Multiplex Communication: Overview Toyota 4Runner IV рестайлинг

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1. MULTIPLEX COMMUNICATION SYSTEM (BEAN) DESCRIPTION The BEAN communication line is used to control the following items: Instrument panel junction block assembly (Body ECU) Theft warning ECU assembly (Theft deterrent ECU) Multiplex network door ECU back (Back door ECU) If there is a short-circuit (bus-down) in the line, communication to the system that had a short-circuit (bus-down) will be disabled and the DTC concerning the system will be output from the multiplex network body ECU.

DESCRIPTION

B1214 and B1215 are output when +B and the body ground is short-circuited on the communication bus. Detecting this condition disables all the BEAN communication and outputs some DTCs.

DIAGNOSTIC TROUBLE CODE CHART

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1. CHECK DIAGNOSTIC TROUBLE CODE (A ECU) Check whether the output of the DTC stops when the A ECU connector is disconnected. NOTE: Disconnect the connectors in the operational sequence, and start the next step after the connector in connected. HINT: In this case, the A ECU in the represents the back door ECU. OK: When the output of the DTC stops, the disconnected A ECU is abnormal. OK: REPLACE A ECU NG: Go to next step.
2. CHECK DIAGNOSTIC TROUBLE CODE (B ECU) Check whether the output of the DTC stops when the B ECU connector is disconnected. OK: Neither DTC B1214 nor DTC B1215 is output. NOTE: Disconnect the connectors in the operational sequence, and start the next step after the connector in connected. HINT: In this case, the B ECU in the represents the theft deterrent ECU. OK: When the output of the DTC stops, the disconnected B ECU is abnormal. OK: REPLACE B ECU NG: Go to next step.
3. CHECK WIRE HARNESS BETWEEN BODY ECU AND A ECU OR B ECU Disconnect the A ECU, B ECU and body ECU connectors. Check the wire harness (MPX line) between the A ECU, B ECU and body ECU. Turn the ignition switch ON. Check the voltage between the wire harness (MPX line) and body ground. Standard voltage WIRE HARNESS BETWEEN BODY ECU AND A ECU OR B ECU VOLTAGE MPX line - Body ground Specified Condition Body ECU or A ECU (Back door ECU) - Body ground Below 1 V Body ECU or B ECU (Theft deterrent ECU) - Body ground Below 1 V If the output voltage is not Below 1V, the wire harness (MPX line) may be short-circuited with +B. Check the resistance of the wire harness (MPX lines) and body ground. Standard resistance WIRE HARNESS BETWEEN BODY ECU AND A ECU OR B ECU RESISTANCE MPX line - Body ground Specified Condition Body ECU or A ECU (Back door ECU) - Body ground 10 kohms or higher Body ECU or B ECU (Theft deterrent ECU) - Body ground 10 kohms or higher If there is Below 1 ohms, the wire harness (MPX line) and body ground may be short-circuited with the body ground. NG: REPAIR OR REPLACE WIRE HARNESS BETWEEN BODY ECU AND A ECU OR B ECU OK: REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

DTC B1269 is output when the communication between the theft deterrent ECU and the body ECU stops for more than 10 seconds.

DTC DETECTION CONDITION CHART

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1. CHECK WIRE HARNESS (BODY ECU - THEFT DETERRENT ECU) Check the wire harness between the body ECU and theft deterrent ECU. Disconnect the B6 and T5 connectors. Measure the resistance of the wire harness side connector. Standard resistance WIRE HARNESS (BODY ECU - THEFT DETERRENT ECU) Tester Connection Condition Specified Condition MPX3 (B6-26) - MPX1 (T5-31) Always Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step.
2. INSPECT THEFT WARNING ECU ASSEMBLY Disconnect the T5 connector. Measure the voltage of the wire harness side connector. Standard voltage THEFT WARNING ECU ASSEMBLY Tester Connection Condition Specified Condition +B1 (T5-2) - Body ground Always 10 to 14 V +B2 (T5-3) > Body ground Always 10 to 14 V NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step.
3. INSPECT THEFT WARNING ECU ASSEMBLY Disconnect the T5 connector. Measure the resistance of the wire harness side connector. Standard resistance THEFT WARNING ECU ASSEMBLY Tester Connection Condition Specified Condition E (T5-29) - Body ground Always Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE THEFT WARNING ECU ASSEMBLY

B1287 is output when the communication between the multiplex network door ECU back (back door ECU) and multiplex network body ECU stops for more than 10 seconds.

DTC DETECTION CONDITION CHART

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1. CHECK WIRE HARNESS (BODY ECU - BACK DOOR ECU) Check the wire harness between the body ECU and back door ECU. Disconnect the B4 and B8 connectors. Measure the resistance of the wire harness side connector. Standard resistance WIRE HARNESS (BODY ECU - BACK DOOR ECU) Tester Connection Condition Specified Condition MPX2 (84-23) - MPX2 (B8-1) Always Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step.
2. INSPECT MULTIPLEX NETWORK DOOR ECU (BACK DOOR ECU) Disconnect the B8 connector. Measure the voltage of the wire harness side connector. Standard voltage MULTIPLEX NETWORK DOOR ECU (BACK DOOR ECU) Tester Connection Condition Specified Condition BECU (B8-5) - Body ground Always 10 to 14 V BDR (B8-4) - Body ground Always 10 to 14 V NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step.
3. INSPECT MULTIPLEX NETWORK DOOR ECU (BACK DOOR ECU) Disconnect the B8 connector. Measure the resistance of the wire harness side connector. Standard resistance MULTIPLEX NETWORK DOOR ECU (BACK DOOR ECU) Tester Connection Condition Specified Condition GND (B8-3) - Body ground Always Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE MULTIPLEX NETWORK DOOR ECU (BACK DOOR ECU)