Determination Procedure

WARNING: This page is about a different car, the 2020 Mazda CX-30. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION:

When disconnecting the connector, verify that there is no looseness, damage, deformation, corrosion, or poor connection of the connector terminals.
When inspecting the connector, touch it with a paper clip or similar thin pin without directly inserting a tester probe into the terminal.
Disconnect the negative battery cable before performing any work that requires handling of connectors.

DETERMINING SHORT BETWEEN CIRCUITS LOCATION (CAN-BUS No. 5, US) - DIAGNOSTIC PROCEDURE

Step	Inspection		Action
1	INSPECT BODY CONTROL MODULE (BCM) FOR SHORT BETWEEN CIRCUITS Switch the ignition off. Disconnect the negative battery cable. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .) Disconnect the connector 2 which has body control module (BCM) terminals 2E and 2G. Connect the negative battery cable. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .) Switch the ignition ON (engine off). Measure the voltage at body control module (BCM) terminals 2E and 2G (wiring harness side). Is the voltage at body control module (BCM) terminals 2E and 2G (wiring harness side) the same?	Yes	Go to the next step.
1		No	Replace the body control module (BCM) because there is a short between circuits in the body control module (BCM). (See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION (US) .)
2	INSPECT CAN LINE BETWEEN CONNECTOR C-06 AND BODY CONTROL MODULE (BCM) FOR SHORT BETWEEN CIRCUITS Switch the ignition off. Disconnect the negative battery cable. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .) Disconnect the connector C-06. Connect the connector 2 which has body control module (BCM) terminals 2E and 2G. Connect the negative battery cable. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .) Switch the ignition ON (engine off). Measure the voltage at body control module (BCM) terminals 2E and 2G. Is the voltage at body control module (BCM) terminals 2E and 2G the same?	Yes	Repair or replace the wiring harness between the body control module (BCM) and connector C-06 because the wiring harness is shorted between circuits.
2		No	Go to the next step.
3	INSPECT CAN LINE BETWEEN CONNECTOR C-47 AND CONNECTOR C-06 FOR SHORT BETWEEN CIRCUITS Switch the ignition off. Disconnect the negative battery cable. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .) Disconnect the connector C-47. Connect the connector C-06. Connect the negative battery cable. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .) Switch the ignition ON (engine off). Measure the voltage at body control module (BCM) terminals 2E and 2G. Is the voltage at body control module (BCM) terminals 2E and 2G the same?	Yes	Repair or replace the wiring harness between connector C-47 and connector C-06 because the wiring harness is shorted between circuits.
3		No	Go to the next step.
4	INSPECT CAN LINE BETWEEN PARKING ASSIST UNIT (OPTICAL)/360° VIEW MONITORING CAMERA UNIT AND CONNECTOR C-47 FOR SHORT BETWEEN CIRCUITS Switch the ignition off. Disconnect the negative battery cable. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .) Inspect for continuity between parking assist unit (optical)/360° view monitoring camera unit terminals 1C and 1A. Is there continuity?	Yes	Go to the next step.
4		No	Go to Step 6.
5	INSPECT PARKING ASSIST UNIT (OPTICAL)/360° VIEW MONITORING CAMERA UNIT FOR SHORT BETWEEN CIRCUITS Disconnect the parking assist unit (optical)/360° view monitoring camera unit connector. Inspect for continuity between parking assist unit (optical)/360° view monitoring camera unit terminals 1C and 1A (wiring harness side). Is there continuity?	Yes	Repair or replace the wiring harness between the parking assist unit (optical)/360° view monitoring camera unit and connector C-47 because the wiring harness is shorted between circuits.
5		No	Replace the parking assist unit (optical)/360° view monitoring camera unit because there is a short between circuits in the parking assist unit (optical)/360° view monitoring camera unit. (See 360DEGREES VIEW MONITOR CONTROL MODULE REMOVAL/INSTALLATION (US) (See PARKING ASSIST UNIT (OPTICAL) REMOVAL/INSTALLATION (US) .)
6	INSPECT JB No. 1 FOR SHORT BETWEEN CIRCUITS Disconnect the connector C-46. Connect the connector C-47. Connect the negative battery cable. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .) Switch the ignition ON (engine off). Measure the voltage at body control module (BCM) terminals 2E and 2G. Is the voltage at body control module (BCM) terminals 2E and 2G the same?	Yes	Replace the JB No. 1 because there is a short between circuits in the JB No. 1.
6		No	Go to the next step.
7	INSPECT CAN LINE BETWEEN CONNECTOR C-13 AND CONNECTOR C-46 FOR SHORT BETWEEN CIRCUITS Switch the ignition off. Disconnect the negative battery cable. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .) Disconnect the connector C-13. Connect the connector C-46. Connect the negative battery cable. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .) Switch the ignition ON (engine off). Measure the voltage at body control module (BCM) terminals 2E and 2G. Is the voltage at body control module (BCM) terminals 2E and 2G the same?	Yes	Repair or replace the wiring harness between connector C-13 and connector C-46 because the wiring harness is shorted between circuits.
7		No	Go to the next step. (with driver monitoring (DM)) Go to Step 12. (without driver monitoring (DM))
8	INSPECT CAN LINE BETWEEN CONNECTOR C-39 AND CONNECTOR C-13 FOR SHORT BETWEEN CIRCUITS Switch the ignition off. Disconnect the negative battery cable. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .) Disconnect the connector C-39. Connect the connector C-13. Connect the negative battery cable. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .) Switch the ignition ON (engine off). Measure the voltage at body control module (BCM) terminals 2E and 2G. Is the voltage at body control module (BCM) terminals 2E and 2G the same?	Yes	Repair or replace the wiring harness between connector C-39 and connector C-13 because the wiring harness is shorted between circuits.
8		No	Go to the next step.
9	INSPECT CAN LINE BETWEEN DRIVER MONITORING CAMERA UNIT AND CONNECTOR C-39 FOR SHORT BETWEEN CIRCUITS Switch the ignition off. Disconnect the negative battery cable. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .) Inspect for continuity between driver monitoring camera unit terminals 1F and 1E. Is there continuity?	Yes	Go to the next step.
9		No	Go to Step 11.
10	INSPECT DRIVER MONITORING CAMERA UNIT FOR SHORT BETWEEN CIRCUITS Disconnect the driver monitoring camera unit connector. Inspect for continuity between driver monitoring camera unit terminals 1F and 1E (wiring harness side). Is there continuity?	Yes	Repair or replace the wiring harness between the driver monitoring camera unit and connector C-39 because the wiring harness is shorted between circuits.
10		No	Replace the driver monitoring camera unit because there is a short between circuits in the driver monitoring camera unit. (See DRIVER MONITORING CAMERA UNIT REMOVAL/INSTALLATION (US) .)
11	INSPECT CAN LINE BETWEEN CONNECTOR C-16 AND CONNECTOR C-39 FOR SHORT BETWEEN CIRCUITS Switch the ignition off. Disconnect the negative battery cable. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .) Disconnect the connector C-16. Connect the connector C-39. Connect the negative battery cable. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .) Switch the ignition ON (engine off). Measure the voltage at body control module (BCM) terminals 2E and 2G. Is the voltage at body control module (BCM) terminals 2E and 2G the same?	Yes	Repair or replace the wiring harness between connector C-16 and connector C-39 because the wiring harness is shorted between circuits.
11		No	Go to Step 13.
12	INSPECT CAN LINE BETWEEN CONNECTOR C-16 AND CONNECTOR C-13 FOR SHORT BETWEEN CIRCUITS Switch the ignition off. Disconnect the negative battery cable. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .) Disconnect the connector C-16. Connect the connector C-13. Connect the negative battery cable. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .) Switch the ignition ON (engine off). Measure the voltage at body control module (BCM) terminals 2E and 2G. Is the voltage at body control module (BCM) terminals 2E and 2G the same?	Yes	Repair or replace the wiring harness between connector C-16 and connector C-13 because the wiring harness is shorted between circuits.
12		No	Go to the next step.
13	INSPECT CAN LINE BETWEEN CONNECTOR C-27 AND CONNECTOR C-16 FOR SHORT BETWEEN CIRCUITS Switch the ignition off. Disconnect the negative battery cable. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .) Disconnect the connector C-27. Connect the connector C-16. Connect the negative battery cable. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .) Switch the ignition ON (engine off). Measure the voltage at body control module (BCM) terminals 2E and 2G. Is the voltage at body control module (BCM) terminals 2E and 2G the same?	Yes	Repair or replace the wiring harness between connector C-27 and connector C-16 because the wiring harness is shorted between circuits.
13		No	Go to the next step.
14	INSPECT FORWARD SENSING CAMERA (FSC) FOR SHORT BETWEEN CIRCUITS Switch the ignition off. Disconnect the negative battery cable. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .) Disconnect the forward sensing camera (FSC) connector. Inspect for continuity between forward sensing camera (FSC) terminals B and A (wiring harness side). Is there continuity?	Yes	Repair or replace the wiring harness between the forward sensing camera (FSC) and connector C-27 because the wiring harness is shorted between circuits.
14		No	Replace the forward sensing camera (FSC) because there is a short between circuits in the forward sensing camera (FSC). (See FORWARD SENSING CAMERA (FSC) REMOVAL/INSTALLATION .)