B1289 code definition
The B1289 trouble code notes an error with the servo motor potentiometer air intake right circuit.
What the B1289 code means
The B1289 code is a generic OBD-II trouble code that suggests an issue with the servo motor potentiometer air intake circuit on the right side (the system has two interior air intake systems, a “left” one and a “right” one). The potentiometer is a voltage divider, which allows the interior air intake system to be adjustable, rather than just having an on or off switch. If a circuit malfunction is detected with the servo motor potentiometer air intake right, then the B1289 trouble code will be triggered.
What causes the B1289 code?
The B1289 trouble code can be the result of a few different things:
- Defective servo motor
- Malfunctioning potentiometer
- Damaged or defective electrical components
- In rare cases, a faulty climate control module, powertrain control module (PCM), or body control module
What are the symptoms of the B1289 code?
The B1289 trouble code may be accompanied by a blinking A/C light on the climate controls, or possibly an illuminated check engine soon Warning Light. It is very likely that the climate control system will not operate properly.
How does a mechanic diagnose the B1289 code?
The B1289 code will be diagnosed with an OBD-II trouble code scanner. A certified technician will use the scanner to view the freeze frame data for the B1289 code, and check for any additional trouble codes that are present. If there are multiple codes detected, then they should be diagnosed in the order in which they appear. The trouble codes will then be reset and the vehicle restarted, so the mechanic can see if the code remains detected. If the code is no longer present, then it likely represents an intermittent error, or was the result of an erroneous detection.
If the code remains detected, then the technician will begin by visually inspecting the electrical components. Any wires, connectors, or fuses that are damaged or defective will need to be replaced. The servo motor and potentiometer will then be inspected, and replaced if they are faulty.
Any time the mechanic replaces or repairs a component, the trouble codes will need to be reset, the car restarted, and the B1289 code checked for again. This will allow the mechanic to know as soon as the problem causing the code has been identified and repaired.
Common mistakes when diagnosing the B1289 code
The most common mistake when diagnosing the B1289 code is the failure to properly follow the OBD-II trouble code diagnosis protocol. The protocol should also be complied with, as it helps guarantee that diagnoses and repairs are accurate and efficient.
It is fairly common for damaged electrical components to be overlooked, and fully operational potentiometers and servo motors to be erroneously replaced.
How serious is the B1289 code?
The B1289 trouble code will not keep a car from being drivable, or present any drivability problems. However, the climate control system may not operate properly. As with all trouble codes, it’s important to have the vehicle inspected when the B1289 code is detected.
What repairs can fix the B1289 code?
Some potential repairs for the B1289 trouble code are:
- Servo motor replacement
- Potentiometer replacement
- Replacement of wires, connectors, and fuses
- In rare cases, replacement of the PCM, body control module, or climate control module
Additional comments for consideration regarding the B1289 code
It is highly unlikely that the B1289 trouble code is the result of a defective PCM, body control module, or climate control module. All potential causes of the code should be thoroughly checked for before any control module is condemned. If a controller does end up needing to be replaced, the mechanic will also need to reprogram it.
Need help with a B1289 code?
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This article originally appeared on YourMechanic.com as B1289 OBD-II Trouble Code: Servo Motor Potentiometer Air Intake Right Circuit Open and was authored by Brady Klopfer.