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.

DETERMINING SHORT TO GROUND LOCATION (CAN-BUS No. 4, US) - DIAGNOSTIC PROCEDURE

Step	Inspection		Action
1	INSPECT FOR SHORT TO GROUND BETWEEN BODY CONTROL MODULE (BCM) AND CONNECTOR C-08 Switch the ignition off. Disconnect the negative battery cable. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US)) Disconnect the connector C-08. Inspect for continuity at the following terminals: Between body control module (BCM) terminal 2D and body ground Between body control module (BCM) terminal 2B and body ground Is there continuity?	Yes	Go to the next step.
1		No	Go to Step 3.
2	INSPECT CAN LINE IN BODY CONTROL MODULE (BCM) FOR SHORT TO GROUND Disconnect the connector 2 which has body control module (BCM) terminals 2D and 2B. Inspect for continuity at the following terminals: Between body control module (BCM) terminal 2D (wiring harness side) and body ground Between body control module (BCM) terminal 2B (wiring harness side) and body ground Is there continuity?	Yes	Repair or replace the wiring harness between the connector C-08 and body control module (BCM) because the wiring harness is shorted to ground.
2		No	Replace the body control module (BCM) because there is a short to ground in the body control module (BCM). (See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION (US) .)
3	INSPECT FOR SHORT TO GROUND BETWEEN CONNECTOR C-08 AND CONNECTOR C-69 Disconnect the connector C-69. Connect the connector C-08. Inspect for continuity at the following terminals: Between body control module (BCM) terminal 2D and body ground Between body control module (BCM) terminal 2B and body ground Is there continuity?	Yes	Repair or replace the wiring harness between the connector C-08 and connector C-69 because the wiring harness is shorted to ground.
3		No	Go to the next step.
4	INSPECT FOR SHORT TO GROUND BETWEEN ELECTRICAL SUPPLY UNIT (ESU) AND CONNECTOR C-69 Inspect for continuity at the following terminals: Between electrical supply unit (ESU) terminal 1X and body ground Between electrical supply unit (ESU) terminal 1W and body ground Is there continuity?	Yes	Go to the next step.
4		No	Go to Step 6. (with parking sensor system) Go to Step 11. (without parking sensor system)
5	INSPECT CAN LINE IN ELECTRICAL SUPPLY UNIT (ESU) FOR SHORT TO GROUND Disconnect the electrical supply unit (ESU) connector. Inspect for continuity at the following terminals: Between electrical supply unit (ESU) terminal 1X (wiring harness side) and body ground Between electrical supply unit (ESU) terminal 1W (wiring harness side) and body ground Is there continuity?	Yes	Repair or replace the wiring harness between the electrical supply unit (ESU) and connector C-69 because the wiring harness is shorted to ground.
5		No	Replace the electrical supply unit (ESU) because there is a short to ground in the electrical supply unit (ESU). (See ELECTRICAL SUPPLY UNIT (ESU) REMOVAL/INSTALLATION .)
6	INSPECT FOR SHORT TO GROUND BETWEEN CONNECTOR C-58 AND CONNECTOR C-69 Disconnect the connector C-58. Connect the connector C-69. Inspect for continuity at the following terminals: Between body control module (BCM) terminal 2D and body ground Between body control module (BCM) terminal 2B and body ground Is there continuity?	Yes	Repair or replace the wiring harness between the connector C-58 and connector C-69 because the wiring harness is shorted to ground.
6		No	Go to the next step.
7	INSPECT FOR SHORT TO GROUND BETWEEN PARKING ASSIST UNIT (ULTRASONIC) AND CONNECTOR C-58 Inspect for continuity at the following terminals: Between parking assist unit (ultrasonic) terminal 1X and body ground Between parking assist unit (ultrasonic) terminal 1Z and body ground Is there continuity?	Yes	Go to the next step.
7		No	Go to Step 9.
8	INSPECT CAN LINE IN PARKING ASSIST UNIT (ULTRASONIC) FOR SHORT TO GROUND Disconnect the parking assist unit (ultrasonic) connector. Inspect for continuity at the following terminals: Between parking assist unit (ultrasonic) terminal 1X (wiring harness side) and body ground Between parking assist unit (ultrasonic) terminal 1Z (wiring harness side) and body ground Is there continuity?	Yes	Repair or replace the wiring harness between the parking assist unit (ultrasonic) and connector C-58 because the wiring harness is shorted to ground.
8		No	Replace the parking assist unit (ultrasonic) because there is a short to ground in the parking assist unit (ultrasonic). (See PARKING ASSIST UNIT (ULTRASONIC) REMOVAL/INSTALLATION .)
9	INSPECT FOR SHORT TO GROUND BETWEEN REAR SIDE RADAR SENSOR (RH) AND CONNECTOR C-70 Disconnect the connector C-70. Inspect for continuity at the following terminals: Between rear side radar sensor (RH) terminal C and body ground Between rear side radar sensor (RH) terminal D and body ground Is there continuity?	Yes	Go to the next step.
9		No	Repair or replace the wiring harness between connector C-70 and connector C-58 because the wiring harness is shorted to ground.
10	INSPECT CAN LINE IN REAR SIDE RADAR SENSOR (RH) FOR SHORT TO GROUND Disconnect the rear side radar sensor (RH) connector. Inspect for continuity at the following terminals: Between rear side radar sensor (RH) terminal C (wiring harness side) and body ground Between rear side radar sensor (RH) terminal D (wiring harness side) and body ground Is there continuity?	Yes	Repair or replace the wiring harness between the rear side radar sensor (RH) and connector C-70 because the wiring harness is shorted to ground.
10		No	Replace the rear side radar sensor (RH) because there is a short to ground in the rear side radar sensor (RH). (See REAR SIDE RADAR SENSOR REMOVAL/INSTALLATION .)
11	INSPECT FOR SHORT TO GROUND BETWEEN CONNECTOR C-68 AND CONNECTOR C-69 Disconnect the connector C-68. Connect the connector C-69. Inspect for continuity at the following terminals: Between body control module (BCM) terminal 2D and body ground Between body control module (BCM) terminal 2B and body ground Is there continuity?	Yes	Repair or replace the wiring harness between the connector C-68 and connector C-69 because the wiring harness is shorted to ground.
11		No	Go to the next step.
12	INSPECT FOR SHORT TO GROUND BETWEEN CONNECTOR C-70 AND CONNECTOR C-68 Disconnect the connector C-70. Connect the connector C-68 Inspect for continuity at the following terminals: Between body control module (BCM) terminal 2D and body ground Between body control module (BCM) terminal 2B and body ground Is there continuity?	Yes	Repair or replace the wiring harness between the connector C-70 and connector C-68 because the wiring harness is shorted to ground.
12		No	Go to the next step.
13	INSPECT CAN LINE IN REAR SIDE RADAR SENSOR (RH) FOR SHORT TO GROUND Disconnect the rear side radar sensor (RH) connector. Inspect for continuity at the following terminals: Between rear side radar sensor (RH) terminal C (wiring harness side) and body ground Between rear side radar sensor (RH) terminal D (wiring harness side) and body ground Is there continuity?	Yes	Repair or replace the wiring harness between the rear side radar sensor (RH) and connector C-70 because the wiring harness is shorted to ground.
13		No	Replace the rear side radar sensor (RH) because there is a short to ground in the rear side radar sensor (RH). (See REAR SIDE RADAR SENSOR REMOVAL/INSTALLATION .)