B1733
Mirror Driver Vertical Switch Circuit Failure
Body Chassis/Safety Mirror Control 🟢 Low — Fix at next service
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What This Actually Means
In plain language — no jargon

The vertical control switch in your side mirror isn't sending the right electrical signal to the car's computer, like a light switch that's broken and won't tell the system whether it's on or off. This prevents the mirror from moving up and down properly.

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Symptoms You May Notice
3 known symptoms for this code
Driver side mirror won't move vertically up or down
Mirror control switch is unresponsive or intermittent
Warning light or fault indicator illuminates on dashboard
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Embedded Systems Insight
What the ECU/ECM is actually computing

The ECU monitors the voltage signal from the mirror vertical switch circuit to detect valid control inputs. It expects a clean digital or analog signal within specific voltage ranges when the switch is activated. If the signal is absent, shorted, or out of range for too long, the fault is logged.

Voltage & Parameter Thresholds

Parameter Normal Range Fault Condition
Switch Signal Voltage 0-5V with clean transitions Out of range, stuck, or no signal detected
Circuit Continuity Continuous path with <5Ω resistance Open circuit or >10Ω resistance
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Diagnostic & DIY Fix Guide
Check these in order — from cheapest to most complex
1
Mirror control switch connector
Inspect and reseat the connector at the mirror assembly for corrosion or loose pins.
2
Wiring harness (mirror vertical circuit)
Check for pinched, corroded, or broken wires between the switch and ECU.
3
Mirror vertical motor switch assembly
Replace the switch if electrical continuity and connectors check out but signal is still missing.