B1982 — Driver’s Door Unlock Relay Circuit Failure #

The description of this code may vary depending on the vehicle manufacturer. Please refer to your specific OEM documentation for exact wording.

• Driver’s Door Unlock Relay Circuit Failure (Ford, Lincoln, Mercury)
• Driver Door Unlock Relay Malfunction (Mazda)
• Driver Side Door Unlock Relay Circuit Fault (Jaguar, Land Rover)

Summary of DTC B1982 #

Diagnostic Trouble Code (DTC) B1982 indicates a problem detected by the vehicle’s Body Control Module (BCM) with the driver’s door unlock relay circuit. The relay is an electrically operated switch that manages the power sent to the driver’s door lock actuator for unlocking. When the BCM senses abnormal voltage, open or short circuits, or no response from the relay during a lock/unlock command, it logs this code. This issue can impact the ability to unlock the driver’s door either with the key fob, keypad, or interior buttons. Prompt diagnosis is important to ensure proper vehicle security and convenience.

Common Symptoms for B1982 #

When the B1982 code is present, you’ll likely notice issues with unlocking the driver’s door, but other related electronic functions may also be affected. Symptoms can range from minor annoyances to complete inability to access the vehicle through the driver’s door. Here are some typical signs:

• Driver’s door does not unlock with the key fob or remote
• Manual unlock switch on the driver’s door is unresponsive
• All other doors unlock normally except the driver’s door
• Intermittent unlocking of the driver’s door
• Warning message on the dashboard (on some models)
• Possible clicking or buzzing noises from inside the driver’s door panel

Likely Causes of B1982 #

The causes behind B1982 can be traced through a logical sequence, starting from the most common to the least frequent. Electrical issues dominate, but mechanical and control module failures are also possible. Here’s the typical order of likelihood:

1. Faulty driver’s door unlock relay (relay contacts worn or stuck)
2. Damaged or corroded wiring in the relay circuit (especially in door harness or connectors)
3. Failed driver’s door lock actuator (motor inside actuator is inoperative or shorted)
4. Faulty Body Control Module (BCM) (rare, but possible if relay and wiring are good)
5. Poor ground or power supply to the relay or actuator circuits

Step-by-Step Diagnosis for B1982 #

Diagnosing a B1982 code requires a methodical approach. Always start with the basics before moving to more advanced checks. Here’s a recommended diagnostic path:

• Verify the code with a professional scan tool and note freeze frame data and any related codes.
• Operate the door locks with the key fob, interior switch, and check for response from other doors.
• Listen for relay clicks or actuator movement in the driver’s door when attempting to unlock.
• Inspect the driver’s door unlock relay for proper operation; swap with a known good relay if possible.
• Check wiring and connectors for corrosion, fraying, or loose pins at the relay, actuator, and BCM.
• Test for voltage and ground at the relay and actuator using a digital multimeter.
• Check the actuator resistance; compare with manufacturer specs.
• If all hardware checks pass, evaluate the BCM output and software integrity (OEM scan tool may be required).

Possible Repairs for B1982 #

The repair for a B1982 code will depend directly on which component is faulty. Always confirm the root cause before replacing parts. Here are the most common solutions matched to typical causes:

• Replace the driver’s door unlock relay if it fails continuity or function tests.
• Repair or replace any corroded, frayed, or damaged wiring/connectors in the relay circuit.
• Replace the driver’s door lock actuator if it is inoperative or shows incorrect resistance.
• Repair poor ground or power supply connections to the relay or actuator.
• Reprogram or replace the BCM only if it is definitively proven to be at fault (rare and often costly).

Is It Safe to Drive with Code B1982? #

Generally, yes, the vehicle remains drivable with code B1982 present. However, you may not be able to unlock or access the driver’s door electronically, which can be a safety and convenience concern—especially in emergencies. If the driver’s door cannot be opened at all, repair should be prioritized. For security reasons, don’t ignore this code for long periods.

Vehicles Most Commonly Affected by B1982 #

This code is found most often on vehicles from manufacturers that use relay-driven door locking systems and detailed body control diagnostics. Ford and its associated brands are the most common, but other OEMs may also use similar systems. Models frequently reporting this code include:

• Ford F-150, F-250, F-350, Ranger
• Ford Explorer, Expedition, Escape
• Ford Fusion, Taurus
• Lincoln Navigator, MKX, Town Car
• Mercury Mountaineer, Sable
• Mazda B-Series (shared platforms)
• Jaguar S-Type, X-Type (certain years)
• Land Rover Freelander (certain years)

Common Mistakes & Best Practices with B1982 #

Mistakes with B1982 often stem from skipping basic checks or replacing parts without proper diagnosis. Here are pitfalls to avoid and tips for success:

• Don’t automatically replace the actuator or BCM—test the relay and wiring first.
• Always inspect connectors for corrosion, especially in climates with high moisture or road salt.
• Use an OEM wiring diagram to trace the circuit and avoid confusion.
• Cycle the lock/unlock function several times during diagnosis to catch intermittent faults.
• Clear codes and retest after repairs to ensure the fix is complete.

Quick FAQ: B1982 #

Here are answers to some common questions owners and techs have about B1982:

• Q: Can a weak battery cause B1982?
  A: While a weak battery can cause low voltage errors in multiple systems, B1982 is typically triggered by a specific fault in the door unlock relay circuit. However, always ensure your battery and charging system are healthy during diagnosis.
• Q: Do I need special tools to fix B1982?
  A: Basic hand tools, a digital multimeter, and a scan tool are sufficient for most repairs. For advanced BCM diagnostics or reprogramming, you may need an OEM-level scan tool.