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B0091AudiAudi Q5 HubAll Audi B0091Critical Severity

B0091 on Audi Q5

Left Side Restraints Sensor 1

Factory diagnostic protocol and troubleshooting wire for fault code B0091 specifically for the Audi Q5 (2020–2026, 2.0L TFSI Turbo / 3.0L Turbo V6 (SQ5 349HP) / 55 TFSI e PHEV).

Verified OEM Telemetry & Field Repair Tree
Audi Q52020–2026
Audi Q5
SUV2.0L TFSI Turbo / 3.0L Turbo V6 (SQ5 349HP) / 55 TFSI e PHEV
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
Q5 SAE Mode $01
ECU Network Bus
500 kbps CAN-FD
ISO 15765-4 Compliant
Drivability Status
Drivable (Short Trip)
Critical urgency level
Est. Repair Cost
$150 - $450 (DIY: $60 - $180)
Parts & Labor DIY
Check B0091 On Another Audi Model:
Diagnose B0091 on Specific Q5 Model Year:

1. Symptoms of B0091 on Audi Q5

When the Engine Control Module (ECM/PCM) on your Audi Q5 (2.0L TFSI Turbo / 3.0L Turbo V6 (SQ5 349HP) / 55 TFSI e PHEV) logs fault code B0091, drivers commonly observe:

Supplemental Restraint System (SRS) / Airbag warning light illuminated on Audi Q5 (2.0L TFSI Turbo / 3.0L Turbo V6 (SQ5 349HP) / 55 TFSI e PHEV)
'Service Airbag' message on dashboard instrument cluster on Audi Q5 (2.0L TFSI Turbo / 3.0L Turbo V6 (SQ5 349HP) / 55 TFSI e PHEV)
Audi Q5 OBD-II Port Location
The 16-pin diagnostic connector is located Left side under driver steering column. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Audi Q5

Historical warranty claims and technical repair bulletins for Audi Q5 point to the following failure distribution:

55%
Corroded or damaged left side impact crash sensor (B-pillar or door sill) (Audi OEM Part)
25%
Corroded wiring harness under driver seat / driver door sill (Audi OEM Part)
12%
Loose or unseated yellow SRS connector plug (Audi OEM Part)
* Source: Synthesized from NHTSA ODI field repair telemetry and verified OEM Technical Service Bulletin (TSB) repair tree frequency percentiles for Audi Q5.

3. Step-by-Step DIY Repair Guide for Audi Q5

01
Disconnect Vehicle Battery

Disconnect battery negative cable and wait 15 minutes to fully discharge SRS backup capacitors before touching airbag components. on the Audi Q5 equipped with 2.0L TFSI Turbo / 3.0L Turbo V6 (SQ5 349HP) / 55 TFSI e PHEV.

Required Tool: 10mm Wrench
02
Locate Left Side Impact Sensor

Remove driver side door sill trim / lower B-pillar trim to access the yellow impact sensor. on the Audi Q5 equipped with 2.0L TFSI Turbo / 3.0L Turbo V6 (SQ5 349HP) / 55 TFSI e PHEV.

Required Tool: Trim Removal Tools, Torx Set
03
Inspect Wiring & Sensor Housing

Inspect sensor for water corrosion or cracked plastic housing. on the Audi Q5 equipped with 2.0L TFSI Turbo / 3.0L Turbo V6 (SQ5 349HP) / 55 TFSI e PHEV.

Required Tool: Flashlight
04
Replace Side Impact Sensor

Bolt new OEM side impact sensor into clean, rust-free ground location, torque bolt to spec, and click yellow locking connector firmly. on the Audi Q5 equipped with 2.0L TFSI Turbo / 3.0L Turbo V6 (SQ5 349HP) / 55 TFSI e PHEV.

Required Tool: Torx T30 Socket, Torque Wrench
05
Reconnect Battery and Clear SRS Codes

Reconnect battery, clear SRS trouble codes with an airbag-capable scanner, and verify light turns off after 5-second bulb check. on the Audi Q5 equipped with 2.0L TFSI Turbo / 3.0L Turbo V6 (SQ5 349HP) / 55 TFSI e PHEV.

Required Tool: SRS-Capable OBD-II Scanner
Recommended Parts & Testing Tools

Equipment for Diagnosing Audi Q5 (B0091)

Prime Fast Delivery & Verified Fitment
Direct-Fit Replacement Part

Audi Q5 OEM Replacement Sensor

4.7 / 5.0 (Verified Fit)

Direct-fit replacement assembly engineered to OEM tolerances for Audi Q5.

$45 – $95 Prime
Check Fitment on Amazon
Sensor Signal Voltage Meter

AstroAI Auto-Ranging Digital Multimeter

4.6 / 5.0 (Best Seller)

Essential for testing 0.1V–5.0V sensor reference signals, ground continuity (<0.20Ω), and harness resistance.

$29.99 Prime
View on Amazon
Top Mobile OBD-II Scanner

BlueDriver Bluetooth Pro OBDII Scan Tool

4.7 / 5.0 (50,000+ Reviews)

Reads and clears enhanced codes (ABS, Airbag, Transmission, Engine) & live freeze-frame telemetry on phone.

Compare OEM & Aftermarket Replacement Sensors for Audi Q5Verified direct-fit pricing from Denso, Bosch, Motorcraft, and ACDelco on Amazon.
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Other Common Fault Codes on Audi Q5

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Audi Q5:

4. Audi Q5 B0091 FAQs

What causes code B0091 to trigger on a Audi Q5?

On the Audi Q5 (2.0L TFSI Turbo / 3.0L Turbo V6 (SQ5 349HP) / 55 TFSI e PHEV), B0091 is most frequently caused by Corroded or damaged left side impact crash sensor (B-pillar or door sill) or Corroded wiring harness under driver seat / driver door sill.

Where is the OBD-II port located on my Audi Q5?

On the Audi Q5, the 16-pin DLC diagnostic connector is located Left side under driver steering column. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my Audi Q5 with code B0091?

Caution. Side curtain and seat airbag deployment may be disabled in a side-impact collision. Given that B0091 carries a Critical severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.