B1683
Mirror Driver/Passenger Switch Circuit Failure
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 mirror control switch isn't communicating properly with the vehicle's electrical system, like a light switch that's broken and can't turn the lights on or off. The ECU detects an open or short circuit in the mirror adjustment switch wiring or the switch itself has failed.

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Symptoms You May Notice
3 known symptoms for this code
Mirror adjustment buttons not responding or working intermittently
One or both mirrors cannot be adjusted in any direction
Dashboard warning light or fault indicator illuminated
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Embedded Systems Insight
What the ECU/ECM is actually computing

The ECU monitors voltage and resistance changes when the mirror switch is pressed, expecting specific signal patterns for each adjustment direction. If the circuit remains open, shorted, or shows abnormal resistance outside expected ranges, the ECU logs a failure. The module expects clean digital or analog signals that toggle between ground and 12V depending on switch position.

Voltage & Parameter Thresholds

Parameter Normal Range Fault Condition
Switch Circuit Voltage 0-12V with clean transitions No voltage change, stuck voltage, or continuous short
Circuit Resistance 50-5000 ohms (varies by design) Open circuit (infinite) or short (near 0 ohms)
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Diagnostic & DIY Fix Guide
Check these in order — from cheapest to most complex
1
Mirror switch connector
Disconnect and reconnect the mirror switch harness; clean terminals with electrical contact cleaner to remove corrosion.
2
Mirror control switch assembly
Replace the faulty switch unit after confirming wiring is intact using a multimeter continuity test.
3
Mirror switch wiring harness
Inspect for pinched, cracked, or damaged wire insulation along the door frame; repair or replace damaged segments.