B1776

Code

Other B — Body

Mirror Driver Up Circuit Short To Ground

Brand: Other

Type: B — Body

Views: UK: 24 EN: 39 RU: 21

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Page language: EN

Causes

Damaged or chafed wiring harness to mirror causing insulation fault
Corroded or pushed-back connector pins at mirror or module
Shorted mirror motor or actuator internal windings
Faulty mirror position/driver module or Body Control Module (BCM)
Water intrusion into mirror assembly or connector
Aftermarket accessories or improper repairs that tapped into the circuit

Symptoms

Mirror will not move upward (may move other directions)
Mirror movement is intermittent or only moves in one direction
DTC stored and possible warning/message in vehicle
Related fuse may blow or circuit protection may trip
Unusual noise from mirror area when attempting to move

What to check

Retrieve freeze frame and any related mirror codes from BCM or body module
Visually inspect wiring, grommets, and connectors for damage, corrosion, or water
Check related fuse(s) and circuit protection devices
With ignition on, command mirror up and measure voltage at mirror connector
Perform continuity test from suspect circuit to chassis ground with connector disconnected
Disconnect mirror assembly; check if DTC clears or changes

Signal parameters

No command: driver output should be inactive (no output voltage on up terminal)
When 'up' commanded: control module should apply approx. battery voltage to the motor/driver feed for that direction
If short to ground: voltage at the circuit will remain near 0 V during the 'up' command
Motor/actuator coil resistance should be finite (not near 0 Ω). A near-zero resistance indicates a direct short
Excessive current draw during command (higher than nominal) indicates motor short or wiring short

Diagnostic algorithm

Record stored codes and any freeze-frame data. Note vehicle conditions and attempt the mirror up operation while observing behavior.
Visually inspect the mirror assembly, harness, and routing for damage, pinched sections, or water ingress. Inspect connectors for corrosion or pushed-back pins.
Check related fuses and replace if blown. If fuse repeatedly blows, suspect shorted circuit or motor.
With ignition on, backprobe the mirror 'up' control pin at the mirror connector. Command 'up' and measure voltage. If voltage remains near 0 V, suspect short to ground between module and mirror or a shorted output driver.
Disconnect the mirror assembly and re-test. If the DTC clears and voltage behavior normalizes, the fault is in the mirror assembly (motor/actuator or internal wiring). If code remains, fault is upstream (wiring, connector, BCM).
Perform a resistance/continuity check from the control module pin to chassis ground with the circuit disconnected. Low resistance (close to 0 Ω) indicates a short to ground.
If no direct short found, inspect and wiggle harness while monitoring circuit for intermittent short. Repair any chafed sections, replace damaged connectors or grommets.
If wiring and connectors check good, test or substitute the mirror motor/actuator and/or mirror switch. If fault persists after replacing mirror components, suspect BCM/driver failure and verify with manufacturer-specific procedures before module replacement.
After repairs, clear codes and verify proper mirror operation through several cycles and re-check for stored codes.