BodyB1840
CautionSeverity: Caution - get it checked when you can
Consistency fault between electronic key reader start request and engine start switch pressing
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 16
| Brand | Code | Description | System |
|---|---|---|---|
| Mercedes-Benz | B1840 | No description available | Body |
| Chery | B1840 | MMI temperature high Brand | Body |
| Daewoo | B1840 | No description available | Body |
| DFFS | B1840 | Consistency fault between electronic key reader start request and engine start switch pressing Brand | Body |
| GM | B1840 | driver lumbar up switch circuit malfunction Brand | Body |
| Holden | B1840 | Lumbar Support Up Switch Circuit Brand | Body |
| Honda | B1840 | No description available | Body |
| Hyundai | B1840 | No description available | Body |
| Opel | B1840 | driver lumbar up switch circuit malfunction Brand | Body |
| Peugeot | B1840 | No description available | Body |
| Proton | B1840 | No description available | Body |
| Saab | B1840 | driver lumbar up switch circuit malfunction Brand | Body |
| MG (SAIC) | B1840 | ECU Slave Controller Program Sequence Error Brand | Body |
| Subaru | B1840 | No description available | Body |
| Suzuki | B1840 | Vehicle Speed Invalid Data Brand | Body |
| Toyota | B1840 | Consistency fault between electronic key reader start request and engine start switch pressing Brand | 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 1
These 7-character codes are manufacturer-specific variants of B1840 and may be reported by some scan tools.
| Brand | Code | Description | System |
|---|---|---|---|
| SsangYong | B184000 | Block or dirty sensor Brand | Body |
6Related codes
Browse Bxxx codes or B184xx codes.