Toyota CH-R Service Manual: Open in One Side of Bus 3 Branch Line

Toyota CH-R Service Manual / Networking / Can Communication System / Open in One Side of Bus 3 Branch Line

DESCRIPTION

When the CAN bus main lines are normal (no open, short to ground, short to +B or short between lines) and there is an ECU or sensor on the "Communication Bus Check" screen that is indicated as not communicating or whose connection status on the "Communication Bus Check" screen changes intermittently, an open in one of the wires of a CAN bus branch line is suspected.

HINT:

If there is an ECU or sensor whose connection status changes intermittently while checking the "Communication Bus Check" screen, there may be an open circuit in one of the wires of a branch line of an ECU or sensor in the bus. If an open occurs in one of the wires of a CAN branch line, it may interfere with the communication of other ECUs or sensors resulting in an incorrect state being displayed.

Symptom	Trouble Area
There is an ECU or sensor that is indicated as not communicating on the "Communication Bus Check" screen or whose connection status on the "Communication Bus Check" screen changes intermittently.	One side of CAN branch line is open, or output signals are incomplete. Radio and display receiver assembly (for Radio and Display Type) DCM (Telematics transceiver) (w/ Telematics Transceiver)

CAUTION / NOTICE / HINT

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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After performing repairs, perform the DTC check procedure and confirm that the DTCs are not output again.
DTC check procedure: Turn the ignition switch ON and wait at least approximately 60 seconds.
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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PROCEDURE

1.	CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH LINE

(a) Based on the vehicle equipment and specifications, confirm the systems that use CAN communication.

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(b) Connect the Techstream to the DLC3.

(d) Turn the Techstream on.

(e) Using the Techstream, perform "CAN Bus Check".

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CAN Bus Check

(f) Observe the screen for approximately 2 minutes to check for ECUs and sensors that are displayed as not communicating.

(g) Perform the inspection as specified in the Problem Symptoms Table for the ECUs or sensors that are not communicating.

GO TO CORRESPONDING COMMUNICATION STOP MODE

Check Bus 3 Line for Short to GND

DESCRIPTION There may be a short circuit between one of the CAN bus lines and GND when there is no resistance between terminal 6 (CA3H) of the central gateway ECU (network gateway ECU) and termin ...

Check Bus 4 Lines for Short Circuit

DESCRIPTION There may be a short circuit between the CAN main bus lines and/or CAN branch lines when the resistance between terminals 22 (CA2H) and 7 (CA2L) of the central gateway ECU (network ga ...

Other materials:

Toyota CH-R Service Manual > Can Communication System: Data List / Active Test
DATA LIST / ACTIVE TEST NOTICE: In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not. HINT: Using the Techstream to read the Data List allows the values or s ...

Toyota CH-R Service Manual > Theft Deterrent System: Security Horn Circuit
DESCRIPTION When the theft deterrent system is switched from the armed state to the alarm sounding state, the main body ECU (multiplex network body ECU) transmits a signal to cause the security horn assembly to sound at intervals of 0.4 seconds. WIRING DIAGRAM CAUTION / NOTICE / HINT NO ...

Toyota CH-R Service Manual: Open in One Side of Bus 3 Branch Line

Check Bus 3 Line for Short to GND

Check Bus 4 Lines for Short Circuit

Other materials:

Toyota C-HR (AX20) 2023-2025 Owner's Manual

Toyota CH-R Owners Manual

Toyota CH-R Service Manual