Code Definition

B1540 — Mirror Driver Switch Assembly Circuit Open

System: Body  |  Type: Manufacturer-Specific  |  Make: Ford

About B1540

B1540 is a manufacturer-specific body diagnostic trouble code recorded for Ford vehicles. It belongs to the B-prefix family of codes, which covers body, interior, airbag, or comfort-electronics faults.

When B1540 is stored, the module has detected an open (broken or disconnected) electrical path in the monitored circuit.

Scanning & clearing: Body (B) codes are often stored in the body control module, airbag module, or climate module. A basic OBD-II tool usually will not read body codes — an enhanced or OEM-level scan tool is typically required.

B1540 is a manufacturer-specific code. The same code string on a different make may have a different meaning. Always confirm the code's definition against the vehicle's service information for the specific make and model under test.

Code Information

This code relates to the Mirror Driver Switch Assembly circuit, the electric mirror control switch mounted in the driver door trim panel. The switch contains internal contacts that select either the left or right side mirror and route 12V power and ground signals to the chosen mirror motor windings based on the driver's directional input. The Body Control Module (BCM), or in some applications the Driver Door Module, monitors the switch input lines, and sets B1540 specifically when it detects an open circuit condition in the mirror driver switch assembly circuit. When this code is set, the affe...

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