Meta Description: B0140 is a Toyota manufacturer-specific SRS code associated with the driver far-side or center airbag circuit on applicable newer Toyota vehicles. Learn the symptoms, causes, component location, diagnosis, repair, and cost.
What Does B0140 Mean?
B0140 is a manufacturer-specific SRS code associated with the driver far-side / center airbag circuit on applicable newer Toyota vehicles.
This airbag is part of the vehicle's advanced supplemental restraint system and is designed to provide additional protection in certain crash conditions. Toyota applications do not all use the same SRS architecture, so the exact description and circuit configuration for B0140 must be verified against the specific vehicle and model year.
Code Type: Manufacturer-Specific
DTC: B0140
System: SRS / Airbag
Fault Area: Driver far-side / center airbag circuit
Responsible Component: Driver far-side / center airbag assembly and its SRS circuit
Important: B0140 should not automatically be interpreted as a universal Toyota airbag code. Toyota uses different SRS DTC architectures across model generations. Some newer Toyota applications associate B0140/B0141 with the driver far-side or center airbag, while other generic databases assign B0140 completely different meanings. Always verify the code using the vehicle-specific Toyota service information. 1
Common Causes of B0140
- Damaged wiring in the driver far-side / center airbag circuit
- Loose or incorrectly connected SRS connector
- Damaged connector terminals
- Open or shorted airbag circuit
- Damaged airbag squib or airbag assembly
- Wiring damage following interior or seat repair
- Corrosion or moisture contamination
- Fault in the SRS control module
Symptoms of B0140
- SRS or airbag warning light remains illuminated
- B0140 stored in the SRS module
- Additional SRS codes may be present
- The affected airbag function may be disabled
- The vehicle may otherwise drive normally
Is B0140 Serious?
Yes. B0140 concerns the SRS system. If the fault remains active, the affected airbag may not operate as intended during a collision.
Can I Drive With B0140?
The vehicle may continue to drive normally because B0140 is not an engine or transmission fault. However, an illuminated SRS warning light indicates that the restraint system requires diagnosis. The fault should be repaired as soon as practical.
Where Is the B0140 Component Located?
The exact location depends on the Toyota model and SRS configuration.
On vehicles equipped with a driver far-side or center airbag, the airbag assembly is generally positioned within the vehicle's interior near the centerline between the driver and passenger seating areas or within the applicable seat/interior structure.
Because Toyota uses different designs, always use the vehicle-specific repair manual to identify the exact airbag location and connector.
Component Responsible for B0140
- Driver far-side / center airbag assembly
- Airbag squib circuit
- SRS wiring harness
- SRS connectors
- Center airbag sensor assembly / SRS control module
How to Diagnose B0140
1. Scan the SRS System
Use a scan tool capable of communicating with the Toyota SRS system. Record B0140 and any additional SRS codes before clearing the system.
Additional DTCs can help identify whether the problem is isolated to the airbag circuit or associated with the SRS control system.
2. Verify the Exact Toyota DTC Description
Before replacing any component, confirm the exact B0140 description for the vehicle's model year and SRS configuration.
This step is particularly important because Toyota has changed SRS architectures and DTC assignments between generations.
3. Inspect the Airbag Wiring
Inspect the wiring and connectors associated with the driver far-side / center airbag.
Look for:
- Damaged insulation
- Pinched or crushed wiring
- Loose connectors
- Bent terminals
- Corrosion
- Water contamination
- Evidence of previous interior repairs
4. Check the SRS Circuit
With the SRS system safely disabled according to the Toyota service procedure, test the circuit using the manufacturer's approved diagnostic procedure.
Do not assume that a resistance value or terminal identification from another Toyota model applies to the vehicle being diagnosed.
5. Check the Airbag Assembly
If the wiring and connectors are good, the affected driver far-side / center airbag assembly may require further testing.
Toyota-specific SRS simulation equipment and procedures should be used where specified by the manufacturer.
6. Check the SRS Control Module
If the airbag circuit and assembly pass the applicable tests, further diagnosis of the SRS control module may be required.
Do not replace the SRS module before confirming that the external wiring and airbag circuit are not responsible for the fault.
SRS Safety Note: Airbag circuits contain pyrotechnic devices. Follow the exact Toyota SRS safety procedure before servicing the system. Disconnect the negative battery terminal and wait the manufacturer-specified period before handling SRS connectors. Never apply battery voltage to an airbag circuit. Do not directly measure a squib with a conventional multimeter unless the manufacturer specifically provides an approved procedure and equipment.
How to Fix B0140
- Reconnect a loose or improperly seated SRS connector.
- Repair damaged wiring according to the Toyota repair procedure.
- Replace damaged SRS terminals or connectors when required.
- Repair or replace the affected harness.
- Replace the driver far-side / center airbag assembly if confirmed faulty.
- Replace the SRS control module only after the circuit has been properly diagnosed.
- Clear the DTC and perform the required SRS verification procedure after repair.
Common Repair Mistakes
- Assuming B0140 has the same meaning on every Toyota
- Replacing the airbag before checking its wiring
- Replacing the SRS module without testing the circuit
- Clearing the code without repairing the underlying fault
- Using a conventional multimeter directly on the squib
- Using an improvised resistor instead of approved SRS diagnostic equipment
B0140 Repair Cost
Repair cost depends on the vehicle and the component causing the fault.
- Connector repair: usually the lowest-cost repair
- Wiring repair: moderate depending on accessibility
- Airbag assembly: potentially expensive
- SRS control module: potentially expensive because of module cost and possible initialization requirements
Proper diagnosis should be completed before purchasing an airbag or SRS module.
Related B0140 Codes
Passenger Knee Airbag Squib Family
Passenger Knee Airbag Squib Family
Related Driver Far-Side / Center Airbag Code
Driver Frontal Airbag Squib Family
FAQ
What does B0140 mean on a Toyota?
On applicable newer Toyota vehicles, B0140 is associated with the driver far-side / center airbag circuit.
Is B0140 a universal Toyota code?
No. Toyota SRS DTC definitions vary by model, model year, and SRS configuration. The exact factory description should be verified before replacing components.
Is B0140 an engine code?
No. B0140 is a body/SRS-related DTC and is not an engine or transmission code.
Can wiring cause B0140?
Yes. Damaged wiring, poor connector contact, an open circuit, or a short circuit can cause an SRS circuit fault. The exact failure mode must be determined from the vehicle-specific Toyota diagnostic procedure.