What Does B1773 Mean?
This code indicates the Body Control Module (BCM) has detected a malfunction in the electrical circuit controlling the upward movement of the driver's side power mirror. The BCM monitors voltage and current flow in the mirror motor circuit and has identified an open circuit, short circuit, or abnormal resistance that prevents proper upward mirror adjustment. This is a manufacturer-specific body control code related to the comfort and convenience system.
Common Causes
40%
Failed driver side mirror motor assembly or internal motor winding open/short
30%
Damaged wiring harness or connector between door and mirror assembly due to flexing/water intrusion
20%
Faulty mirror control switch with internal contact failure in up position circuit
10%
Body Control Module internal driver circuit failure or corroded BCM connector pins
Diagnostic Steps
1
Step 1: Perform visual inspection of driver side mirror assembly for physical damage, water intrusion, or corrosion. Check mirror connector at door for pushed-out pins, corrosion, or moisture. Wiggle connector while attempting mirror operation to identify intermittent connection
2
Step 2: Using a multimeter, backprobe the mirror motor connector and command mirror up movement via scan tool active test or switch. Verify battery voltage (12-14V) is present at motor supply wire when up command is active. If no voltage present, problem is upstream in switch or BCM
3
Step 3: If voltage is present at motor, check ground circuit continuity and resistance (should be less than 1 ohm to chassis ground). Disconnect mirror connector and measure resistance across mirror motor terminals (typically 3-8 ohms for up circuit). Infinite resistance indicates open motor winding
4
Step 4: Test mirror control switch by measuring continuity between switch terminals in up position per wiring diagram. If switch tests good and mirror motor tests good, check door harness for breaks by measuring continuity from BCM connector through door boot to mirror connector while flexing door open/closed
5
Step 5: If all wiring and components test good, suspect BCM internal fault. Verify BCM connector pins are clean and tight. Clear code and retest operation. If code returns immediately with all circuits testing normal, BCM replacement is required
6
Step 6: After repair, clear codes, cycle mirror through all positions multiple times, and perform three complete drive cycles to verify repair. Recheck for code recurrence
Estimated Repair Cost
$75 - $450
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected a malfunction in the electrical circuit controlling the upward movement of the driver's side power mirror. The BCM monitors voltage and current flow in the mirror motor circuit and has identified an open circuit, short circuit, or abnorm...
The most common cause of B1773 (Mirror Driver Up Circuit Failure) is: Failed driver side mirror motor assembly or internal motor winding open/short
Typical repair costs for B1773 range from $75 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to continue driving as this only affects mirror adjustment convenience feature. Repair at convenience, though proper mirror adjustment is important for safe lane changes and backing maneuvers.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1773 to identify the root cause.
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Quick Info
Category
Body
System
Body Control and Convenience Systems
Difficulty
Type
Manufacturer
Recommended Tools
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