B1978 Passengers Front Seat Down Switch Circuit Short to Battery

OBD2 Code: B1978

Description: Passengers front seat down switch circuit short to battery.

Definition: This code indicates that there is a short circuit in the passenger’s front seat down switch circuit, which is causing it to connect directly to the battery. This can lead to unintended operation of the seat adjustment mechanism and may require inspection and repair of the wiring or switch involved.

B1978: Passengers front seat down switch circuit short to battery
Severity: Moderate

Common Causes

B1978 – Passengers Front Seat Down Switch Circuit Short to Battery

Common causes:

• Faulty passengers front seat down switch
• Short circuit in the wiring harness
• Faulty body control module (BCM)
• Corrosion or poor connections in the circuit

Common Misdiagnosis

OBD2 Code: B1978

Description: Passenger’s Front Seat Down Switch Circuit Short to Battery

Common Misdiagnosis: Replacing the seat switch without checking for wiring issues or a short circuit in the harness.

Common Diagnostic Steps

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OBD2 Code: B1978

Description: Passenger’s Front Seat Down Switch Circuit Short to Battery

• Inspect the wiring and connectors for damage or corrosion.
• Check for any blown fuses related to the seat control circuit.
• Test the passenger front seat down switch for proper operation.
• Measure voltage at the switch connector to identify a short to battery condition.
• Examine the seat control module for faults or malfunctions.
• If necessary, replace damaged components such as wiring, connectors, or switches.
• Clear the code and test drive to ensure it does not return.