B1312: Passenger seat occupant sensing fault, occupancy mat or module (Suzuki)

Passenger seat sensor / occupancy mat fault, airbag light on

Severity: Inspect soon

A fault in the passenger occupant sensing leaves the airbag light on, and the owner complaints show an unresolved fault. Honda's and Toyota's owner's manuals say a lit airbag light needs prompt attention because the airbags or belt tensioners may not work as designed.

Safety-critical system: explanation only, no DIY steps. Source: how we rate severity

B1312 in short

On Suzuki, B1312 means the airbag computer found a fault in the front passenger seat occupant sensing, the occupancy mat and its module. The airbag light stays on and the passenger airbag may not deploy. Dealers in complaints replaced the seat cushion or mat. Have it checked soon; the repair can be costly.

The passenger seat has a sensing mat and a small module that tell the airbag computer whether and who is sitting there. B1312 is stored when that system reads a fault, and the airbag light stays on.

Suzuki has a service bulletin for B1312 and an airbag light that stays on. Owners of SX4s report dealers finding an open circuit in the occupant classification module and replacing the passenger seat cushion or mat.

Owners also report that the part is costly and that some cars were out of warranty, so ask the dealer about coverage.

Pick your make

B1312 is a manufacturer-specific code: its meaning depends on who built the car.

Other makes: meaning not verified. Check with a scan tool that reads manufacturer definitions.

B1312 on Suzuki

Most likely causes

Cause 1: Passenger seat occupancy mat or module (seat cushion assembly)
Supported by vehicle data
Why it ranks here
Dealer readouts quoted in three SX4 complaints name the passenger seat sensor, mat or module and replaced the seat cushion assembly.
What would change this
Rises if no other airbag codes are set. Falls if the connectors under the seat are found damaged or loose.

What to test first

Start at step 1. Each result tells you what it means and where to go next.

Step 1: Have the airbag codes read with a scan tool that can talk to the airbag module, and note every code stored.
Low riskTool: scan tool with airbag (SRS) access
- IfB1312 is stored on a Suzuki
  It meansThe passenger occupant sensing system reads a fault.
  Go to step 2
- IfOther airbag codes are stored as well
  It meansA technician should work through them in the order the service manual gives.
  Go to step 3
Step 2: Give your VIN to the dealer and ask whether a service bulletin or warranty extension covers this code on your car.
Low risk
- IfA bulletin or extension applies
  It meansThe dealer repairs it under the bulletin.
  Go to step 3
- IfNothing applies
  It meansThe circuit still needs a diagnosis.
  Go to step 3
Step 3: Leave the diagnosis to a dealer or trained technician, who measures the circuit with the service manual procedure.
Best left to a shopTool: scan tool with airbag access, manufacturer procedure
Warning:Airbag wiring can set off an airbag if it is probed, disconnected or powered the wrong way, and that can cause serious injury. Do not test or unplug airbag connectors yourself.
- IfThe mat or module reads open or invalid
  It meansThe seat cushion assembly is replaced.
  Points to: Passenger seat occupancy mat or module (seat cushion assembly)

Symptoms

Airbag (SRS) warning light stays on after the engine starts
Passenger airbag status indicator shows off with someone seated

How to fix

This is a safety-critical system, so we explain the code but don't give repair steps. Have it inspected by a qualified technician.

Parts and cost context

Passenger seat occupancy mat / seat cushion assembly:Owners quote the part as expensive; some dealers covered it. Ask about coverage first. Dealer work. Labour varies; get a quote.

Labor varies by vehicle and shop; get a quote before you approve a repair.

Compare used part prices on PartPriceGuide

On your vehicle

Suzuki

2007–2008 · SX4
Supported by vehicle data
Several complaints quote dealers finding B1312 and replacing the passenger seat cushion or mat.

No curated relationships for B1312 yet.

All Airbags and seat-belt restraints (SRS) codes

Sources and review

2023 Accord Owner's Manual: Airbag System Indicators — American Honda Motor Co.
Camry Owner's Manual (OM06291U) — Toyota
Suzuki SB-B1312: air bag warning light stays on when DTC B1312 is stored — Suzuki Motor USA
NHTSA complaint ODI 893332 (2008 Suzuki SX4) — NHTSA Office of Defects Investigation
NHTSA complaint ODI 867542 (2007 Suzuki SX4) — NHTSA Office of Defects Investigation
NHTSA complaint ODI 1005414 (2008 Suzuki SX4) — NHTSA Office of Defects Investigation

Last reviewed: October 15, 2026
Written by: Saurabh K.
Editorial review: Pending
Technician review: Technician review pending

This page explains what a code usually means; it is not a substitute for a professional inspection. How we source and review · Report an error

Severity: Inspect soon

Pick your make

Most likely causes

Cause 1: Passenger seat occupancy mat or module (seat cushion assembly)

What to test first

Step 1: Have the airbag codes read with a scan tool that can talk to the airbag module, and note every code stored.

Step 2: Give your VIN to the dealer and ask whether a service bulletin or warranty extension covers this code on your car.

Step 3: Leave the diagnosis to a dealer or trained technician, who measures the circuit with the service manual procedure.