Toyota Avalon (XX50) 2019-2022 Service & Repair Manual: Electric Parking Brake ECU Communication Stop Mode

DESCRIPTION

WIRING DIAGRAM

CAUTION / NOTICE / HINT

CAUTION:

When performing the confirmation driving pattern, obey all speed limits and traffic laws.

NOTICE:

• Because the order of diagnosis is important to allow correct diagnosis, make sure to begin troubleshooting using How to Proceed with Troubleshooting when CAN communication system related DTCs are output.

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• Before measuring the resistance of the CAN bus, turn the power switch off and leave the vehicle for 1 minute or more without operating the key or any switches, or opening or closing the doors. After that, disconnect the cable from the negative (-) auxiliary battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.
• After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.

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• After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.

  DTC check procedure: Turn the power switch on (IG) and wait for 1 minute or more. Then operate the suspected malfunctioning system and drive the vehicle at 60 km/h (37 mph) or more for 5 minutes or more.

• After the repair, perform the CAN bus check and check that all the ECUs and sensors connected to the CAN communication system are displayed as normal.

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• Inspect the fuses for circuits related to this system before performing the following procedure.

HINT:

• Before disconnecting related connectors for inspection, push in on each connector body to check that the connector is not loose or disconnected.
• When a connector is disconnected, check that the terminals and connector body are not cracked, deformed or corroded.

PROCEDURE

(a) Disconnect the cable from the negative (-) auxiliary battery terminal.

(b) Disconnect the A39 brake actuator assembly connector.

(c) Measure the resistance according to the value(s) in the table below. Standard Resistance: Tester Connection Condition Specified Condition A39-12 (CANH) - A39-11 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω

*a Front view of wire harness connector (to Brake Actuator Assembly)

NG

REPAIR OR REPLACE CAN BRANCH LINES OR CONNECTOR (BRAKE ACTUATOR ASSEMBLY)

OK

(a) Measure the resistance according to the value(s) in the table below. Standard Resistance: Tester Connection Condition Specified Condition A39-1 (MGND) - Body ground Cable disconnected from negative (-) auxiliary battery terminal Below 1 Ω A39-2 (EGND) - Body ground Cable disconnected from negative (-) auxiliary battery terminal Below 1 Ω

*a Front view of wire harness connector (to Brake Actuator Assembly)

(b) Reconnect the cable to the negative (-) auxiliary battery terminal.

(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

OK

REPLACE BRAKE ACTUATOR ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)