Body Control Module (BCM) Removal/Installation

WARNING: This page is about a different car, the 2016 Mazda CX-3. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

The BCM prior to replacement stores the vehicle specification information.
A new BCM does not store any vehicle specification information.
When replacing the BCM, the following two methods are available for storing the vehicle specification information in the BCM.
- Auto configuration: When the ignition is switched ON, the BCM reads the vehicle specification information sent via CAN communication from the instrument cluster, and stores the vehicle specification information. However, because the personalization information is returned to the initial values, it is necessary to store the personalization information before replacing the BCM and perform the resetting procedure for the personalization information.
- Configuration using M-MDS: The BCM reads the vehicle specification information and the personalization information from the pre-replacement BCM, and writes the information to a new BCM.
When performing the auto configuration, store the personalization information before replacing the BCM and perform the resetting procedure for the personalization information because the personalization information is returned to the initial values.

If the BCM is replaced and the auto configuration is not performed, perform the configuration using the M-MDS. (See BODY CONTROL MODULE (BCM) CONFIGURATION (USING READ/WRITE FUNCTION) .)
Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION .)
Remove the following parts:
- Front scuff plate (LH). (See FRONT SCUFF PLATE REMOVAL/INSTALLATION .)
- Front side trim (LH). (See FRONT SIDE TRIM REMOVAL/INSTALLATION .)
- Driver-side lower panel (See DRIVER-SIDE LOWER PANEL REMOVAL/INSTALLATION .)
- Adaptive front lighting system (AFS) control module (with adaptive front lighting system (AFS)) (See ADAPTIVE FRONT LIGHTING SYSTEM (AFS) CONTROL MODULE REMOVAL/INSTALLATION .)
Disconnect the connector.

Fig 1: Identifying BCM Connector
Courtesy of MAZDA MOTORS CORP.
While pressing the BCM tab in the direction of arrow (1) shown in the figure, pull it in the direction of arrow (2) to detach the tab from the body.

Fig 2: Pressing BCM Tab
Courtesy of MAZDA MOTORS CORP.
Pull the BCM in the direction of the arrow shown in the figure and detach the hook from the body.

Fig 3: Pulling Out BCM
Courtesy of MAZDA MOTORS CORP.
Rotate the BCM in the direction of the arrow shown in the figure and remove it.

Fig 4: Rotating BCM
Courtesy of MAZDA MOTORS CORP.
Disconnect the connectors.

Fig 5: Identifying BCM Connector
Courtesy of MAZDA MOTORS CORP.
Remove the BCM.
Install in the reverse order of removal.
If the BCM is replaced and the auto configuration is performed, perform the auto configuration using the following procedure.
1. Switch the ignition ON (engine off or on) and wait for 1 min or more.
2. Switch the ignition off and wait for 3 s or more.
3. Switch the ignition ON (engine off or on) and complete the BCM auto configuration.
4. Using the M-MDS, verify that DTCs U2300:54, U2300:55, or U2300:56 is not displayed.
  - If DTC U2300:54, U2300:55, or U2300:56 is displayed, go to the DTC troubleshooting procedure. (See DTC U2300:54 [BCM] .) (See DTC U2300:55 [BCM] .) (See DTC U2300:56 [BCM] .)