Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC : B122C (A-B5)
DTC B122C or DTC screen A-B5 : Air Quality Sensor Internal Error
| DTC Description | DTC |
|---|---|
| B122C Air quality sensor internal error |
DTC (AC)
- Problem verification
-1. Clear the DTCs with the HDS. How to Clear DTCs
Clear DTCs
-2. Turn the vehicle to the OFF (LOCK) mode then the ON mode.
-3. Do the Self-Diagnostic Function with the HDS or the climate control unit .
-4. Check for DTCs.
DTC Description DTC B122C Air quality sensor internal error Is DTC B122C or screen A-B5 indicated?
YES
Replace the air quality sensor .
NO
Intermittent failure, the air quality sensor is OK at this time
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.