B1744
Mirror Passenger Vertical Switch Circuit Short To Ground
Body Chassis/Safety Mirror Control System 🟢 Low — Fix at next service
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What This Actually Means
In plain language — no jargon

The passenger side mirror's vertical adjustment switch is sending a constant ground signal to the ECU, like a stuck button that won't let go. This prevents the mirror from responding to your up/down commands.

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Symptoms You May Notice
3 known symptoms for this code
Passenger mirror will not move up or down
Mirror control switch unresponsive or stuck in one position
Warning light or fault code displayed on dashboard
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Embedded Systems Insight
What the ECU/ECM is actually computing

The ECU monitors the voltage signal from the passenger mirror vertical switch circuit. It expects the switch to toggle between high and low voltage states when activated. A short to ground causes the signal to remain at 0V continuously, preventing the ECU from recognizing normal switch commands.

Voltage & Parameter Thresholds

Parameter Normal Range Fault Condition
Switch Signal Voltage 5V (inactive) to 0V (active) toggle pattern Constant 0V (stuck at ground)
Circuit Resistance 100-10,000 ohms depending on switch state Less than 10 ohms (direct short)
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Diagnostic & DIY Fix Guide
Check these in order — from cheapest to most complex
1
Mirror control switch connector
Disconnect and reconnect the passenger mirror switch harness to eliminate corrosion or loose contact.
2
Mirror control switch assembly
Replace the faulty vertical switch unit in the driver's control panel if connector is clean.
3
Wiring harness and connectors
Inspect the wire path from switch to ECU for damage, pinches, or exposed copper causing ground contact.