B1412 – F ABG (1) PS Squib Grounding

The Mitsubishi fault code B1412 – Front Airbag (1) Passenger Squib Ground Short is a manufacturer-specific diagnostic trouble code stored by the SRS (Supplemental Restraint System) airbag ECU on Mitsubishi vehicles. It indicates that the SRS control module has detected one or both conductors of the front passenger airbag squib (pyrotechnic initiator) circuit shorting to vehicle body ground. A ground short on a squib circuit is one of the most serious SRS electrical faults — it creates an uncontrolled current path that bypasses the SRS ECU’s firing control entirely, carrying a genuine risk of accidental airbag deployment. The SRS warning light will be continuously illuminated and the fault must be treated as an immediate priority.

What Does B1412 Mean on a Mitsubishi?

The SRS ECU monitors each squib circuit by supplying a precisely controlled low-level current and measuring the resulting resistance. For the front passenger airbag squib, the expected resistance sits within a narrow calibrated window — typically 2.0–3.0 ohms on Mitsubishi SRS systems. B1412 is stored when the SRS ECU detects that one or both squib conductors in the front passenger airbag (first stage) circuit have developed a path to vehicle ground. This ground short pulls the measured circuit resistance below the minimum threshold and, critically, creates an uncontrolled firing path: if sufficient current were to flow through this ground path, it could trigger the squib and deploy the passenger airbag without any collision event. The designation “(1)” in the fault description refers to the first stage of a dual-stage passenger airbag inflator — the primary firing squib circuit.

Symptoms of B1412

B1412 presents with the following indicators:

• SRS warning light continuously illuminated on the instrument cluster
• B1412 stored in the SRS/airbag ECU when scanned with MUT-III or a compatible scanner
• Front passenger airbag (stage 1) deployment behaviour in a collision cannot be guaranteed — the squib circuit is not under normal SRS ECU control
• Elevated risk of accidental passenger airbag deployment due to the uncontrolled ground current path
• No driveability symptoms — B1412 is a purely electrical SRS fault
• Other SRS functions may remain operational, but the overall system is flagged as degraded
• Potential roadworthiness failure in markets where a permanently illuminated SRS warning light is a testable item at inspection

Common Causes of B1412

• Chafed squib wiring contacting bare metal bodywork — insulation worn through at a routing clip, dashboard bracket edge, or floor aperture allows one squib conductor to contact vehicle ground; the most common wiring cause of B1412
• Pinched harness under the dashboard or passenger footwell trim — squib harness sections routed behind dashboard panels are vulnerable to being pinched against metal during dashboard or HVAC repair work, gradually wearing through insulation
• Corroded SRS connector with conductive contamination between a squib pin and a grounded shell — moisture or conductive debris bridging a squib pin to the earthed outer shell of the yellow SRS connector body
• Internal ground short within the passenger airbag inflator assembly — the squib element or its internal wiring develops a path to the inflator’s grounded metal housing
• Damaged clock spring or rotary connector — if the passenger squib circuit passes through a rotary coupler or intermediate connector near the dashboard that has developed internal damage causing contact with the grounded housing
• Incorrectly routed aftermarket wiring — third-party harness additions in the passenger footwell or dashboard area contacting and damaging the SRS squib harness insulation
• Previous collision damage with residual wiring damage — a prior impact that did not deploy the passenger airbag may have damaged the squib harness routing, leaving conductors in contact with deformed bodywork

Common Misdiagnoses

• Passenger airbag module replaced without tracing the ground short: If the ground short is in the harness rather than the inflator assembly, fitting a new airbag module will not resolve B1412. The ground path must be isolated with a break-out box before any component is replaced.
• Squib circuit tested with a standard multimeter across the squib terminals: Using an unregulated DMM directly across squib terminals is a serious deployment hazard under any squib fault condition — and is acutely dangerous with a ground short present, as the circuit already has an abnormal low-resistance path to ground. Only approved SRS break-out boxes and resistance simulators should be used.
• SRS ECU replaced as a first step: An internal ECU fault is the least probable cause of B1412. Full circuit isolation using a break-out box is mandatory before any module replacement is considered.
• Code cleared without repairing the ground short: B1412 is a current fault actively monitored on every ignition cycle. Clearing the code without repairing the underlying ground path leaves the accidental deployment risk fully intact and the code returns immediately.
• Only the connector inspected without tracing the full harness: A ground short caused by chafed wiring can be located anywhere along the squib harness run between the inflator and the SRS ECU. Connector cleaning alone is insufficient unless the short has been positively isolated to the connector itself using a break-out box.

Affected Mitsubishi Vehicles

Model	Generation	Notes	Years
Outlander PHEV	GG/GF (1st Gen)	Dual-stage passenger airbag; B1412 relates to stage 1 squib circuit	2013–2021
Outlander PHEV	GN (2nd Gen)	Revised SRS architecture; same B1412 definition	2022–present
Outlander (non-PHEV)	GF/GG/ZJ/ZK/ZL	Passenger airbag squib ground short — confirm dual-stage fitment for your market variant	2007–present
Eclipse Cross	GK/GL	Shares SRS module architecture with Outlander range	2017–present
ASX / RVR	GA/XD	Dashboard harness routing vulnerable on higher-mileage and previously repaired examples	2010–present
Galant Fortis / Lancer	CY/CZ	Market-specific SRS configurations — verify stage designation before diagnosing	2007–2017

Tools & Equipment Required

Tool	Purpose	Notes
Mitsubishi MUT-III / MUT-IV	SRS scan, live data, code clear	Required to confirm B1412 and verify repair
SRS break-out box / squib resistance simulator	Safe squib circuit resistance measurement and ground short isolation	Never use a standard DMM directly across squib terminals
Digital multimeter (DMM)	Insulation resistance testing between squib conductors and body ground	Only with all SRS connectors disconnected and shorting bars confirmed engaged
Wiring diagram (OEM)	Identify full squib circuit routing from passenger airbag inflator to SRS ECU	Mitchell1 DIY or Mitsubishi FAST-II
Electrical contact cleaner & dielectric grease	SRS connector cleaning and pin isolation	Inspect each pin cavity individually for contact with grounded connector shell
Dashboard and trim removal tools	Access to passenger airbag module and squib harness routing	Plastic pry tools; Torx and hex set for airbag module fasteners

Step-by-Step Diagnosis

• 1
  Disable the SRS System Immediately — Before Any WorkSwitch off the ignition, remove the SRS fuse, and disconnect the battery negative terminal. Wait a minimum of 60 seconds before approaching any SRS component, connector, or wiring. A ground short on a passenger airbag squib circuit carries a genuine accidental deployment risk — the SRS disable procedure and capacitor discharge wait are non-negotiable before any diagnostic step.
• 2
  Confirm B1412 with a Full SRS ScanReconnect power and use MUT-III or equivalent to read all stored SRS fault codes. Confirm B1412 is current. Note any additional SRS codes — particularly any codes affecting adjacent squib circuits — that may indicate a shared harness damage point or a prior collision event that has disturbed the SRS wiring architecture.
• 3
  Check for Prior Collision or Dashboard Repair EvidenceInspect the passenger side dashboard, airbag cover, and footwell area for signs of previous collision damage, airbag deployment, or repair work. An undeployed airbag with a squib ground short requires electrical diagnosis. A previously deployed or disturbed airbag module may have left damaged wiring in contact with bodywork.
• 4
  Inspect the SRS Connector at the Passenger Airbag ModuleWith SRS disabled, locate the yellow SRS connector at the passenger airbag module in the dashboard. Disconnect carefully and inspect the connector body under good lighting — look specifically for conductive deposits, moisture residue, or corrosion bridging a squib pin to the grounded outer shell of the connector housing. Inspect each pin cavity individually.
• 5
  Isolate the Ground Short Using a Break-Out BoxConnect an approved SRS break-out box at the SRS ECU harness connector. Measure resistance between the stage 1 passenger squib circuit conductors and vehicle body ground. A low resistance reading to ground confirms the fault is present. Disconnect the passenger airbag module connector and re-measure — if the ground short clears, the short is within the inflator assembly or its connector. If the ground short remains with the module disconnected, the fault is in the wiring harness between the module and the SRS ECU.
• 6
  Trace the Squib Harness for Insulation DamageIf the ground short is in the harness, route out the stage 1 squib harness from the passenger airbag module connector back to the SRS ECU, systematically checking all sections for insulation damage against dashboard metalwork, bracket edges, routing clip contact points, and any areas where aftermarket wiring has been installed nearby. Use a DMM in insulation resistance mode — with all SRS connectors fully disconnected and shorting bars engaged — to identify which conductor is grounding and at which harness segment.

Scanner Readout Explained

====================================================
  MITSUBISHI MUT-III SE — DIAGNOSTIC REPORT
====================================================
  Vehicle:     2019 Outlander PHEV (GG3W)
  Date:        2025-03-27  08:52:17
====================================================
MODULE: SRS / AIRBAG ECU
----------------------------------------------------
  B1412  Front Airbag (1) Passenger Squib — Ground Short
         Status:       Confirmed / Current
         Freeze Frame:
           Squib Circuit Resistance to Ground:  0.4 Ω (ground short detected)
           Expected Resistance to Ground:       >1 MΩ (fully isolated)
           Expected Squib Loop Resistance:      2.0–3.0 Ω
           SRS Warning Lamp:                   ON
====================================================
  LIVE DATA (SRS System Status)
====================================================
  Driver Front Airbag Squib (1):          OK
  Passenger Front Airbag Squib (1):       GROUND SHORT — FAULT ACTIVE
  Passenger Front Airbag Squib (2):       OK
  Driver Seatbelt Pretensioner Squib:     OK
  Passenger Pretensioner Squib:           OK
  Side Curtain L Squib:                   OK
  Side Curtain R Squib:                   OK
====================================================
  NOTE: SRS system flagged as degraded.
  Passenger airbag stage 1 deployment
  not under normal SRS ECU control.
  Accidental deployment risk elevated.
====================================================

Step-by-Step Repair Guide

Repair Path A: Passenger Airbag Module Replacement

• 1
  Disable the SRS SystemRemove the SRS fuse and disconnect the battery negative terminal. Wait a minimum of 60 seconds. With a ground short fault active, treat the passenger airbag module as a live and unstable pyrotechnic device until the system is fully de-energised and the capacitor discharge period has elapsed without exception.
• 2
  Remove the Passenger Dashboard Trim and Airbag CoverUsing plastic trim tools, carefully remove the passenger side dashboard trim and airbag cover assembly. Refer to the OEM workshop manual for the specific trim removal sequence, airbag cover fastener locations, and any retention clip positions for your model year — procedures vary between generations.
• 3
  Disconnect the Squib Connector at the Airbag ModuleLocate the yellow SRS connector(s) at the passenger airbag module. Press the secondary lock release and disconnect carefully. The integrated shorting bar engages on disconnection, shorting the squib terminals and eliminating any residual current path through the squib during the repair.
• 4
  Remove and Safely Dispose of the Faulty ModuleUnbolt the passenger airbag module from its mounting bracket. Handle the module face-up on a stable, flat surface — even an undeployed module with an internal squib fault is a live pyrotechnic device. Follow local regulations for disposal of pyrotechnic automotive components. Do not disassemble the module under any circumstances.
• 5
  Fit the OEM Replacement ModuleInstall the new OEM passenger airbag module onto the mounting bracket and torque all fasteners to the workshop manual specification. Reconnect the yellow SRS connector(s) firmly — the secondary lock must click fully and positively into place on each connector before any trim is refitted.
• 6
  Re-enable SRS, Clear the Code & VerifyRefit the airbag cover and all dashboard trim. Reconnect the battery and refit the SRS fuse. Use MUT-III to clear B1412 and run a full SRS system check. Confirm the SRS warning light extinguishes and that no further SRS codes are stored.

Repair Path B: SRS Harness Ground Short Repair

• 1
  Isolate the Ground Short Location in the HarnessWith SRS disabled and using an approved break-out box, confirm the ground short is present in the harness with the airbag module disconnected. Segment-test the squib harness using a DMM in insulation resistance mode — with all SRS connectors disconnected — to identify which conductor is grounding and to narrow the fault to a specific harness section between the airbag module and the SRS ECU.
• 2
  Locate and Repair the Damaged InsulationTrace the harness in the identified segment. Common ground short damage points are where the squib harness contacts a dashboard bracket edge, a routing clip has worn through insulation, or where aftermarket wiring has been routed alongside and pressed against the SRS harness. Repair using an OEM-specification SRS harness repair kit — confirm with the workshop manual whether splice repairs are permitted on this specific squib circuit before proceeding.
• 3
  Verify Insulation, Re-enable SRS & ClearBefore refitting any trim, confirm that squib circuit resistance to body ground is greater than 1 MΩ and that squib loop resistance is within the 2.0–3.0 Ω specification, using the break-out box. Reconnect the battery and SRS fuse, clear B1412 with MUT-III, and confirm the SRS warning light extinguishes with no returning codes.

Repair Path C: SRS Connector Cleaning for Ground Bridging

• 1
  Disable SRS & Access the Airbag Module ConnectorFollow the full SRS disable procedure. Access the passenger airbag module connector. Disconnect and inspect the connector body under strong lighting — look specifically for conductive corrosion deposits or moisture bridging between a squib pin cavity and the grounded metal outer shell of the yellow SRS connector housing.
• 2
  Clean Each Pin Cavity IndividuallyApply electrical contact cleaner to each pin cavity individually, ensuring any conductive bridging deposit between the pin and the grounded connector shell is fully cleared. Allow to dry completely. Verify with a break-out box that pin-to-ground resistance is above 1 MΩ before reconnecting.
• 3
  Apply Dielectric Grease, Reseat & ClearApply dielectric grease to each pin face to prevent future moisture ingress. Reconnect the SRS connector firmly — the secondary lock must click fully into position. Re-enable the SRS system, clear B1412 with MUT-III, and confirm the warning light extinguishes with no returning codes.

Repair Cost Estimates

Repair	Parts Cost (est.)	Labour (est.)	Total (est.)	DIY Difficulty
SRS connector cleaning — ground bridging	€0–€10	0.5–1 hr	€0–€90	Medium — SRS safety protocols essential
SRS harness ground short repair	€10–€60	1–4 hr	€60–€360	Hard — requires SRS break-out box and dashboard access
Passenger airbag module replacement (OEM)	€200–€600	1–3 hr	€260–€780	Hard — SRS specialist strongly recommended
SRS ECU connector pin repair	€5–€30	1–2 hr	€55–€200	Hard — requires SRS break-out box

Prevention & Maintenance Tips

• Always disable the SRS system before any dashboard, HVAC, or glove box repair work — the passenger airbag squib harness runs throughout the dashboard space and is easily disturbed or pinched during unrelated repairs
• Inspect squib harness routing clips and bracket clearances during every dashboard access — a clip that has partially released allows the harness to contact bare metal and develop a ground short gradually over time
• Never route aftermarket wiring alongside the SRS squib harness in the dashboard or footwell — contact between aftermarket cabling and the squib harness is a preventable cause of insulation damage leading to ground shorts
• Protect SRS connectors from moisture ingress — apply fresh dielectric grease to yellow SRS connector pin faces during any scheduled SRS inspection to prevent conductive corrosion bridging to the grounded connector shell
• Use OEM or OEM-equivalent airbag modules only — non-standard modules may present squib resistance values outside the SRS ECU calibration window and may generate a new fault immediately after installation
• Treat a ground short SRS warning light as more urgent than an open circuit warning — the accidental deployment risk associated with B1412 is higher than most other SRS fault types and should not be deferred

Frequently Asked Questions

Can I drive my Mitsubishi with B1412 stored?

The vehicle remains mechanically driveable, but a ground short on the passenger airbag squib circuit carries a genuine risk of accidental airbag deployment while driving — a deployed passenger airbag at speed poses serious injury risk to the front passenger. B1412 should be treated as an immediate priority repair rather than a fault to monitor and defer.

Why is a ground short more dangerous than an open circuit on a squib?

An open circuit simply means the airbag cannot deploy — the circuit is broken and no current can flow. A ground short creates an uncontrolled low-resistance path from the squib circuit to vehicle ground that exists independently of the SRS ECU’s firing control. If sufficient current flows through that ground path — from a voltage spike, a secondary electrical fault, or another system’s switching event — it could trigger the squib without any collision event or SRS ECU command.

Can I use my multimeter to find where the harness is grounding?

A standard DMM may be used in insulation resistance mode on individual harness conductors only after all SRS connectors are fully disconnected and the shorting bars on every yellow SRS connector are confirmed engaged. Under these conditions there is no squib in circuit and no deployment risk from the DMM’s test current. Never use a DMM or test light directly across the squib terminals or at any point in the circuit while any SRS connector remains connected.

What does the “(1)” designation in B1412 mean?

The “(1)” refers to the first stage squib of a dual-stage passenger airbag inflator. Dual-stage airbags use two independently fired squib circuits to control deployment force — stage 1 fires in lower-severity impacts, stage 2 supplements stage 1 in higher-severity events. B1412 is specific to the stage 1 circuit. A separate code would be stored for a fault on the stage 2 squib circuit.

Will B1412 clear itself if the ground path is intermittent?

No. B1412 is stored in SRS ECU memory and must be actively cleared with MUT-III or a compatible scanner. If the ground short is intermittent — caused by a harness that only contacts bodywork at certain dashboard temperatures or vibration conditions — the code may not reappear immediately after clearing, but the underlying insulation damage and accidental deployment risk remain. An intermittent ground short requires the same thorough harness tracing and repair as a permanent one.

Could previous dashboard repair work have caused B1412?

Yes — this is a common real-world trigger. HVAC repairs, instrument cluster replacements, infotainment upgrades, and glove box work all require partial dashboard disassembly in the area where the passenger airbag squib harness is routed. If the harness was pinched against a bracket during reassembly, or a routing clip was omitted, the insulation will wear through against bare metal over subsequent heat cycles and vibration, eventually producing B1412.

Does the SRS ECU need replacing if B1412 returns after a new airbag module and harness repair?

Only after full circuit verification has confirmed that squib circuit resistance to body ground exceeds 1 MΩ and squib loop resistance is within the 2.0–3.0 Ω specification from the airbag module connector all the way to the SRS ECU connector pins, with no ground path detected anywhere in the circuit. An internal ECU output stage fault is the least probable cause of B1412 but cannot be excluded if all wiring, connectors, and the airbag module have been confirmed fault-free.

Conclusion

Mitsubishi B1412 – Front Airbag (1) Passenger Squib Ground Short is one of the most urgent SRS fault types due to the accidental deployment risk created by the uncontrolled ground current path on the passenger airbag squib circuit. The most common causes are insulation damage in the squib harness from chafing against dashboard metalwork, conductive contamination bridging a squib pin to the grounded SRS connector shell, or an internal ground short within the airbag inflator assembly. Always follow the full SRS disable procedure and observe the 60-second wait, use an approved break-out box to isolate whether the ground short is in the module, the connector, or the harness, replace faulty components with OEM parts only, and clear and verify with MUT-III.