B1404 on 2020-2022 Lincoln Aviator: Airbag Light Causes and Fixes

What's Unique About the 2020-2022 Lincoln AVIATOR

The 2020-2022 Lincoln Aviator, along with its Ford Explorer and Bronco platform mates, is known to have a specific weakness in the wiring connection for the side airbags. Ford has acknowledged in TSB 22-2190 that 'contamination and relative movement' in the connector between the seat wiring harness and the side airbag can cause an open circuit, triggering the B1404 code. This is not a random wiring failure; it's a documented pattern addressed by a specific manufacturer TSB.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• Illuminated airbag warning light on the dashboard.

Most Likely Causes

1. Faulty Side Airbag Wiring Connector 🔴 High Probability This is a known issue documented in Lincoln TSB 22-2190. Contamination and relative movement in the connector (C367 for the left side) cause a poor connection or a broken wire at the connector pin. This is a common failure point across many Ford products.
   How to confirm: A technician will confirm the B1404:13 code is present and inspect the yellow connector between the wiring harness and the side airbag, located under the front seat. Visual inspection often reveals a broken wire, typically purple or black, right at the connector.
   Typical fix: The official fix per TSB 22-2190 involves replacing the faulty connector with a service pigtail (Part No. BU2Z-14S411-BMA, which is superseded by BU2Z-14S411-BMB) and also replacing the entire side airbag module as a unit. Some owners have successfully repaired the broken wire by soldering, which is preferred over crimping for airbag circuits to maintain correct resistance.
   Est. part cost: $25-$50 for the pigtail, $200-$400 for the airbag module.
2. Damaged Wiring Harness ⚪ Low Probability Wires under the seat can be damaged by items stored there or by the seat's movement. On some other Lincoln models, harness routing has led to recalls for pinched wires.
   How to confirm: Visually inspect the wiring harness under the driver's seat for any signs of pinching, chafing, or broken wires away from the connector itself.
   Typical fix: Repair the damaged section of wire. For airbag circuits, soldering is strongly recommended over crimp connectors to ensure proper resistance and avoid future issues.
   Est. part cost: $5-$20 for wiring repair supplies.
3. Faulty Side Airbag Module ⚪ Low Probability While the TSB procedure replaces the airbag, the root cause is typically the connector. The airbag itself failing is less common but possible. The TSB requires replacement likely as a precaution to ensure the entire circuit is new and reliable.
   How to confirm: If replacing the connector pigtail does not resolve the code, the airbag module itself is the next likely culprit. This is diagnosed through substitution.
   Typical fix: Replace the driver's side airbag module (Part No. LB5Z-78611D11-B).
   Est. part cost: $200-$400

Rare But Worth Checking

• Faulty Restraints Control Module (RCM): This is the central computer for the airbag system, located under the center console. It's rarely the cause of a single-circuit fault code and should only be considered after all other possibilities (wiring, connectors, sensor) have been eliminated.

Diagnosis Steps

1. Confirm the presence of code B1404, specifically with the failure type ':13', using a diagnostic scan tool that can read SRS codes (like FORScan).
2. Gain access to the wiring under the driver's seat. Per the TSB, the seat does not need to be removed.
3. Locate and disconnect the side airbag connector (C367), which is typically a yellow connector to signify it is part of the SRS system.
4. Carefully inspect the connector terminals on both the harness side and the airbag side for contamination, corrosion, or spread pins. Pay close attention to the wires entering the connector for breaks, especially the purple or black wire.
5. If the vehicle falls under TSB 22-2190, follow the service procedure to replace the connector with the specified pigtail and replace the side airbag module.
6. If the TSB is not being followed, test for continuity and resistance through the driver's side airbag circuit. An open circuit (infinite resistance or resistance over 10,000 ohms) will confirm the code. Be extremely cautious not to probe the airbag side of the circuit with a standard multimeter, as this could cause deployment.
7. After repairs are complete, clear the DTCs from the RCM and cycle the ignition. Monitor the airbag light to ensure it performs its self-check and stays off.

Parts You'll Likely Need

• Side Airbag Connector Service Pigtail (OEM #BU2Z-14S411-BMA) — This is the specific part Lincoln identified to fix the poor connection that causes code B1404:13. This part has been superseded.
  Trusted brands: Motorcraft
  OEM price range: $25-$50
  Aftermarket price range: $15-$30
• Left Side Airbag Module (OEM #LB5Z-78611D11-B) — The official TSB repair procedure requires replacing the side airbag module along with the connector pigtail to ensure a complete and lasting repair.
  Trusted brands: Motorcraft
  OEM price range: $200-$400
  Aftermarket price range: Not Recommended

Related Codes That Often Appear With This One

• B1407:13 — This code is for the passenger side airbag ('Passenger Side Airbag Deployment Control: Circuit Open'). The same connector issue that causes B1404 on the driver's side can happen on the passenger side, and TSB 22-2190 addresses both codes simultaneously.

Technical Service Bulletins (TSBs) & Recalls

• TSB 22-2190: Supersedes a previous version and outlines the issue and repair procedure, which involves replacing the side airbag connector with a pigtail and replacing the airbag module itself. This TSB also applies to the 2020-2022 Ford Explorer and 2021-2022 Ford Bronco.
• TSB 21-2297: The earlier version of the bulletin for the same issue, now superseded by 22-2190.

Platform-Specific Known Issues

• A recall (20S48 / NHTSA 20V-497) was issued for some 2020 Aviator models for improperly tightened side airbag and seat back module attachments, which could affect deployment. While different from the TSB's wiring issue, it highlights the sensitivity of the side airbag system in these vehicles.
• TSB 22-2190 explicitly states that for 2020-2022 Aviators, an illuminated airbag light with DTC B1404:13 is likely due to 'contamination and relative movement in the connection between the wiring harness and the side airbag.'

Mechanic-Grade Diagnostic Values

• Driver Side Airbag Deployment Loop Resistance — expected: 1.44 to 3.52 ohms. Failure: A reading greater than 3.52 ohms can trigger a B1404:13 (Circuit Open) DTC. A reading over 10,000 ohms is considered a hard open circuit.

Hidden / Shadow Codes Worth Checking

• B1404:13-0A: The ':13' is the Failure Type Byte (FTB) indicating 'Circuit Open'. The '-0A' is a status byte that can indicate details about the fault's occurrence, such as being a previously set DTC but not present at the time of request. (see via A scan tool like FORScan or the dealer-level Ford IDS can display the full DTC with its failure type and status bytes.)

Scan Tool Commands That Help

• FORScan: RCM Self-Test — After a repair, this command initiates a self-test of the Restraints Control Module to confirm the fault is cleared and the system is functioning correctly.
• FORScan / Ford IDS: RCM Module Programming / As-Built Configuration — This is required if the Restraints Control Module (RCM) itself is replaced. The new module must be programmed with the vehicle's specific configuration data (As-Built data) to function correctly.

Wiring & Ground Locations

• C367 — Under the driver's front seat, connecting the body harness to the seat harness for the side airbag.. This is the primary failure point identified in TSB 22-2190 for the B1404:13 code due to contamination and wire strain from seat movement.
• Restraints Control Module (RCM) — Under the center console, between the front seats. Access typically requires removing side panels from the console, and in some cases, the passenger seat.. This is the module that sets the DTC. All wiring for the airbag circuits originates from this module.
• AWD Module Ground — Under the driver's seat, mounted to the floor.. While not directly part of the SRS circuit, a poor ground at the nearby AWD module on these platforms is a known issue that can cause various electrical problems. While unlikely to cause B1404 specifically, it highlights the sensitivity of vehicle electronics in this physical area to grounding issues.

Real Owner Repair Stories

• Bronco6G Forum User (2021 Ford Bronco) — Airbag warning light came on.
  ❌ Tried (didn't work) Clearing the code (it returned immediately)., Replacing an initial part suggested by the dealer.
  ✅ What actually fixed it The dealer identified a fault in the wiring harness leading to the part they had just replaced. Replacing the harness resolved the airbag light issue.
• YouTube video by 'The repair man' (2017 Ford F-150) — Airbag light with code B1404-13.
  ❌ Tried (didn't work) Initial visual inspection of the connector exterior.
  ✅ What actually fixed it Upon closer inspection of the yellow connector under the driver's seat, the user found a completely broken purple wire. He soldered the wire back together, applied heat shrink, and the code was resolved.

OEM Part Supersession History

• BU2Z-14S411-BMA → BU2Z-14S411-BMB — Standard part revision by the manufacturer. The new part serves the same function.
  Heads up: The original part number may also be listed as WPT-1228, while the new part number may be listed as WPT-1680. They are interchangeable for this repair.