B1920

Code

Other B — Body

Air Bag Passenger Circuit Failure

Brand: Other

Type: B — Body

Views: UK: 23 EN: 38 RU: 21

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Open circuit in passenger airbag wiring
Short to ground or short to voltage in passenger airbag circuit
Poor or corroded connector or pin at passenger airbag or seat module
Faulty passenger airbag squib (inflator)
Faulty occupant classification/seat weight sensor or harness
SRS control module internal fault or lost communication

Symptoms

SRS (airbag) warning lamp illuminated on instrument cluster
Possible supplemental restraint system message on dash
Passenger airbag “OFF/ON” indicator may be incorrect or disabled
Possible diagnostic trouble codes present for occupant classification or communication
Vehicle may log other SRS-related codes after clearing

What to check

Scan SRS module and read all related codes and freeze-frame data
Visually inspect passenger airbag module, under-seat connectors, occupant sensor, harness routing, and associated connectors for damage, corrosion, loosening, or aftermarket modifications
Verify SRS warning lamp behavior and any passenger airbag status indicator
Check for additional network/communication DTCs (CAN/U codes) that might affect SRS
Follow manufacturer safety procedure before probing SRS circuits (battery disconnect and specified wait time)

Signal parameters

Passenger airbag squib resistance (typical): about 1–3 ohms for many systems — consult manufacturer spec
Open-circuit: infinite/OL on ohmmeter between squib pins
Short to ground: near 0 ohms between squib circuit and chassis ground
SRS ECU power supply: approx. battery voltage (11–14 V) at fuse/ECU feed when key on
Occupant classification sensor: low-voltage signal typically 0–5 V (manufacturer-specific)
CAN/Circuit messages: SRS ECU should be present on network; lost communication flagged in many systems

Diagnostic algorithm

Safety first: follow manufacturer procedure — disable ignition, disconnect negative battery terminal and wait the specified time for capacitors to discharge before accessing SRS components
Use an OEM-capable scan tool to read and record all SRS/airbag codes and freeze-frame data; note any related modules reporting faults
Visually inspect passenger airbag module, under-dash harness, under-seat harness and connectors, seat tracks, and occupant classification components for physical damage, corrosion, or signs of water intrusion
With battery disconnected and following safety wait, disconnect the passenger airbag connector and inspect pins for corrosion, bent pins, or heat damage
Measure squib resistance at the airbag module connector with an ohmmeter (consult manufacturer spec). If resistance is within spec, check continuity to SRS ECU; if open or out of range, locate break/splice
Check for short to ground/voltage: with power removed, measure resistance from squib circuit to chassis ground; with power on (careful, follow safety guidance), check for unintended voltage on squib circuit only as allowed by manufacturer procedures
Inspect and test occupant classification sensor (seat mat) connectors and sensor outputs per manufacturer procedure — check for proper supply voltage, ground, and signal voltage
Verify SRS ECU power and ground voltages at fuse/ECU connectors with key ON (observe safety precautions). Check for blown fuses or relays in SRS feed circuits
If wiring and connectors check good, compare module wiring diagram and consider swapping or bench-testing suspect components only per OEM guidance; replace suspected faulty module or squib assemblies as required
After repairs, clear codes, reconnect battery, and perform SRS self-test with scan tool; verify lamp extinguishes and passenger airbag status is correct
If problem persists or diagnostics require manufacturer-level service data, consult factory wiring diagrams and repair information or escalate to dealer-level SRS technician

Likely causes

Broken/chafed wire under or behind passenger seat (seat track movement)
Loose/unseated connector at passenger airbag module or under-seat junction connector
Water intrusion or corrosion in connector(s) under the seat or in dash
Failed passenger airbag squib with abnormal resistance (low/high)
Faulty occupant classification mat producing out-of-range voltage or open circuit
Previous crash repair left an improper splice or connector

Fault status

⚠️ Status

Air Bag Passenger Circuit Failure — SRS detected abnormal passenger airbag circuit condition. SRS warning lamp will be ON; passenger airbag may be disabled until fault is corrected.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-2.5 hours