Code Definition

B1638 — Mirror Driver Right Short To Ground

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

About B1638

B1638 is a manufacturer-specific body diagnostic trouble code. It belongs to the B-prefix family of codes, which covers body, interior, airbag, or comfort-electronics faults.

When B1638 is stored, the module has detected a short-circuit (voltage pulled to ground or to supply) 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.

B1638 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

The Body Control Module (BCM) or door control module monitors the output driver circuit that controls the right side outside mirror motor. DTC B1638 is set when the module detects that one of the mirror motor driver outputs is shorted to ground, meaning excessive current is flowing on the output line because the load has effectively been bypassed. The module senses this as an over current condition and disables the affected driver to prevent damage to the output stage. When this code is set, the right side mirror typically fails to move correctly, the motor may stall against the short, and on ...

Join TaT to view the complete code information and diagnostic details.

Quick Facts