Code
B1737
Other
B — Body
Mirror Driver Horizontal Switch Circuit Failure
AI status
Completed
Completed
100%
Causes
- Blown fuse or lost power to mirror switch/motor circuit
- Open or shorted wiring between the driver mirror switch and mirror/mirror control module
- Corroded, bent or loose connector pins at the switch or mirror assembly
- Failed driver‑side mirror horizontal switch (internal contacts worn or damaged)
- Failed mirror motor or internal gearbox preventing expected load/signal
- Faulty mirror control module or related body control module
Symptoms
- Driver mirror will not move left/right (horizontal)
- Mirror moves intermittently or only in one direction
- Clicking, no movement, or motor humming without travel
- Other mirror functions (vertical/heat/fold) may still work or may be affected
- Diagnostic trouble light or message relating to mirror system in some vehicles
What to check
- Verify stored DTCs and freeze‑frame data with a scan tool
- Check relevant fuses and relays for mirror/mirror control circuit
- Visually inspect door trim, switch and mirror connectors for corrosion, water, pin damage or loose pins
- Operate the horizontal switch while observing connector and wiring for movement/loose contact
- Measure supply voltage and ground at the mirror switch connector with switch operated
- Check continuity/resistance of switch terminals and between switch and mirror/control module
Signal parameters
- Supply voltage to switch: battery/ignition feed (nominally ~12 V) when circuit powered
- Switch output/logic: changes state when actuated — expect a measurable change in voltage or continuity from resting to actuated
- Closed‑switch resistance: near 0 ohms between appropriate switch terminals when actuated
- Open‑switch resistance: very high/OL when not actuated
- Motor current: increases when motor is commanded (compare to spec) — excessive current may indicate jammed motor/gearing
- Pulse or logic signal (if vehicle uses module control): toggles between 0 and reference voltage when commanded
Diagnostic algorithm
- Record the code and any vehicle symptoms; attempt to reproduce the fault
- Check fuses and power/ground at the mirror switch and mirror motor connector
- With a DVOM/oscilloscope and safety precautions, probe the switch connector while operating the horizontal control and confirm the expected voltage change/continuity
- If switch signal is absent at the switch, trace wiring back to the fuse and module checking for open/short/poor ground
- If switch produces correct signals, disconnect mirror assembly and check motor operation by applying correct, fused 12 V directly to horizontal motor terminals (bench test)
- Inspect and wiggle connectors, harness through the door hinge, and switch plug while operating switch to find intermittent faults
- If wiring and motor test good, test or substitute a known‑good switch or inspect the mirror control/body control module inputs and outputs with a scan tool
- Repair or replace damaged wiring, connectors, switch, motor or module as indicated; secure and protect harness to prevent recurrence
- Clear codes and retest full range of mirror movement and road/test cycle to verify repair
Likely causes
- Faulty horizontal switch (most common)
- Broken/shorted wiring or poor connector at mirror or switch
- Corrosion or pin damage at connector
- Blown fuse or poor power/ground
- Failed mirror motor or mirror control module (less common)
Fault status
Status
Driver mirror horizontal switch circuit fault detected — open/short/invalid signal between driver mirror switch and control module.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
Similar codes
Repair manuals
Brands with available manuals
6,990
The library contains 6,990 repair and diagnostic manuals. Choose a brand to open the full manual tree by year, model and trim.
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email