B1135: Pretensioner Squib Circuit

Circuit fault

What B1135 means

A pretensioner squib is the igniter that fires the charge inside a seat belt retractor or buckle to take slack out of the belt during a crash. The airbag control module monitors that igniter circuit for resistance in a set range. B1135 means the reading on a pretensioner circuit fell outside that range, which is enough for the module to disable the restraint system.

What this code does not tell you on its own is the seating position or whether the fault is an open or a short. Toyota and Lexus use position specific codes elsewhere in the range, so B1135 should be read alongside the freeze frame data and the factory code chart for that model year. Confirm the position before removing trim or ordering a belt.

Common causes

• A pretensioner that already deployed and reads out of range from the moment it is installed
• The yellow connector at the retractor or buckle not fully latched after trim work
• Harness damage at the B pillar, sill, or seat rail where the pretensioner wiring runs
• An igniter winding that has failed open or shorted internally
• Corroded terminals from water entering at a door seal or floor pan
• Module connector pins spread or backed out from an earlier repair

Crash data or hardware fault?

The code tracks a live circuit reading, which is why it sits in the circuit family rather than with crash data. It reflects the wiring as it is right now and it clears when the circuit reads correctly again. Crash data, by contrast, is a permanent entry written at deployment that a scan tool cannot touch.

Does our reset clear it?

Because this is a live circuit complaint, a reset on its own does not resolve it. The module measures the pretensioner loop again within seconds of power up and stores the code right back. Identify the position, repair or replace what is out of range, and then decide about the module. Our mail in reset applies when that module is also holding crash data from a deployment, and you can call 501-988-0611 if you want help reading the module before you send it.

Which makes throw it

Lexus and Toyota both list B1135. Because the definition on this one is general, cross reference the code against the factory chart for the exact model and year rather than assuming the same belt position on every vehicle that stores it.

What to do next

Pull the full code set and the freeze frame before touching anything, since the companion codes usually reveal which pretensioner the module is complaining about. Then verify with the factory chart for that chassis. Once the position is known, check whether the pretensioner has already fired, reseat the connector, and measure the loop at both ends. We carry genuine OEM seat belts and pretensioners and can talk through the readings at 501-988-0611. Related codes: B1000, B1195, B1B03.