B1394 — Power Door Memory Lock Relay Circuit Short To Battery #

Note: The description of this code may vary depending on the vehicle manufacturer (OEM). Always refer to your specific vehicle’s service manual for the most accurate information.

• B1394 – Power Door Lock Relay Circuit Short to Battery (Ford, Lincoln, Mercury)
• B1394 – Power Door Memory Lock Relay Circuit High Input (Toyota, Lexus)
• B1394 – Door Lock Memory Relay Circuit Short to Battery (Hyundai, Kia)

Summary of code B1394 #

Diagnostic Trouble Code (DTC) B1394 indicates that the power door memory lock relay circuit has detected a short to battery. This means the circuit is registering a voltage when it should be at ground or open, often pointing to an unintended connection with the battery’s positive terminal. The power door memory lock relay manages the automatic locking/unlocking functions, sometimes with memory presets tied to driver profiles. When this circuit malfunctions, the system may behave unpredictably or fail to operate. Prompt attention is important to prevent further electrical complications or security issues with your vehicle’s doors.

Frequent symptoms for code B1394 #

When the B1394 code is present, you might notice several changes in how your power door locks respond. The car may refuse to lock or unlock consistently, or you could experience erratic behavior such as random locking or unlocking. In some cases, the door lock memory feature—where your car remembers custom lock settings—may become inoperative. Electrical warning lights or messages may appear on the dashboard.

• Power door locks not working or working intermittently
• Doors may lock or unlock at unexpected times
• Loss of memory settings for door locks (if equipped)
• Clicking noises from the door lock relay area
• Warning lights or messages related to the door system

Probable causes for code B1394 #

The most common causes for a B1394 code relate to wiring and relay faults. In most cases, the problem is rooted in the electrical pathway that controls the door lock relay. Below are the main suspects, listed from most to least likely:

1. Shorted wiring in the power door lock circuit (wires contacting battery voltage)
2. Faulty or stuck power door memory lock relay
3. Damaged, corroded, or disconnected wiring connectors
4. Failed door lock actuator (component that physically locks/unlocks the door)
5. Malfunctioning door module or body control module (BCM)
6. Incorrectly installed aftermarket electronics tapping into the door lock circuit

Step-by-step diagnosis for B1394 #

Proper diagnosis of B1394 requires systematic troubleshooting. If you’re comfortable with basic tools and safety procedures, follow these steps. If not, consult a professional technician.

• Confirm the code is active using a professional OBD-II scanner.
• Visually inspect the door lock and memory relay wiring for damage, corrosion, or aftermarket splices.
• Check all connectors related to the relay and actuator for loose pins or corrosion.
• Test the relay itself: Remove it and check resistance across its terminals (compare with OEM specifications).
• With the relay removed, check for battery voltage at the relay socket where it shouldn’t be present (indicating a short).
• Test the door lock actuator, if accessible, for proper operation and shorts.
• If all else checks out, use a wiring diagram to trace the circuit and identify any points where battery voltage could be leaking in.
• As a last resort, test the body control module (BCM) for faults if all wiring and components are healthy.

Possible repairs for code B1394 #

Once the root cause is identified, targeted repairs should resolve the B1394 code. The following are typical fixes, matched to the probable causes above:

• Repair or replace damaged wiring and connectors in the power door lock circuit.
• Replace the faulty power door memory lock relay with a new OEM part.
• Clean and re-seat corroded connectors or terminals.
• Replace the defective door lock actuator if found faulty.
• Remove or rewire any aftermarket devices improperly spliced into the door lock system.
• If verified, replace or reprogram the body control module (BCM).

Can you drive with code B1394? #

Limited—While it’s usually safe to continue driving with code B1394, you may experience unpredictable door locking and security issues. If your doors won’t unlock as expected, it could become a safety concern, especially in emergencies. It’s best to address the issue promptly to avoid getting locked out or compromising your vehicle’s security.

Vehicles most commonly affected by B1394 #

This code appears most frequently on vehicles equipped with advanced power door lock systems and memory features, particularly from these brands:

• Ford (Explorer, Taurus, Expedition, F-Series)
• Lincoln (Navigator, MKZ)
• Toyota (Camry, Avalon, Highlander)
• Lexus (ES, RX, LS)
• Hyundai (Sonata, Santa Fe)
• Kia (Optima, Sorento)

Common mistakes and best practices for B1394 #

Diagnosing and repairing B1394 requires attention to detail. Rushing the process can lead to unnecessary parts replacement or missed root causes. Avoid these pitfalls:

• Replacing the relay without first checking wiring integrity
• Overlooking corroded or loose connectors
• Ignoring aftermarket modifications to the door lock circuit
• Neglecting to clear the code and retest after each repair step
• Failing to use the OEM wiring diagram for tracing faults

Quick FAQ for B1394 #

Got questions about B1394? Here are answers to what vehicle owners and technicians often ask:

• Q: Can a weak battery cause code B1394?
  A: Rarely. B1394 usually points to a wiring or relay fault, not a low battery, but voltage fluctuations can occasionally trigger the code.
• Q: Will my remote key fob stop working if B1394 is set?
  A: It’s possible. If the relay or circuit is shorted, remote lock/unlock functions may become intermittent or disabled.