B1736
Mirror Driver Vertical Switch Circuit Short To Ground
Body Chassis/Safety Mirror Control Circuit 🟢 Low — Fix at next service
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What This Actually Means
In plain language — no jargon

The driver's side mirror's vertical adjustment switch has an electrical short to ground, like a broken wire touching the metal frame. The mirror control module can't properly detect when you're trying to move the mirror up or down.

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Symptoms You May Notice
3 known symptoms for this code
Driver side mirror won't adjust vertically or moves erratically
Mirror control switch unresponsive or stuck in one position
Warning light illuminates on dashboard
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Embedded Systems Insight
What the ECU/ECM is actually computing

The ECU monitors voltage on the vertical switch circuit, expecting a clean signal that changes as you press the switch. When shorted to ground, the circuit voltage stays near 0V instead of toggling between high and low states, preventing normal switch detection.

Voltage & Parameter Thresholds

Parameter Normal Range Fault Condition
Switch Circuit Voltage 5V nominal with transitions 0-5V Stuck near 0V or continuously low
Circuit Resistance Open or high resistance when inactive Low resistance to ground (under 5 ohms)
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Diagnostic & DIY Fix Guide
Check these in order — from cheapest to most complex
1
Wiring harness connector
Disconnect and inspect the mirror control connector for corrosion, moisture, or pinched wires causing the short.
2
Vertical adjustment switch
Replace the faulty switch assembly if it has internal damage or insulation breakdown.
3
Mirror control module wiring
Repair or replace damaged wiring between the switch and control module if a cut or abraded section is found.