Toyota CH-R Service Manual: Restraints Occupant Classification System Module Communication Stop Mode

Toyota CH-R Service Manual / Networking / Can Communication System / Restraints Occupant Classification System Module Communication Stop Mode

DESCRIPTION

Detection Item

Symptom

Trouble Area

Restraints Occupant Classification System Module Communication Stop Mode

Any of the following conditions are met:

  • Communication stop for "Occupant Detection" is indicated on the "Communication Bus Check" screen of the Techstream.

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  • Communication stop history for "Occupant Detection" is indicated on the "Communication Bus Check (Detail)" screen of the Techstream. (The Lost Communication Time value for "Occupant Detection" is 6 or more.)

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  • Communication system DTCs (DTCs that start with U) that correspond to "Restraints Occupant Classification System Module Communication Stop Mode" in "DTC Combination Table" are output.

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  • Occupant detection ECU branch line or connector
  • Power source circuit of occupant detection ECU
  • Occupant detection ECU ground circuit
  • Occupant detection ECU

WIRING DIAGRAM

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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  • Before measuring the resistance of the CAN bus, turn the ignition 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 (-) battery terminal and leave the vehicle for 1 minute or more before measuring the resistance.
  • After turning the ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) 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 ignition switch to ON and wait at least approximately 8 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.

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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

1.

CHECK FOR OPEN IN CAN BUS LINES (OCCUPANT DETECTION ECU BRANCH LINE)

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

(b) Disconnect the occupant detection ECU connector.

*a

Front view of wire harness connector

(to Occupant Detection ECU)

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

Y6-5 (CANH) - Y6-4 (CANL)

Cable disconnected from negative (-) battery terminal

54 to 69 Ω
NG

REPAIR OR REPLACE CAN BRANCH LINES OR CONNECTOR (OCCUPANT DETECTION ECU)
OK

2.

CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT)

(a) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

Y6-10 (GND) - Body ground

Cable disconnected from negative (-) battery terminal

Below 1 Ω

*a

Front view of wire harness connector

(to Occupant Detection ECU)

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

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

Y6-6 (IG2) - Body ground

Ignition switch ON

11 to 14 V
OK

REPLACE OCCUPANT DETECTION ECU

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)
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    DESCRIPTION There may be a short circuit between the CAN main bus lines and/or CAN branch lines when the resistance between terminals 23 (CA1H) and 8 (CA1L) of the central gateway ECU (network ga ...

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