BOSCH MQB37WBR21 Radio Frequency Transceiver User Manual

BOSCH MQB37WBR21 Radio Frequency Transceiver

• Product: BCM (Body Computer Module)
• Brand Name: Bosch
• Model Name: BR21
• Hardware version: HW24

General Description

The radio frequency transceiver is part of a body computer ECU. The ECU incorporates several HW-inputs and HW-outputs, which monitor and control body computer functionalities in a car (e.g. light control and central door lock-ing).
The ECU consists of a plastic housing, PCB, electronic components, and connector pins. The radio frequency transceiver functionality will be explained in more detail in the below-documented sections.

HW Interface

The radio frequency transceiver is supplied via the specified connector pins. The antenna of the radio frequency transceiver is a PCB-edge antenna, which is incorporated in the PCB of the ECU.

Connector Position on housing

Supply and GND pins:

• Supply (+): Pin-No# A66, A73, C1, C73
• GND (-): Pin-No# A63, C63

LED+ Pin is connected to Pin A59.

Normal Operating conditions:

• Supply Voltage: : 9V to 16V, typ. 12V
• Environment Temperature: : -40°C to +80°C

System Block Diagram MQB37W BCM

The below-drawn block diagram of the MQB BCM shows the main function blocks of the ECU.

In section 0, the design of the radio frequency transceiver is outlined.

Block Diagram of inbuilt Radio Frequency Transceiver

The radio frequency transceiver has the following key data:

Functional description

The radio frequency transceiver is part of a remote keyless entry system of a vehicle central door locking system. This vehicle central door locking system consist out of

• Remote control key with UHF transmitter (NOT part of the MQB BCM)
• Radiofrequency transceiver with PCB-Antenna (part of the MQB BCM)
• Door ECU, which can drive the car door locks to lock or unlock the car (NOT part of the MQB BCM)
• Door locks for the central door locking functionality (NOT part of the MQB BCM)

The transceiver has a self-polling mode and is permanently scanning for valid key data, with matching characteristics.
(Note: This data are typically received when a valid remote control key is in range and one of its push buttons is pressed.)
When the data are matching the characteristics, the transceiver will hand over this data to the microcontroller of the MQB BCM. With the help of this microcontroller, it is validated, whether this data have been transmitted from the authorized remote control key. When the validation was successful, the MQB BCM will send this information via a CAN network to the door ECU. This door ECU will drive the connected door lock according to the wish of the operator, who pressed the push button of the remote control key. Hence the doors will be locked or unlocked. The MQB BCM needs to be programmed by the OEM, after installing the ECU into the car. Once programmed, the transceiver is operable directly after applying power to the connector pins.

Regulatory notice

for FCC: §15.19

This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions:

1. This device may not cause harmful interference, and
2. This device must accept any interference received, including interference that may cause undesired operation.

for USA: §15.21:

NOTICE: Changes or modifications made to this equipment not expressly approved by Robert Bosch GmbH may void the FCC authorization to operate this equipment.

for Canada: RSS-GEN, 8.4: 

This device contains license-exempt transmitter(s)/receiver(s) that comply with Innovation, Science, and Economic Development Canada’s license-exempt RSS(s). Operation is subject to the following two conditions:

1. This device may not cause interference.
2. This device must accept any interference, including interference that may cause undesired operation of the device.

Product pictures

Topside:

Bottom side: