B1982

Driver's Door Unlock Relay Circuit Failure

Body Chassis/Safety Door lock control 🟢 Low — Fix at next service ✅ Safe to Drive
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What This Actually Means

In plain language — no jargon

The driver's door unlock relay isn't working properly, preventing the door from unlocking electronically. Think of it like a broken light switch that can't complete the circuit to turn the light on.

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Symptoms You May Notice

3 known symptoms for this code
Driver's door won't unlock using the power lock button or remote
Door unlock relay clicks or doesn't engage when attempting to unlock
Other doors unlock normally while driver's door remains locked
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How Your ECU Detects This

Technical sensor logic and voltage thresholds

The ECU monitors voltage and current flow through the driver's door unlock relay circuit when the unlock command is activated. It detects if the relay coil receives proper voltage, whether the relay contact closes, and if current flows to the unlock actuator motor.

Voltage & Parameter Thresholds

ParameterNormal RangeFault Condition
Relay Coil Voltage 11-14V when activated <9V or >15V, or no voltage change
Unlock Actuator Current Draw 2-8 amps during unlock cycle <0.5A or >12A, indicating open/short circuit
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Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex
1
Driver's door unlock relay
Locate the relay in the door module or under-dash fuse box and swap with an identical relay from another circuit to test; if door unlocks, replace with new relay.
2
Wiring harness and connectors
Inspect the wiring between the power lock switch and driver's door module for corrosion, loose connections, or damaged insulation and repair as needed.
3
Door lock actuator motor
Test actuator with direct 12V power; if it doesn't respond, the motor is faulty and must be replaced.
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When to See a Professional Mechanic

Not all fault codes are safe to DIY

Code B1982 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 B1982

What happens after you fix the fault

Once the fault is repaired, B1982 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.