B1773

Mirror Driver Up Circuit Failure

Body Chassis/Safety Mirror Control 🟢 Low — Fix at next service ✅ Safe to Drive
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What This Actually Means

In plain language — no jargon

The mirror's up motor circuit isn't working properly—the ECU detected a short, open, or failed connection like a broken wire in a lamp circuit. The mirror motor won't move up when commanded.

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Symptoms You May Notice

3 known symptoms for this code
Driver side mirror won't move upward
Mirror control switch non-responsive in up direction
Warning light or fault indicator illuminated on dashboard
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How Your ECU Detects This

Technical sensor logic and voltage thresholds

The ECU monitors voltage and current flow through the mirror motor's up-direction circuit. It checks for proper voltage delivery and motor resistance during actuation. A fault triggers when voltage is missing, too high, or current draw is abnormal.

Voltage & Parameter Thresholds

ParameterNormal RangeFault Condition
Motor Circuit Voltage 10.5V - 14.5V when activated Below 4V or above 15V, or no voltage detected
Circuit Continuity/Resistance 20-80 ohms (motor coil) Open circuit (infinite ohms) or short to ground (<5 ohms)
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Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex
1
Wiring harness connectors
Inspect and reseat all connectors at the mirror motor and control module for corrosion or loose pins.
2
Mirror motor up wires
Check for pinched, frayed, or corroded wires in the door harness and repair or replace damaged sections.
3
Mirror motor assembly
Test motor with direct 12V supply; if unresponsive, replace the mirror motor unit.
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When to See a Professional Mechanic

Not all fault codes are safe to DIY

Code B1773 is a low-severity fault. Your vehicle is generally safe to drive to a workshop for diagnosis. However, do not ignore it indefinitely — low-severity codes often indicate developing problems that become expensive if neglected. Book a diagnostic appointment within 2–4 weeks. If you notice any additional symptoms (rough running, power loss, unusual smells), treat it as higher priority.

Safety note: OBD-II codes identify the system or circuit where a fault was detected — they do not always identify the exact failed component. A professional mechanic using live sensor data will diagnose the root cause more accurately than replacing parts based on the code alone.
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How to Clear Code B1773

What happens after you fix the fault

Once the fault is repaired, B1773 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.

The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.

✅ Safe to Clear When
  • Fault has been diagnosed and repaired
  • You want to confirm the repair worked
  • Code appeared after a sensor was cleaned
⚠️ Do Not Clear When
  • Preparing for an emissions/PUC test
  • Root cause is still undiagnosed
  • Check engine light is flashing
Emissions test note: Clearing codes resets OBD readiness monitors. Most vehicles need 50–100 km of mixed driving before monitors complete. Do not clear codes immediately before an emissions or PUC inspection.