BodyB121C
CautionSeverity: Caution - get it checked when you can
IGBT 3 drive function failure
Key terms: Control module: a small computer that runs one part of the car
1What it means in plain English
A body system has a fault. Depending on the make, this range can include airbags and seat belts, windows, locks and climate control, and also charging, brake, oil or coolant sensors.
2Common causes
- Wiring or connector fault
- Faulty sensor or switch
- Water or corrosion in a connector
- Control module fault
- Low battery voltage
3Can I drive?
Do not assume this code is safe to drive. If it concerns the brakes, brake vacuum, charging/alternator, engine oil or coolant, have it diagnosed before driving. Airbags or seat belts may not work in a crash, and a brake or charging fault can leave the car unsafe or stranded. For convenience systems (windows, locks, climate), have it checked when convenient.
This page gives general information. It is not professional advice. For a definite diagnosis and a repair quote, ask a qualified mechanic to inspect the car.
4Brand data 8
| Brand | Code | Description | System |
|---|---|---|---|
| BYD | B121C | IGBT 3 drive function failure Brand | Body |
| DFFS | B121C | Information from hybrid electronic control unit 1 is lost Brand | Body |
| Geely | B121C | Front Row Right Side Side Airbag Igniter Resistance High Brand | Body |
| Honda | B121C | No description available | Body |
| Land Rover | B121C | No description available | Body |
| Mitsubishi | B121C | No description available | Body |
| Peugeot | B121C | No description available | Body |
| Proton | B121C | No description available | Body |
Legend: SAE is the generic J2012 description; Brand is text taken from that manufacturer’s data. Manufacturer rows keep the wording and language of the source data, and non-English text is tagged so screen readers pronounce it correctly.
5Extended variant codes 10
These 7-character codes are manufacturer-specific variants of B121C and may be reported by some scan tools.
| Brand | Code | Description | System |
|---|---|---|---|
| Mahindra | B121C11 | C-Pillar Right SRSU Short To Ground Brand | Body |
| Mahindra | B121C12 | C-Pillar Right SRSU Short To Battery Brand | Body |
| Mahindra | B121C13 | C-Pillar Right SRSU Open Circuit Brand | Body |
| Mercedes-Benz | B121C49 | The actuator motor for air flap 'Central air vent' has a malfunction. There is an internal electrical fault. Brand | Body |
| Volvo | B121C49 | Check to see if DTC IAM- is stored Brand | Body |
| Mercedes-Benz | B121C51 | The actuator motor for air flap 'Central air vent' has a malfunction. The component is not programmed. Brand | Body |
| Mahindra | B121C64 | C-Pillar Right SRSU Configuration Error Brand | Body |
| Mercedes-Benz | B121C79 | The actuator motor for air flap 'Central air vent' has a malfunction. The mechanical connection has failed. Brand | Body |
| Mahindra | B121C81 | C-Pillar Right SRSU Communication Error Brand | Body |
| Mahindra | B121C96 | C-Pillar Right SRSU Internal Error Brand | Body |
6Related codes
Browse Bxxx codes or B121xx codes.