Multiplex Communication: Overview Toyota Avalon XX30

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1. INITIALIZATION NOTE: When disconnecting the negative (-) battery cable, initialize the following system after the cable is reconnected. SYSTEM NAME AND PROCEDURE REFERENCE System Name See Procedure Power Window Control «INITIALIZATION»(ref-245121-S10087552442006102400000) Sliding Roof System «INITIALIZATION»(ref-245121-S10087552442006102400000)
2. EXPRESSIONS OF IGNITION SWITCH The type of ignition switch used on this model differs according to the specifications of the vehicle. The expressions listed in the table below are used in this article.

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DESCRIPTION

This DTC is detected when communication between the body ECU and the gateway ECU stops for more than 10 seconds.

DTC DETECTION CONDITION AND TROUBLE AREA

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1. CHECK HARNESS AND CONNECTOR (BODY ECU - BATTERY AND BODY GROUND) Disconnect the D6 ECU connector. Measure the voltage between the specified terminals on the wire harness side connector. Voltage CONNECTOR TERMINALS VOLTAGE SPECIFICATION Tester Connection Condition Specified Condition D6-2 (BATB) - Body ground Always 10 to 14 V Measure the resistance between the specified terminals on the wire harness side connector. Resistance CONNECTOR TERMINALS RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition D6-5 (GND1) - Body ground Always Below 1 ohm NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: GO TO NEXT STEP
2. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the D6, D13 and E2 ECU connectors. Measure the resistance between the specified terminals on the wire harness side connectors. Resistance CONNECTOR TERMINALS RESISTANCE SPECIFICATION Tester Connection Specified Condition D6-14 (MPX1) - E2-16 Below 1 ohm D6-21 (MPX2) - D13-6 (MPX1) Below 1 ohm Result RESULT REFERENCE Result Proceed to Both are OK A One is OK B Both are NG C B: REPLACE BODY ECU AND REPAIR OR REPLACE HARNESS OR CONNECTOR C: REPAIR OR REPLACE HARNESS OR CONNECTOR A: REPLACE BODY ECU

This DTC is detected when communication between the certification ECU and gateway ECU stops for more than 10 seconds.

DTC DETECTION CONDITION AND TROUBLE AREA

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1. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - BATTERY AND BODY GROUND) Disconnect the D39 ECU connector. Measure the voltage between the specified terminals on the wire harness side connector. Voltage CONNECTOR TERMINALS VOLTAGE SPECIFICATION Tester Connection Specified Condition D39-1 (+B1) - Body ground 10 to 14 V Measure the resistance between the specified terminals on the wire harness side connector. Resistance CONNECTOR TERMINALS RESISTANCE SPECIFICATION Tester Connection Specified Condition D39-17 (E) - Body ground Below 1 ohm NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: GO TO NEXT STEP
2. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the D13, D39 and D44 ECU connectors. Measure the resistance between the specified terminals on the wire harness side connector. Resistance CONNECTOR TERMINALS RESISTANCE SPECIFICATION Tester Connection Specified Condition D39-27 (MPX1) - D13-7 (MPX2) Below 1 ohm D39-28 (MPX2) - D44-7 (MPX1) Below 1 ohm Result RESULT REFERENCE Result Proceed to Both are OK A One is OK B Both are NG C B: REPLACE CERTIFICATION ECU AND REPAIR OR REPLACE HARNESS OR CONNECTOR C: REPAIR OR REPLACE HARNESS OR CONNECTOR A: REPLACE CERTIFICATION ECU

This DTC is detected when communication between the passenger side outer mirror ECU (memory mirror ECU) and gateway ECU stops for more than 10 seconds.

DTC DETECTION CONDITION AND TROUBLE AREA

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1. CHECK HARNESS AND CONNECTOR (MEMORY MIRROR ECU - BATTERY AND BODY GROUND) Disconnect the H1 ECU connector. Measure the voltage between the specified terminals on the wire harness side connector. Voltage CONNECTOR TERMINALS VOLTAGE SPECIFICATION Tester Connection Specified Connection H1-4 (CPUB) - Body ground 10 to 14 V Measure the resistance between the specified terminals on the wire harness side connector. Resistance CONNECTOR TERMINALS RESISTANCE SPECIFICATION Tester Connection Specified Connection H1-1 (GND) - Body ground Below 1 ohm NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: GO TO NEXT STEP
2. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the H1 and E2 ECU connectors. Measure the resistance between the specified terminals on the wire harness side connector. Resistance CONNECTOR TERMINALS RESISTANCE SPECIFICATION Tester Connection Specified Connection H1-8 (MPX1) - E2-16 Below 1 ohm NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE MEMORY MIRROR ECU

This DTC is detected when communication between the driver side outer mirror ECU (memory mirror ECU) and gateway ECU stops for more than 10 seconds.

DTC DETECTION CONDITION AND TROUBLE AREA

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1. CHECK HARNESS AND CONNECTOR (MEMORY MIRROR ECU - BATTERY AND BODY GROUND) Disconnect the I1 ECU connector. Measure the voltage between the specified terminals on the wire harness side connector. Voltage CONNECTOR TERMINALS VOLTAGE SPECIFICATION Tester Connection Specified Connection I1-4 (ECUB) - Body ground 10 to 14 V Measure the resistance between the specified terminals on the wire harness side connector. Resistance CONNECTOR TERMINALS RESISTANCE SPECIFICATION Tester Connection Specified Connection I1-1 (GND) - Body ground Below 1 ohm NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: GO TO NEXT STEP
2. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the I1 and E2 ECU connectors. Measure the resistance between the specified terminals on the wire harness side connector. Resistance CONNECTOR TERMINALS RESISTANCE SPECIFICATION Tester Connection Specified Connection I1-8 (MPX1) - E2-16 Below 1 ohm NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE MEMORY MIRROR ECU

This DTC is detected when communication between the power source control ECU and gateway ECU stops for more than 10 seconds.

DTC DETECTION CONDITION AND TROUBLE AREA

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1. CHECK HARNESS AND CONNECTOR (POWER SOURCE CONTROL ECU - BATTERY AND BODY GROUND) Disconnect the D44 ECU connector. Measure the voltage between the specified terminals on the wire harness side connector. Voltage CONNECTOR TERMINALS VOLTAGE SPECIFICATION Tester Connection Specified Condition D44-33 (AM1) - Body ground 10 to 14 V D44-12 (AM2) - Body ground 10 to 14 V Measure the resistance between the specified terminals on the wire harness side connector. Resistance CONNECTOR TERMINALS RESISTANCE SPECIFICATION Tester Connection Specified Condition D44-6 (GND2) - Body ground Below 1 ohm NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: GO TO NEXT STEP
2. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the D44, D37 and D39 ECU connectors. Measure the resistance between the specified terminals on the wire harness side connectors. Resistance CONNECTOR TERMINALS RESISTANCE SPECIFICATION Tester Connection Specified Condition D44-7 (MPX1) - D39-28 (MPX2) Below 1 ohm D44-24 (MPX2) - D37-30 (MPX+) Below 1 ohm Result RESULT REFERENCE Result Proceed to Both are OK A One is OK B Both are NG C B: REPLACE POWER SOURCE CONTROL ECU AND REPAIR OR REPLACE HARNESS OR CONNECTOR C: REPAIR OR REPLACE HARNESS OR CONNECTOR A: REPLACE POWER SOURCE CONTROL ECU

DTC B1214 is detected when the door system communication circuit and +B battery are shorted. DTC B1215 is detected when the communication circuit and body ground are shorted. When this condition is detected, the door system communication bus (BEAN) will be disabled and some diagnosis codes will be output.

DTC DETECTION CONDITION AND TROUBLE AREA

HINT

*1: w/ Smart key system

*2: w/ Driving position memory

*3: w/ Engine immobilizer w/ alarm

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1. CHECK DIAGNOSTIC TROUBLE CODE (A ECU) Disconnect the A ECU connector and check for DTCs B1214 and B1215. OK: Neither DTC B1214 nor DTC B1215 is output. NOTE: Disconnect the connectors one by one. Reconnect the connectors before starting the next check. HINT: The A ECU represents the A/C ECU. If any of the stated DTCs are not output, the disconnected A ECU (A/C ECU) is malfunctioning. NG: Go to step 2 OK: REPLACE A ECU
2. CHECK DIAGNOSTIC TROUBLE CODE (B ECU) Disconnect the A ECU and B ECU connectors and check for DTCs B1214 and B1215. OK: Neither DTC B1214 nor DTC B1215 is output. NOTE: Disconnect the connectors one by one. Reconnect the connectors before starting the next check. HINT: Remove the B ECUs in the following order: Power source ECU Certification ECU Combination switch ECU Body ECU Option connector Front controller Rain sensor Front controller Power seat ECU Memory mirror ECU (LH) Memory mirror ECU (RH) If any of the stated DTCs are not output, the disconnected B ECU (one of the ECUs from the above list) or the wire harness between the A ECU and B ECU is malfunctioning. After the DTC is cleared, proceed to the next step. NG: Go to step 4 OK: GO TO NEXT STEP
3. CHECK WIRE HARNESS BETWEEN A ECU AND B ECU Disconnect the B ECU connectors and check for DTCs B1214 and B1215. OK: Neither DTC B1214 nor DTC B1215 is output. NOTE: Disconnect the connectors one by one. Reconnect the connectors before starting the next check. HINT: If any of the stated DTCs are not output, the wire harness between the A ECU and B ECU is functioning normally but the disconnected B ECU is malfunctioning. NG: REPAIR OR REPLACE WIRE HARNESS BETWEEN A ECU AND B ECU OK: REPLACE B ECU
4. CHECK DIAGNOSTIC TROUBLE CODE (C ECU) Disconnect the B ECU and C ECU connectors and check for DTCs B1214 and B1215. OK: Neither DTC B1214 nor DTC B1215 is output. NOTE: Disconnect the connectors one by one. Reconnect the connectors before starting the next check. HINT: The C ECU represents the combination meter ECU. If any of the stated DTCs are not output, the disconnected C ECU (combination meter ECU) or the wire harness between the B ECU and C ECU is malfunctioning. NG: Go to step 6 OK: GO TO NEXT STEP
5. CHECK WIRE HARNESS BETWEEN B ECU AND C ECU Disconnect the C ECU connector and check for DTCs B1214 and B1215. OK: Neither DTC B1214 nor DTC B1215 is output. NOTE: Disconnect the connectors one by one. Reconnect the connectors before starting the next check. HINT: If any of the stated DTCs are not output, the wire harness between the B ECU and C ECU is functioning normally but the disconnected C ECU is malfunctioning. NG: REPAIR OR REPLACE WIRE HARNESS BETWEEN B ECU AND C ECU OK: REPLACE C ECU
6. CHECK WIRE HARNESS BETWEEN GATEWAY ECU AND A ECU OR C ECU Check for a short-circuit in B+ or body ground. Disconnect the A ECU, C ECU and gateway ECU connectors. Measure the voltage between the specified terminals on the wire harness side connectors. Voltage CONNECTOR TERMINALS VOLTAGE SPECIFICATION Tester Connection Specified Condition A ECU connector / gateway ECU connector - Body ground 0 V C ECU connector / gateway ECU connector - Body ground 0 V Measure the resistance between the specified terminals on the wire harness side connectors. Resistance CONNECTOR TERMINALS RESISTANCE SPECIFICATION Tester Connection Specified Condition A ECU connector / gateway ECU connector - Body ground 10 kohm or higher C ECU connector / gateway ECU connector - Body ground 10 kohm or higher HINT: The A ECU represents the A/C ECU. The C ECU represents the combination meter ECU. NG: REPAIR OR REPLACE WIRE HARNESS BETWEEN GATEWAY ECU AND A ECU OR C ECU OK: REPLACE MULTIPLEX NETWORK GATEWAY ECU

This DTC is detected when communication between the AVC-LAN (radio receiver assembly or multi-display assembly) and multiplex network gateway ECU stops for more than 10 seconds.

DTC DETECTION CONDITION AND TROUBLE AREA

This DTC is detected when communication between the A/C control (A/C ECU) and gateway ECU stops for more than 10 seconds.

DTC DETECTION CONDITION AND TROUBLE AREA

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1. CHECK HARNESS AND CONNECTOR (A/C ECU - BATTERY AND BODY GROUND) Disconnect the D37 ECU connector. Measure the voltage between the specified terminals on the wire harness side connector. Voltage CONNECTOR TERMINALS VOLTAGE SPECIFICATION Tester Connection Condition Specified Condition D37-21 (IG+) - Body ground Ignition switch OFF --> ON (IG) 0 V --> 10 to 14 V D37-1 (B) - Body ground Always 10 to 14 V Measure the resistance between the specified terminals on the wire harness side connector. Resistance CONNECTOR TERMINALS RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition D37-20 (GND) - Body ground Always Below 1 ohm NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: GO TO NEXT STEP
2. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the D37, E23, and D44 *1 or D13 *2 ECU connectors. Measure the resistance between the specified terminals on the wire harness side connectors. Resistance CONNECTOR TERMINALS RESISTANCE SPECIFICATION Tester Connection Specified Condition D37-30 (MPX+) - D44-24 (MPX2) *1 Below 1 ohm D37-30 (MPX+) - D13-7 (MPX2) *2 Below 1 ohm D37-31 (MPX-) - E23-3 (MPD1) Below 1 ohm HINT: *1 : w/ Smart key system *2 : w/o Smart key system Result RESULT REFERENCE Result Proceed to Both are OK A One is OK B Both are NG C B: REPLACE A/C ECU AND REPAIR OR REPLACE HARNESS OR CONNECTOR C: REPAIR OR REPLACE HARNESS OR CONNECTOR A: REPLACE A/C ECU

This DTC is detected when communication between the combination meter (combination meter ECU) and gateway ECU stops for more than 10 seconds.

DTC DETECTION CONDITION AND TROUBLE AREA

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1. CHECK WIRE HARNESS (COMBINATION METER ECU - BATTERY AND BODY GROUND) Disconnect the E2 meter connector. Measure the voltage between the specified terminals on the wire harness side connectors. Voltage CONNECTOR TERMINALS VOLTAGE SPECIFICATION Tester Connection Specified Condition E2-1 - Body ground 10 to 14 V E2-2 - Body ground 10 to 14 V Measure the resistance between the specified terminals on the wire harness side connectors. Resistance CONNECTOR TERMINALS RESISTANCE SPECIFICATION Tester Connection Specified Condition E2-10 - Body ground Below 1 ohm E2-12 - Body ground Below 1 ohm NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: GO TO NEXT STEP
2. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the E2, E23 and 1G ECU connectors. Measure the resistance between the specified terminals on the wire harness side connectors. Resistance CONNECTOR TERMINALS RESISTANCE SPECIFICATION Tester Condition Specified Condition E2-4 - E23-12 (MDP2) Below 1 ohm E2-16 - 1G-7 Below 1 ohm Result RESULT REFERENCE Result Proceed to Both are OK A One is OK B Both are NG C B: REPLACE COMBINATION METER ECU AND REPAIR OR REPLACE HARNESS OR CONNECTOR C: REPAIR OR REPLACE HARNESS OR CONNECTOR A: REPLACE COMBINATION METER ECU

This DTC is detected when communication between the power seat ECU and gateway ECU stops for more than 10 seconds.

DTC DETECTION CONDITION AND TROUBLE AREA

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1. CHECK HARNESS AND CONNECTOR (POWER SEAT ECU - BATTERY AND BODY GROUND) Disconnect the Q14 and Q15 ECU connectors. Measure the voltage between the specified terminals on the wire harness side connector. Voltage CONNECTOR TERMINALS VOLTAGE SPECIFICATION Tester Connection Specified Condition Q14-8 (SYSB) - Body ground 10 to 14 V Q15-5 (+B) - Body ground 10 to 14 V Measure the resistance between the specified terminals on the wire harness side connector Resistance CONNECTOR TERMINALS RESISTANCE SPECIFICATION Tester Connection Specified Condition Q15-1 (GND) - Body ground Below 1 ohm NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: GO TO NEXT STEP
2. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the Q14 and H1 ECU connectors. Measure the resistance between the specified terminals on the wire harness side connector. Resistance CONNECTOR TERMINALS RESISTANCE SPECIFICATION Tester Connection Specified Condition Q14-1 (MPX1) - H1-8 (MPX1) Below 1 ohm NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE POWER SEAT ECU

This DTC is detected when communication between the BEAN bus buffer and the gateway ECU stops for more than 10 seconds.

DTC DETECTION CONDITION AND TROUBLE AREA

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1. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the D16, D7 and IR connectors. Measure the resistance between the specified terminals on the wire harness side connectors. Resistance CONNECTOR TERMINALS RESISTANCE SPECIFICATION Tester Connection Specified Condition D16-1 (MPX+) - IR-9 Below 1 ohm D16-2 (GBSI) - D7-14 (GBS) Below 1 ohm Result RESULT REFERENCE Result Proceed to Both are OK A One is OK B Both are NG C B: REPLACE OPTION CONNECTOR AND REPAIR OR REPLACE HARNESS OR CONNECTOR C: REPAIR OR REPLACE HARNESS OR CONNECTOR A: REPLACE OPTION CONNECTOR

This DTC is detected when communication between the combination switch (combination switch ECU) and gateway ECU stops for more than 10 seconds.

DTC DETECTION CONDITION AND TROUBLE AREA

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1. CHECK HARNESS AND CONNECTOR (COMBINATION SWITCH - BATTERY AND BODY GROUND) Disconnect the D13 combination switch connector. Measure the voltage between the specified terminals on the wire harness side connector. Voltage CONNECTOR TERMINALS VOLTAGE SPECIFICATION Tester Connection Condition Specified Condition D13-1 (B) - Body ground Always 10 to 14 V D13-2 (IG) - Body ground Ignition switch OFF --> ON (IG) 0 V --> 10 to 14 V Measure the resistance between the specified terminals on the wire harness side connector. Resistance CONNECTOR TERMINALS RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition D13-5 (E) - Body ground Always Below 1 ohm NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: GO TO NEXT STEP
2. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the D13, D6, and D39 *1 or D37 *2 ECU connectors. Measure the resistance between the specified terminals on the wire harness side connectors. Resistance CONNECTOR TERMINALS RESISTANCE SPECIFICATION Tester Connection Specified Condition D13-6 (MPX1) - D6-21 (MPX2) Below 1 ohm D13-7 (MPX2) - D39-27 (MPX1) *1 Below 1 ohm D13-7 (MPX2) - D37-30 (MPX+) *2 Below 1 ohm HINT: *1 : w/ Smart key system *2 : w/o Smart key system Result RESULT REFERENCE Result Proceed to Both are OK A One is OK B Both are NG C B: REPLACE COMBINATION SWITCH AND REPAIR OR REPLACE HARNESS OR CONNECTOR C: REPAIR OR REPLACE HARNESS OR CONNECTOR A: REPLACE COMBINATION SWITCH ECU

This DTC is detected when communication between the rain sensor and overhead J/B stops for more than 10 seconds.

DTC DETECTION CONDITION AND TROUBLE AREA

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1. CHECK WIRE HARNESS (RAIN SENSOR - BATTERY AND BODY GROUND) Disconnect the O3 sensor connector. Measure the voltage between the specified terminals on the wire harness side connector. Voltage CONNECTOR TERMINALS VOLTAGE SPECIFICATION Tester Connection Condition Specified Condition O3-1 (SIG) - Body ground Always 10 to 14 V Measure the resistance between the specified terminals on the wire harness side connector. Resistance CONNECTOR TERMINALS RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition O3-3 (ES) - Body ground Always Below 1 ohm NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: GO TO NEXT STEP
2. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the O3 and IR ECU connectors. Measure the resistance between the specified terminals on the wire harness side connector. Resistance CONNECTOR TERMINALS RESISTANCE SPECIFICATION Tester Connection Specified Condition O3-2 (MPX) - IR-9 Below 1 ohm NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE RAIN SENSOR

This DTC is detected when communication between the front controller and gateway ECU stops for more than 10 seconds.

DTC DETECTION CONDITION AND TROUBLE AREA

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1. CHECK HARNESS AND CONNECTOR (FRONT CONTROLLER - BATTERY AND BODY GROUND) Disconnect the 1F and 1H front controller connectors. Measure the voltage between the specified terminals on the wire harness side connector. Voltage CONNECTOR TERMINALS VOLTAGE SPECIFICATION Tester Connection Condition Specified Condition 1F-1 (+B) - Body ground Always 10 to 14 V Measure the resistance between the specified terminals on the wire harness side connector. Resistance CONNECTOR TERMINALS RESISTANCE SPECIFICATION Tester Connection Condition Specified Condition 1H-2 (GND) - Body ground Always Below 1 ohm NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: GO TO NEXT STEP
2. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the 1G, 1R, and E2 connectors. Measure the resistance between the specified terminals on the wire harness side connector. Resistance CONNECTOR TERMINALS RESISTANCE SPECIFICATION Tester Connection Specified Condition 1G-7 (MPX) - E2-16 Below 1 ohm 1G-8 (MPX) - 1R-9 (MPX1) Below 1 ohm NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE FRONT CONTROLLER