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Home >> Mazda >> 2021 >> 3 Base >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Communication Devices >> On-Board Diagnostic - HS/Ms - Can >> DETERMINING SHORT BETWEEN CIRCUITS LOCATION (CAN-BUS No. 8) (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 BETWEEN CIRCUITS LOCATION (CAN-BUS No. 8) (US) DIAGNOSTIC PROCEDURE

Step Inspection Action
1 INSPECT BODY CONTROL MODULE (BCM) FOR SHORT BETWEEN CIRCUITS
Yes Go to the next step.
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 .)
2 INSPECT TELEMATICS COMMUNICATION UNIT FOR SHORT BETWEEN CIRCUITS
  • Switch the ignition off.
  • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .)
  • Disconnect the telematics communication unit connector.
  • Inspect for continuity between telematics communication unit terminals 1Q and 1S (wiring harness side).
  • Is there continuity?
Yes Repair or replace the wiring harness between telematics communication unit and body control module (BCM) because the wiring harness is shorted between circuits.
No Replace the telematics communication unit because there is a short between circuits in the telematics communication unit.
(See TELEMATICS COMMUNICATION UNIT REMOVAL/INSTALLATION .)