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 P33B3-00: External BBC Circuit [12/2024 - ]: Description
When the engine is started (high electrical load) from engine stopped by the stop and start control, the external backup boost converter (eco run vehicle converter assembly) supplements battery voltage in order to prevent the function from being disabled due to decrease in power source voltage supplied to the active noise control system.
After receiving a request from the engine stop and start ECU, the external backup boost converter (eco run vehicle converter assembly) helps maintain the power source voltage if the battery voltage drops due to the high electrical load when the engine is restarted by stop and start control. The DON2 terminal of the external backup boost converter (eco run vehicle converter assembly) receives power supply voltage supplement requests from the engine stop and start ECU and switches from idle mode to supplement mode.
When the engine is started by the stop and start control, if the external backup boost converter (eco run vehicle converter assembly) does not maintain the specified voltage, an error is sent to the engine stop and start ECU. Then, the engine stop and start ECU stores DTC P33B3-00.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | MIL | Warning Indicate | DTC Output from | Priority | Note |
|---|---|---|---|---|---|---|---|---|
| P33B3-00 | External BBC Circuit | Any of the following conditions are met for 1 second or more (2 trip detection logic):
|
|
Does not come on | Does not come on | Stop and Start | A | SAE Code: P33B3 |
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.