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 B18A1, B1E51: Left/Right Side BSI Radar Unit Internal Circuit Error
NOTE: Before you troubleshoot, review the general troubleshooting information .
| DTC Description | DTC |
|---|---|
| B18A1 Left Side BSI Radar Unit Internal Circuit Error | |
| B1E51 Right Side BSI Radar Unit Internal Circuit Error |
DTC (BSI)
- Problem verification
-1. Turn the vehicle to the ON mode.
- 2. Clear the DTC with the HDS.
- 3. Turn the vehicle to the OFF (LOCK) mode.
- 4. Turn the vehicle to the ON mode, then wait for at least 5 seconds.
- 5. Check for DTCs with the HDS.
DTC Description DTC B18A1 Left Side BSI Radar Unit Internal Circuit Error B1E51 Right Side BSI Radar Unit Internal Circuit Error Are any DTCs indicated?
YES
Replace the appropriate BSI radar unit .
NO
Intermittent failure, the system is OK at this time. Refer to intermittent failures troubleshooting .
NO RELATED
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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.