuit Short to Vbatt

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B2107 code definition

The B2107 trouble code notes a front wiper motor relay circuit failure.

What the B2107 code means

The B2107 code is a generic OBD-II body trouble code that detects a circuit error in the front wiper motor relay. The wiper motor relay acts as a switch for the vehicle’s front windshield wipers, and allows the wipers to operate at a predetermined speed. When the wiper control module receives an abnormal voltage reading from the front wiper motor relay circuit, then the B2107 trouble code may be stored.

What causes the B2107 code?

There are a few different issues that can cause the B2107 trouble code to be stored:

  • A damaged relay circuit
  • Damaged electrical components in the front wiper system
  • Failed front wiper relay
  • In rare cases, a defective wiper control module or powertrain control module (PCM)

What are the symptoms of the B2107 code?

When the B2107 trouble code is detected, it is likely that the front windshield wiper system will not operate properly. The wipers may work only intermittently, or they may not work at all. In some cases, the wipers may only work at one speed, and will not be adjustable. The code may also be accompanied by an illuminated check engine soon Warning Light on the vehicle’s gauge cluster.

How does a mechanic diagnose the B2107 code?

The B2107 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 B2107 code, while also checking to see if any other trouble codes have been detected. If the technician notes multiple present codes, then they will need to be addressed in the order that the scanner displays them in. The codes will then be reset and the vehicle restarted, so that the B2107 code can be checked for again. If the code is no longer present, then it was likely inaccurately detected, or is the result of an intermittent issue.

If the code remains present following the reset, then the electrical components in the windshield wiper system should be visually inspected, and any shorted wires, open connectors, or blown fuses will need to be replaced. The voltage to the circuit should then be tested, followed by an inspection of the front wiper relay.

After any components are repaired or replaced, the trouble codes will once again be reset, the vehicle restarted, and the B2107 code checked for again. By doing this, the technician will know as soon as the problem is fully resolved.

Common mistakes when diagnosing the B2107 code

The most commonly made mistake when diagnosing the B2107 code comes from a failure to properly adhere to the OBD-II trouble code diagnosis protocol. It is imperative that mechanics follow the protocol step by step at all times, to ensure thorough and efficient diagnoses, and accurate repairs.

Oftentimes fully functional front wiper relays are replaced because damaged electrical components were overlooked.

How serious is the B2107 code?

The B2107 code will not keep a car from being drivable, or present any drivability concerns. However, the windshield wipers will likely not work properly. The wipers may be erratic, or not work at all, which can cause both practicality and safety concerns when driving in wet conditions. When the B2107 code is detected, an inspection should be scheduled, and the vehicle should not be driven in rain, snow, or mist.

What repairs can fix the B2107 code?

Repairs for the B2107 trouble code include:

Additional comments for consideration regarding the B2107 code

The B2107 code is a manufacturer specific trouble code, which means that the definition can vary depending on the automaker. In many vehicles the B2107 code represents a front wiper motor relay circuit error, but in other cars this code can detect an entirely different body issue. As is always the case, the mechanic should take note of what car is being worked on when diagnosing the B2107 trouble code.

Need help with a B2107 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
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