Diagnostic Procedure

WARNING: This page is about a different car, the 2018 Mazda CX-9. However, it is still accessible from the selected car via links, so may be relevant.

DTC B1207:86 (REAR BODY CONTROL MODULE) DIAGNOSTIC PROCEDURE

Step	Inspection		Action
1	VERIFY REAR BODY CONTROL MODULE (RBCM) DTCs AGAIN Clear the DTC for the rear body control module (RBCM) using the M-MDS. (See CLEARING DTC (Rear Body Control Module (RBCM)) .) Switch the ignition ON (engine off or on) and wait for 3 s or more. Retrieve the rear body control module (RBCM) DTCs using the M-MDS. (See DTC INSPECTION (Rear Body Control Module (RBCM)) .) Is the same DTC displayed?	Yes	Go to the next step.
1		No	Go to Step 9.
2	INSPECT SAS CONTROL MODULE CONNECTOR CONDITION Switch the ignition off. Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .) Disconnect the SAS control module connector. Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection. Is the connector normal?	Yes	Go to the next step.
2		No	Repair or replace the connector, then go to Step 8.
3	INSPECT REAR BODY CONTROL MODULE (RBCM) CONNECTOR CONDITION Disconnect the rear body control module (RBCM) connector. Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection. Is the connector normal?	Yes	Go to the next step.
3		No	Repair or replace the connector, then go to Step 8.
4	INSPECT WIRING HARNESS BETWEEN SAS CONTROL MODULE AND REAR BODY CONTROL MODULE (RBCM) FOR SHORT TO GROUND Verify that the SAS control module and rear body control module (RBCM) connectors are disconnected. Inspect for continuity between SAS control module terminal 3AF (wiring harness-side) and body ground. Is there continuity?	Yes	Refer to the On-Board Diagnostic Wiring Diagram (Rear Body Control Module (RBCM)) wiring diagram and verify whether or not there is a common connector between SAS control module terminal 3AF and rear body control module (RBCM) terminal 3R. If there is a common connector: Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has a short to ground. Go to Step 8.
4		No	Go to the next step.
5	INSPECT WIRING HARNESS BETWEEN SAS CONTROL MODULE AND REAR BODY CONTROL MODULE (RBCM) FOR SHORT TO POWER SUPPLY Verify that the SAS control module and rear body control module (RBCM) connectors are disconnected. Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .) Switch the ignition ON (engine off or on). Measure the voltage at the SAS control module terminal 3AF (wiring harness-side). Is the voltage 0 V?	Yes	Go to the next step.
5		No	Refer to the On-Board Diagnostic Wiring Diagram (Rear Body Control Module (RBCM)) wiring diagram and verify whether or not there is a common connector between SAS control module terminal 3AF and rear body control module (RBCM) terminal 3R. If there is a common connector: Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has a short to power supply. Go to Step 8.
6	INSPECT WIRING HARNESS BETWEEN SAS CONTROL MODULE AND REAR BODY CONTROL MODULE (RBCM) FOR OPEN CIRCUIT Switch the ignition off. Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .) Verify that the SAS control module and rear body control module (RBCM) connectors are disconnected. Inspect the wiring harness for continuity between SAS control module terminal 3AF (wiring harness-side) and rear body control module (RBCM) terminal 3R (wiring harness-side). Is there continuity?	Yes	Go to the next step.
6		No	Refer to the On-Board Diagnostic Wiring Diagram (Rear Body Control Module (RBCM)) wiring diagram and verify whether or not there is a common connector between SAS control module terminal 3AF and rear body control module (RBCM) terminal 3R. If there is a common connector: Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has an open circuit. Go to Step 8.
7	VERIFY IF MALFUNCTIONING LOCATION IS SAS CONTROL MODULE DEPENDING ON REPEATABILITY Always reconnect all disconnected connectors. Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .) Clear the DTC for the rear body control module (RBCM) using the M-MDS. (See CLEARING DTC (Rear Body Control Module (RBCM)) .) Switch the ignition ON (engine off or on) and wait for 3 s or more. Retrieve the rear body control module (RBCM) DTCs using the M-MDS. (See DTC INSPECTION (Rear Body Control Module (RBCM)) .) Is the same DTC displayed?	Yes	Replace the SAS control module, then go to the next step. (See SAS CONTROL MODULE REMOVAL/INSTALLATION [STANDARD DEPLOYMENT CONTROL SYSTEM] .) (See SAS CONTROL MODULE REMOVAL/INSTALLATION [TWO-STEP DEPLOYMENT CONTROL SYSTEM] .)
7		No	Go to Step 9.
8	VERIFY THAT REPAIRS HAVE BEEN COMPLETED Always reconnect all disconnected connectors. Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION .) Clear the DTC for the rear body control module (RBCM) using the M-MDS. (See CLEARING DTC (Rear Body Control Module (RBCM)) .) Switch the ignition ON (engine off or on) and wait for 3 s or more. Retrieve the rear body control module (RBCM) DTCs using the M-MDS. (See DTC INSPECTION (Rear Body Control Module (RBCM)) .) Is the same DTC displayed?	Yes	Repeat the inspection from Step 1. If the malfunction recurs, replace the rear body control module (RBCM). (See REAR BODY CONTROL MODULE (RBCM) REMOVAL/INSTALLATION .) Go to the next step.
8		No	Go to the next step.
9	VERIFY IF OTHER DTCs DISPLAYED Are any other DTCs displayed?	Yes	Repair or replace the malfunctioning part according to the applicable DTC troubleshooting. (See DTC TABLE (Rear Body Control Module (RBCM)) .)
9		No	DTC troubleshooting completed.