B1976 code definition
The B1976 trouble code detects a passenger seat forward switch circuit error.
What the B1976 code means
The B1976 code is a standard OBD-II trouble code that notes a circuit malfunction from the passenger seat forward switch. The passenger seat forward switch controls the horizontal movement of the front passenger seat. When the switch, which is usually located on the outboard side of the passenger seat, is deployed, the seat will move forward. If the body control module or powertrain control module (PCM) detect a circuit error from the passenger seat forward switch, then it is likely that the B1976 trouble code will be stored.
What causes the B1976 code?
The B1976 trouble code is commonly caused by one of two issues. The first cause is damaged electrical parts, such as blown fuses, shorted wires, and open connectors. These electrical parts can be in the passenger seat forward switch, or in the power seat system. The second common cause is a malfunctioning passenger seat forward switch. While quite rare, the code is also sometimes triggered by a defective body control module.
What are the symptoms of the B1976 code?
A vehicle that has a detected B1976 trouble code will almost always have an inoperable seat forward switch for the front passenger seat, which means the seat cannot be adjusted forward. It is also likely that the seat cannot be adjusted rearward, either. In many cases, this code is also accompanied by the check engine soon warning light illuminating on the vehicle’s gauge cluster.
How does a mechanic diagnose the B1976 code?
The B1976 code will be diagnosed using a standard OBD-II trouble code scanner. A certified technician will use the scanner to look at the freeze frame data and gather information about the code, while also checking to see if any other trouble codes are present. If multiple codes are detected, then the mechanic will inspect them in the order that they are displayed in. The trouble codes should then be reset, and the vehicle restarted, so the B1976 code can be searched for. If the code is no longer present, then it was likely detected inaccurately, or represents an intermittent error.
If the B1976 code remains, then the mechanic will begin by visually inspecting all of the electrical components in the passenger seat forward switch and power seat systems. All damaged or otherwise compromised parts will need to be replaced. If all of the electrical components are in good, working order, then the passenger seat forward switch has most likely failed.
After any parts are replaced or repaired, the trouble codes should once more be reset, the vehicle restarted, and the code checked for. By doing this, the technician will know as soon as the problem has been fully resolved.
Common mistakes when diagnosing the B1976 code
The most common mistake that is made in diagnosing the B1976 trouble code is the failure to properly comply with the OBD-II diagnosis protocol. It is imperative that mechanics follow the protocol at all times, to help ensure accurate diagnoses and repairs.
It is fairly common for electrical failures to be overlooked, and passenger seat forward switches to be unnecessarily replaced as a result.
How serious is the B1976 code?
The B1976 trouble code will not present any drivability issues, but the front passenger seat will likely not be able to be adjusted forward or rearward. If the seat is stuck too far forward, it may be inaccessible for the passenger. If the seat is stuck too far rearward, it may be unsafe for a passenger, as the airbag may not reach the person (it also may render the backseat unusable in this position). When the code is detected, an inspection should be scheduled.
What repairs can fix the B1976 code?
Repairs for the B1976 trouble code include:
- Replacement of wires, connectors, and fuses
- Replacement of the passenger seat forward switch
- In rare cases, replacement of the body control module
Additional comments for consideration regarding the B1976 code
This code is a manufacturer specific trouble code, which means that the definition varies from automaker to automaker. The B1976 code suggests a passenger seat forward switch circuit malfunction in some vehicles, but an entirely different body problem in other vehicles. As always, the mechanic should be aware of the vehicle that is being worked on when diagnosing this trouble code.
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