LEMON Manuals: Even more car manuals for everyone
Home >> Mazda >> 2021 >> 3 Base >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Communication Devices >> On-Board Diagnostic - HS/Ms - Can >> DETERMINING SHORT TO POWER SUPPLY LOCATION (CAN-BUS No. 7) (US) >> Determination Procedure

Determination Procedure

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 terminal before performing any work that requires handling of connectors.
DETERMINING SHORT TO POWER SUPPLY LOCATION (CAN-BUS No. 7) (US) DIAGNOSTIC PROCEDURE

Step Inspection Action
1 INSPECT CAN LINE BETWEEN CONNECTOR C-49 AND BODY CONTROL MODULE (BCM) FOR SHORT TO POWER SUPPLY
Yes Go to Step 3.
No Go to the next step.
2 INSPECT BODY CONTROL MODULE (BCM) FOR SHORT TO POWER SUPPLY
Yes Replace the body control module (BCM) because there is a short to the power supply in the body control module (BCM).
(See BODY CONTROL MODULE (BCM) REMOVAL/INSTALLATION .)
No Repair or replace the wiring harness between the body control module (BCM) and connector C-49 because the wiring harness is shorted to the power supply.
3 INSPECT JB No. 2 FOR SHORT TO POWER SUPPLY
Yes Go to the next step.
No Replace the JB No. 2 because there is a short to the power supply in the JB No. 2.
4 INSPECT CAN LINE BETWEEN AUDIO AMPLIFIER AND CONNECTOR C-48 FOR SHORT TO POWER SUPPLY
  • Measure the voltage at audio amplifier terminals 2N and 2M. (With Bose® type audio)
  • Measure the voltage at audio amplifier terminals 1Q and 1S. (Without Bose® type audio)
  • Is the voltage between 1.5-3.5 V?
Yes Go to Step 6.
No Go to the next step.
5 INSPECT AUDIO AMPLIFIER FOR SHORT TO POWER SUPPLY
Yes Replace the audio amplifier because there is a short to the power supply in the audio amplifier.
(See AUDIO AMPLIFIER REMOVAL/INSTALLATION .)
No Repair or replace the wiring harness between the audio amplifier and connector C-48 because the wiring harness is shorted to the power supply.
6 INSPECT CAN LINE BETWEEN CONNECTOR C-48 AND CONNECTOR C-13 FOR SHORT TO POWER SUPPLY
Yes Go to the next step.
No Repair or replace the wiring harness between the connector C-48 and connector C-13 because the wiring harness is shorted to the power supply.
7 INSPECT CONNECTIVITY MASTER UNIT (CMU) FOR SHORT TO POWER SUPPLY
Yes Replace the connectivity master unit (CMU) because there is a short to the power supply in the connectivity master unit (CMU).
(See CONNECTIVITY MASTER UNIT (CMU) REMOVAL/INSTALLATION .)
No Repair or replace the wiring harness between the connectivity master unit (CMU) and connector C-13 because the wiring harness is shorted to the power supply.