B1906

Code

Other B — Body

Air Bag Crash Sensor #2 Feed/Return Circuit Short To Ground

Brand: Other

Type: B — Body

Views: UK: 17 EN: 37 RU: 50

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Chafed, pinched, or damaged wiring in the sensor harness contacting chassis ground
Corroded, bent, or pushed-out connector pins causing a short to ground
Water intrusion or contamination in sensor connector or harness
Faulty/cracked crash sensor #2 with internal short
Faulty air bag (SRS) control module with internal circuit fault
Poor or incorrect previous repair or aftermarket accessory damaged wiring

Symptoms

SRS/Airbag warning lamp illuminated on dash
Stored B1906 (and possibly other SRS-related) trouble codes
Possible disabling of airbag deployment circuits until repaired
Vehicle may show other SRS-related warnings or refusals on scan tool

What to check

Use a scan tool to read and record all SRS codes and freeze-frame data
Follow manufacturer procedure to disable SRS power (disconnect battery and wait recommended interval) before probing SRS connectors
Visually inspect wiring and connectors from crash sensor #2 to the SRS control module for damage, kinks, chafing, corrosion, or water entry
Inspect sensor #2 mounting and surrounding area for harness contact points or pinched wiring
Unplug the sensor connector and inspect pins for corrosion, bent pins, or foreign material
With the connector disconnected, measure continuity between feed/return circuit pins and chassis ground to check for a short

Signal parameters

Reference/feed voltage (typical): ~5 V (verify exact value in factory service information) when ignition is ON
Signal/return behavior: normally not shorted to ground; after a short to ground the pin voltage will read near 0 V
Continuity: a healthy feed/return circuit should not have direct continuity to chassis ground (open or very high resistance)
Short indication: continuity to ground with very low resistance (near 0 Ω) indicates a short to ground
Always verify actual voltages/resistances against vehicle manufacturer service data

Diagnostic algorithm

Read and record all SRS codes and any related data with a compliant scan tool.
Disable SRS power using the manufacturer-recommended procedure (battery disconnect and waiting time) before touching connectors or airbags.
Visually inspect the crash sensor #2, its connector, and the harness route to the control module for damage, rubbing points, or water contamination; repair obvious damage.
Disconnect the sensor #2 connector. With ignition ON (and safety precautions in place) measure voltage at the feed pin; verify reference voltage per factory spec. If the feed is shorted to ground at the harness side, voltage will be near 0 V.
With harness disconnected from both ends (sensor and module where possible), use an ohmmeter to check continuity between the feed/return circuit and chassis ground. Low resistance indicates a short to ground in the harness or a shorted sensor if only connected at sensor end.
If short is present only when the sensor is connected, replace the sensor and retest.
If short is present with sensor removed, trace wiring back toward the SRS control module in sections, disconnecting connectors and testing each section until the shorted section is isolated. Repair or replace damaged wiring or connectors.
If wiring checks good and short remains, suspect SRS control module internal fault—verify using manufacturer procedures and replace module only after confirming harness and sensors are good.
After repairs, clear codes, perform SRS system self-tests with a scan tool, and confirm codes do not return. Reconnect battery and verify SRS lamp behavior.