Code
B1492
MITSUBISHI
B — Body
F ABG(2)PS squib grounding
Views:
UK: 4
EN: 12
RU: 5
AI status
Completed
Completed
100%
Causes
- Damaged or shorted wiring in the squib ground circuit
- Corroded, loose or bent squib connector pins (passenger-side)
- Poor chassis or module ground connection
- Faulty squib (airbag inflator/pretensioner) with internal short
- Faulty SRS control module or internal monitoring circuit
- Aftermarket seats, repairs, or previous incorrect airbag service
Symptoms
- SRS / airbag warning light illuminated on instrument panel
- Possible disabling of passenger airbag or pretensioner function
- Diagnostic trouble codes stored in SRS module (including B1492)
- Vehicle may fail safety inspection where SRS faults are tested
What to check
- Read all SRS codes with a diagnostic scanner capable of manufacturer airbag functions; record freeze frame/store data.
- Visual inspection of passenger-side seat, connectors, and wiring harness routing for damage, chafing, or corrosion.
- Inspect and confirm tight, clean chassis and module ground points.
- Measure squib circuit resistance at the squib connector and at SRS module connector (with battery disconnected as required).
- Wiggle test harness/connectors while monitoring fault presence (with safe procedures).
- Compare results to vehicle-specific service manual values and wiring diagram.
Signal parameters
- Normal squib resistance (typical): low ohms (commonly ~2–5 Ω for many inflators) — consult vehicle data.
- Open-circuit: very high resistance or OL indicates broken/open wiring or disconnected connector.
- Short-to-ground: measured near 0 Ω between squib positive and chassis ground or squib negative and chassis ground.
- ECU fault threshold: SRS module monitors continuity and flags fault when resistance is outside expected range or when short/open is detected (vehicle-specific).
- Battery voltage should be stable (12 V) during tests; do not power-crank or attempt firing tests.
Diagnostic algorithm
- Safety first: follow manufacturer SRS safety procedures. Disable battery negative terminal and wait prescribed time (service manual) before touching squib connectors. Wear antistatic precautions and do not work near the passenger with connectors attached.
- Use a capable scan tool to read/record all SRS codes and freeze-frame data. Clear codes only after repairs and verify reappearance.
- Perform a careful visual inspection of the passenger seat area, wiring harness under the seat, connectors under the seat and at the B-pillar, and the SRS control module area for damage, corrosion, or disconnected plugs.
- With battery service procedure observed, measure DC resistance of the passenger squib at the connector and compare to spec. A very low resistance (~0 Ω) suggests a short to ground; very high or OL suggests open circuit.
- Check continuity between the squib ground conductor and chassis ground. Also check continuity between squib return and SRS module connector ground pin. Repair any shorts or opens found.
- Inspect and clean connector pins; repair/replace any corroded or damaged terminals. Re-pin connector if necessary using proper crimp terminals.
- If wiring and connectors check OK, swap or bench-test squib only if safe and per service manual (many squibs cannot be safely bench-tested). Prefer replacing suspect squib with known-good/unused part following safety rules.
- If wiring and squib are OK, investigate SRS control module grounding and internal faults. Refer to wiring diagrams and test module outputs/inputs per service manual.
- After repair, reconnect battery per procedure, clear codes with scanner, and perform SRS system self-test. Verify the SRS warning light goes out and no B1492 returns.
- If fault persists after reasonable checks/repairs, consult manufacturer technical service information or replace the SRS control module only after confirming upstream wiring and squib conditions.
Likely causes
- Connector corrosion or bent terminal at passenger squib connector
- Chafed wiring contacting chassis (short to ground) under seat or in harness
- Open or intermittent wire/terminal causing erroneous ground detection
- Failed squib with internal short to ground
- Poor ground point near SRS control module or seat anchor ground
Fault status
Status
SRS control module detected grounding fault in passenger squib circuit (B1492). Check passenger squib wiring, connectors, ground points and squib unit; SRS system may be disabled until repaired.
Repair difficulty: Hard
Diagnostic time: 1.0-3.0 hours
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