Multiplex Communication: Diagnosis Lexus RX II рестайлинг

HOW TO PROCEED WITH TROUBLESHOOTING

HINT

1. Use this procedure to troubleshoot the multiplex communication system.
2. The intelligent tester should be used in step 2 .

1. VEHICLE BROUGHT TO WORKSHOP
2. CHECK FOR DTC Check for DTCs and note any codes that are output. Delete the DTC. Recheck for DTCs. Try to prompt the DTC by simulating the original activity that the DTC suggests. Result RESULT CHART Result Proceed to DTC does not reoccur A DTC reoccurs B B: GO TO step 4 A: Go to next step
3. OVERALL ANALYSIS AND TROUBLESHOOTING (See «TERMINALS OF ECU»(ref-282977-S37197018662008041400000) ).
4. ADJUST, REPAIR OR REPLACE
5. CONFIRMATION TEST NEXT: END

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1. CHECK MULTIPLEX NETWORK GATEWAY ECU Disconnect the G3 ECU connector. Measure the voltage and resistance of the wire harness side connector. TERMINALS VOLTAGE CHART Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition BATT (G3-10) - GND (G3 24) SB - W-B +B (BATT) power supply Always 10 to 14 V IG (G3-1) - Body ground Y - Body ground Ignition power supply Ignition switch ON 10 to 14 V ACC (G3-2) - Body ground L - Body ground ACC power supply Ignition switch ON 10 to 14 V SIL (G3-7) - Body ground GR - Body ground Bus "+" line During transmission Pulse generation MPI1 (G3-4) - Body ground GR - Body ground MPX line Always 10 kohms or higher MPI2 (G3-13) - Body ground O - Body ground MPX line Always 10 kohms or higher MPD1 (G3-3) - Body ground R - Body ground MPX line Always 10 kohms or higher MPD2 (G3-12) - Body ground L (1) - Body ground R (2) - Body ground W-B - Body ground Always 10 kohms or higher GND (G3-24) - Body ground W-B - Body ground Ground Always Below 1 ohms GTX- (G3-21) - Body ground B - Body ground AVC-LAN line Always 10 kohms or higher GTX+ (G3-6) - Body ground R - Body ground AVC-LAN line Always 10 kohms or higher (1) with Tire Pressure Warning System (2) without Tire Pressure Warning System If the result is not as specified, there may be a malfunction on the wire harness side.
2. CHECK INSTRUMENT PANEL JUNCTION BLOCK (MULTIPLEX NETWORK BODY ECU) Disconnect the 1E, 1D and 1F junction block connectors. Disconnect the B5 ECU connector. Measure the resistance and voltage of the wire harness side connectors. TERMINALS VOLTAGE CHART Symbols (Terminals No.) Wiring Color Terminal Description Condition Specified Condition BECU (1D-10) - Body ground W - Body ground +B (BECU) power supply Always 10 to 14 V MPX1 (1E-7) - Body ground BR - Body ground MPX line Always 10 kohms or higher MPX2 (B5-21) - Body ground O - Body ground MPX line Always 10 kohms or higher GND1 (1F-10) - Body ground W-B - Body ground Ground Always Below 1 ohms If the result is not as specified, there may be a malfunction on the wire harness side.
3. CHECK CENTER CLUSTER INTEGRATION PANEL (W/O LEXUS NAVIGATION SYSTEM) Disconnect the C4 panel connector. Measure the voltage and resistance of the wire harness side connector. TERMINALS VOLTAGE CHART Symbols (Terminals No.) Wiring Color Terminal Description Condition Specified Condition IG+ (C4-9) - Body ground LG - Body ground Ignition switch (on) signal Ignition switch ON 10 to 14 V MPX+ (C4-5) - Body ground L - Body ground MPX line Always 10 kohms or higher MPX- (C4-12) - Body ground R - Body ground MPX line Always 10 kohms or higher GND (C4-7) - Body ground W-B - Body ground Ground Always Below 1 ohms If the result is not as specified, there may be a malfunction on the wire harness side.
4. CHECK AUTO WIPER ECU Disconnect the A28 and A29 ECU connectors. Measure the voltage and resistance of the wire harness side connector. TERMINALS VOLTAGE CHART Symbols (Terminals No.) Wiring Color Terminal Description Condition Specified Condition WIG (A29-10) - Body ground Y - Body ground Ignition switch (on) signal Ignition switch ON 10 to 14 V MPX1 (A28-1) - Body ground BR - Body ground MPX line Always 10 kohms or higher E (A28-12) - Body ground W-B - Body ground Ground Always Below 1 ohms If the result is not as specified, there may be a malfunction on the wire harness side.
5. CHECK AFS ECU (W/ ADAPTIVE FRONT-LIGHT SYSTEM) Disconnect the A14 ECU connector. Measure the voltage and the resistance of the wire harness side connector. TERMINALS VOLTAGE CHART Symbols (Terminals No.) Wiring Color Terminal Description Condition Specified Condition IG (A14-2) - Body ground P - Body ground Ignition switch (on) signal Ignition switch ON 10 to 14 V IGS (A14-12) - Body ground P - Body ground Ignition switch (on) signal Ignition switch ON 10 to 14 V MPX1 (A14-5) - Body ground P - Body ground MPX line Always 10 kohms or higher E1 (A14-1) - Body ground W-B - Body ground Ground Always Below 1 ohms If the result is not as specified, there may be a malfunction on the wire harness side.
6. CHECK POSITION CONTROL ECU AND SWITCH ASSEMBLY (W/ DRIVING POSITION MEMORY) Disconnect the P32 and P33 ECU connectors. Measure the voltage and the resistance of the wire harness side connector. TERMINALS VOLTAGE CHART Symbols (Terminals No.) Wiring Color Terminal Description Condition Specified Condition +B (P33-5) - Body ground LG - Body ground +B (+B) power supply Always 10 to 14 V MPX1 (P32-1) - Body ground W - Body ground MPX line Always 10 kohms or higher GND (P33-1) - Body ground W-B - Body ground Ground Always Below 1 ohms If the result is not as specified, there may be a malfunction on the wire harness side.
7. CHECK AIR CONDITIONING AMPLIFIER (A/C ECU) Disconnect the A8 amplifier connector. Measure the voltage and resistance of the wire harness side connector. TERMINALS VOLTAGE CHART Symbols (Terminals No.) Wiring Color Terminal Description Condition Specified Condition IG+ (A8-1) - Body ground Y - Body ground Ignition switch (on) signal Ignition switch ON 10 to 14 V MPX+ (A8-3) - Body ground BR - Body ground MPX line Always 10 kohms or higher MPX- (A8-4) - Body ground GR - Body ground MPX line Always 10 kohms or higher GND (A8-6) - Body ground W-B - Body ground Ground Always Below 1 ohms If the result is not as specified, there may be a malfunction on the wire harness side.
8. CHECK CENTER AIRBAG SENSOR ASSEMBLY Disconnect the A20 sensor connector. Measure the voltage and resistance of the wire harness side connector. TERMINALS VOLTAGE CHART Symbols (Terminals No.) Wiring Color Terminal Description Condition Specified Condition IG2 (A20-5) - Body ground B - Body ground Ignition switch (on) signal Ignition switch ON 10 to 14 V MPX1 (A20-24) - Body ground BR - Body ground MPX line Always 10 kohms or higher MPX2 (A20-22) - Body ground BR - Body ground MPX line Always 10 kohms or higher E2 (A20-28) - Body ground W-B - Body ground Ground Always Below 1 ohms If the result is not as specified, there may be a malfunction on the wire harness side.
9. CHECK COMBINATION METER ASSEMBLY (METER ECU) Disconnect the C8 and C9 meter connectors. Measure the voltage and resistance of the wire harness side connector. TERMINALS VOLTAGE CHART Symbols (Terminals No.) Wiring Color Terminal Description Condition Specified Condition B (C8-15) - Body ground SB - Body ground +B (B) power supply Always 10 to 14 V B (C8-16) - Body ground O - Body ground +B (B) power supply Always 10 to 14 V MPX+ (C9-4) - Body ground V - Body ground MPX line Always 10 kohms or higher MPX- (C8-5) - Body ground Y - Body ground MPX line Always 10 kohms or higher E (C9-1) - Body ground W-B - Body ground Ground Always Below 1 ohms If the result is not as specified, there may be a malfunction on the wire harness side.
10. CHECK SLIDING ROOF DRIVE GEAR (SLIDING ROOF CONTROL ECU) Disconnect the M12 driver gear connector. Measure the voltage and the resistance of the wire harness side connector. TERMINALS VOLTAGE CHART Symbols (Terminals No.) Wiring Color Terminal Description Condition Specified Condition B (M12-1) - Body ground P - Body ground +B (B) power supply Always 10 to 14 V MPX1 (M12-10) - Body ground R - Body ground MPX line Always 10 kohms or higher E (M12-7) - Body ground W-B - Body ground Ground Always Below 1 ohms If the result is not as specified, there may be a malfunction on the wire harness side.
11. CHECK MULTIPLEX TILT AND TELESCOPIC ECU (W/ DRIVING POSITION MEMORY) Disconnect the T4 ECU connector. Measure the voltage and resistance of the wire harness side connector. TERMINALS VOLTAGE CHART Symbols (Terminals No.) Wiring Color Terminal Description Condition Specified Condition +B (T4-2) - Body ground Y - Body ground +B (+B) power supply Always 10 to 14 V MPX1 (T4-5) - Body ground GR - Body ground MPX line Always 10 kohms or higher MPX2 (T4-14) - Body ground O - Body ground MPX line Always 10 kohms or higher GND (T4-11) - Body ground W-B - Body ground Ground Always Below 1 ohms If the result is not as specified, there may be a malfunction on the wire harness side.
12. CHECK RAIN SENSOR Disconnect the R7 sensor connector. Measure the voltage and resistance of the wire harness side connector. TERMINALS VOLTAGE CHART Symbols (Terminals No.) Wiring Color Terminal Description Condition Specified Condition SIG (R7-1) - Body ground P (1) - Body ground B (2) - Body ground Ignition switch (on) signal Ignition switch ON 10 to 14 V MPX (R7-2) - Body ground V - Body ground MPX line Always 10 kohms or higher ES (R7-3) - Body ground W-B - Body ground Ground Always Below 1 ohms (1) with Sliding Roof (2) without Sliding Roof If the result is not as specified, there may be a malfunction on the wire harness side.
13. CHECK MULTIPLEX NETWORK MASTER SWITCH Disconnect the P22 switch connector. Measure the voltage and resistance of the wire harness side connector. TERMINALS VOLTAGE CHART Symbols (Terminals No.) Wiring Color Terminal Description Condition Specified Condition CPUB (P22-9) - Body ground L-B - Body ground +B (CPUB) power supply Always 10 to 14 V GND (P22-2) - Body ground W-B - Body ground Ground Always Below 1 ohms MPX1 (P22-7) - Body ground R - Body ground MPX line Always 10kohms or higher MPX2 (P22-8) - Body ground GR - Body ground MPX line Always 10 kohms or higher If the result is not as specified, there may be a malfunction on the wire harness side.
14. CHECK MULTIPLEX BACK DOOR ECU Disconnect the P13 and P14 ECU connectors. Measure the voltage and resistance of the wire harness side connector. TERMINALS VOLTAGE CHART Symbols (Terminals No.) Wiring Color Terminal Description Condition Specified Condition B (P14-2) - Body ground Y - Body ground +B (B) power supply Always 10 to 14 V MPX1 (P13-22) - Body ground W - Body ground MPX line Always 10 kohms or higher GND (P14-8) - Body ground W-B - Body ground Ground Always Below 1 ohms If the result is not as specified, there may be a malfunction on the wire harness side.
15. CHECK TRANSPONDER KEY ECU Disconnect the T9 ECU connector. Measure the resistance and voltage of the wire harness side connector. TERMINALS VOLTAGE CHART Symbols (Terminals No.) Wiring Color Terminal Description Condition Specified Condition CPUB (T9-1) - Body ground V - Body ground B (CPUB) power supply Always 10 to 14 V MPX1 (T9-4) - Body ground O - Body ground MPX line Always 10 kohms or higher MPX2 (T9-5) - Body ground R - Body ground MPX line Always 10 kohms or higher GND (T9-14 ) - Body ground W-B - Body ground Ground Always Below 1 ohms If the result is not as specified, there may be a malfunction on the wire harness side.
16. CHECK OUTER MIRROR CONTROL ECU LH Disconnect the R27 ECU connector. Measure the resistance and voltage of the wire harness side connector. TERMINALS VOLTAGE CHART Symbols (Terminals No.) Wiring Color Terminal Description Condition Specified Condition CPUB (R27-7) - Body ground L-B - Body ground B (CPUB) power supply Always 10 to 14 V MPX1 (R27-6) - GND (R27-1) R-W-B MPX line Always 10 kohms or higher GND (R27-1 ) - Body ground W-B - Body ground Ground Always Below 1 ohms If the result is not as specified, there may be a malfunction on the wire harness side.
17. CHECK OUTER MIRROR CONTROL ECU RH Disconnect the R28 ECU connector. Measure the resistance and voltage of the wire harness side connector. TERMINALS VOLTAGE CHART Symbols (Terminals No.) Wiring Color Terminal Description Condition Specified Condition CPUB (R28-7) - Body ground L-B - Body ground B (CPUB) power supply Always 10 to 14 V MPX1 (R28-6) - GND (R28-1) L-W-B MPX line Always 10 kohms or higher GND (R28-1 ) - Body ground W-B - Body ground Ground Always Below 1 ohms If the result is not as specified, there may be a malfunction on the wire harness side.
18. CHECK TIRE PRESSURE WARNING ECU Disconnect the T23 ECU connector. Measure the resistance and voltage of the wire harness side connector. TERMINALS VOLTAGE CHART Symbols (Terminals No.) Wiring Color Terminal Description Condition Specified Condition IG (T23-1) - GND (T23-7) Y-W-B Ignition switch (on) signal Ignition switch ON 10 to 14 V MPX1 (T23-6) - GND (T23-7) R-W-B MPX line Always 10 kohms or higher GND (T23-7) - Body ground W-B - Body ground Ground Always Below 1 ohms MPX2 (T23-12) - GND (T23-7) L-W-B MPX line Always 10 kohms or higher If the result is not as specified, there may be a malfunction on the wire harness side.

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1. CHECK DLC3 The vehicle's ECU uses the ISO 15765-4 for communication. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 15765-4 format. DLC3 CONNECTOR TERMINALS CHART Symbol (Terminal No.) Terminal Description Condition Specified Condition SIL (7) - SG (5) Bus "+" line During transmission Pulse generation CG (4) - Body ground Chassis ground Always Below 1 ohms SG (5) - Body ground Signal ground Always Below 1 ohms BAT (16) - Body ground Battery positive Always 10 to 14 V CANH (6) - CANL (14) CAN bus line Ignition switch Lock (1) 54 to 69 ohms CANH (6) - BAT (16) HIGH-level CAN bus line Ignition switch Lock (1) 6 kohms or higher CANH (6) - CG (4) HIGH-level CAN bus line Ignition switch Lock (1) 200 ohms or higher CANL (14) - BAT (16) LOW-level CAN bus line Ignition switch Lock (1) 6 kohms or higher CANL (14) - CG (4) LOW-level CAN bus line Ignition switch Lock (1) 200 ohms or higher NOTE: (1) Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the ignition switch, any other switches, or the doors. HINT: Connect the cable of the intelligent tester to the DLC3, turn the ignition switch to the ON position and attempt to use the tester. If the display indicates that a communication error has occurred, there is a problem either with the vehicle or with the tester. If communication is normal when the tester is connected to another vehicle, inspect the DLC3 of the original vehicle. If communication is still not possible when the tester is connected to another vehicle, the problem may be in the tester itself. Consult the Service Department listed in the tester's instruction manual.

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1. CHECK DTC Connect the intelligent tester to the DLC3. Turn the ignition switch to the ON position. Enter the following menus: DIAGNOSIS / OBD/ MOBD / BODY / DTC INFO. Check the DTCs on the tester screen. HINT: Refer to the intelligent tester operator's manual for further details.
2. CLEAR DTC Connect the intelligent tester to the DLC3. Turn the ignition switch to the ON position. Erase the DTCs by following the prompts on the tester screen. Enter the following menus: DIAGNOSIS / OBD/ MOBD / BODY / DTC INFO. HINT: Refer to the intelligent tester operator's manual for further details.

DIAGNOSTIC TROUBLE CODE CHART

If malfunction code is displayed during DTC check, check the circuit corresponding to the code in the table below. Proceed to the page given for the circuit.

MULTIPLEX COMMUNICATION SYSTEM

DIAGNOSTIC TROUBLE CODE CHART

When "+B or GND short malfunction of communication bus" DTCs (B1214 and B1215) are detected at the same time as "communication stop" DTCs (B1200, B1205, B1206, B1208, B1209, B1213, B1247, B1272, B1287 and B1294), please repair the "+B or GND short malfunction of communication bus" DTCs first.

When "+B or GND short malfunction of communication bus" DTCs (B1266 and B1267) are detected at the same time as "communication stop" DTCs (B1245, B1262, B1271, B1273, B1277, B1279 and B1281), please repair the "+B or GND short malfunction of communication bus" DTCs first.

INSPECTION PROCEDURE

HINT

When "+B or GND short malfunction of communication bus" DTCs (B1214 and B1215) are detected at the same time as "communication stop" DTC B1200, repair the "+B or GND short malfunction of communication bus" DTCs first.

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1. CHECK OPERATION Check if the wireless door lock control function operates normally through the wireless transmitter. HINT: With this inspection, the multiplex network body ECU CPU can be diagnosed if it works normally or not. OK: Wireless door lock function operates normally. OK: GO TO step 4 NG: Go to next step
2. INSPECT FUSE (EUC-B NO. 1) Remove the ECU-B No. 1 fuse from the fusible link block. Measure the resistance of the fuse. Standard resistance: Below 1 ohms NG: REPLACE FUSE OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (MULTIPLEX NETWORK BODY ECU - BATTERY AND BODY GROUND) Disconnect the 1D and 1F instrument panel junction block connectors. Measure the resistance and voltage of the wire harness side connectors. Standard voltage TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition 1D-10 (BECU) - Body ground 10 to 14 V Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition 1F-10 (GND1) - Body ground Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the 1E fusible link block connector. Disconnect the B5 and T9 ECU connectors. Disconnect the P22 switch connector. Measure the resistance of the wire harness side connectors. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition 1E-7 (MPX1) - P22-8 (MPX2) Below 1 ohms B5-21 (MPX2) - T9-4 (MPX1) Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE INSTRUMENT PANEL JUNCTION BLOCK (MULTIPLEX NETWORK BODY ECU)

HINT

When "+B or GND short malfunction of communication bus" DTCs (B1214 and B1215) are detected at the same time as "communication stop" DTC B1205, repair the "+B or GND short malfunction of communication bus" DTCs first.

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1. INSPECT FUSE (ECU-IG NO. 2) Remove the ECU-IG No. 2 fuse from the instrument panel junction block. Measure the resistance of the fuse. Standard resistance: Below 1 ohms NG: REPLACE FUSE OK: Go to next step
2. CHECK HARNESS AND CONNECTOR (AFS ECU - BATTERY AND BODY GROUND) Disconnect the A14 ECU connector. Turn the ignition switch on. Measure the voltage and resistance of the wire harness side connector. Standard voltage TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Condition Specified Condition A14-12 (IGS) - Body ground Ignition switch ON 10 to 14 V A14-2 (IG) - Body ground Ignition switch ON 10 to 14 V Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition A14-1 (E1) - Body ground Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the P22 and T4 ECU connectors (with Driving position memory). Disconnect the P22 and G3 ECU connectors (without Driving position memory, without Tire pressure warning system). Disconnect the T23 ECU connector (with Tire pressure warning system, without Driving position memory). Measure the resistance of the wire harness side connectors. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition A14-5 (MPX1) - P22-7 (MPX1) Below 1 ohms A14-5 (MPX1) - T4-5 (MPX1) ( (1) ) Below 1 ohms A14-5 (MPX1) - G3-12 (MPD2) ( (2) ) Below 1 ohms A14-5 (MPX1) - T23-6 (MPX1) ( (3) ) Below 1 ohms (1) with Driving Position Memory (2) without Driving Position Memory, without Tire Pressure Warning System (3) with Tire Pressure Warning System, without Driving Position Memory NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE AFS ECU

HINT

When "+B or GND short malfunction of communication bus" DTCs (B1214 and B1215) are detected at the same time as "communication stop" DTC B1206, repair the "+B or GND short malfunction of communication bus" DTCs first.

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1. CHECK OPERATION Turn the ignition switch to the ON position. Check that the driver side power window can be operated using the multiplex network master switch. HINT: With this inspection, the multiplex network master switch CPU can be diagnosed if it works normally or not. OK: Power window can be operated using multiplex network master switch. OK: GO TO step 4 NG: Go to next step
2. INSPECT FUSE (ECU-B NO. 1) Remove the ECU-B No. 1 fuse from the fusible link block. Measure the resistance of the fuse. Standard resistance: Below 1 ohms NG: REPLACE FUSE OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (MULTIPLEX NETWORK MASTER SWITCH BATTERY AND BODY GROUND) Disconnect the P22 switch connector. Measure the voltage of the wire harness side connector. Standard voltage TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Connection P22-9 (CPUB) - Body ground 10 to 14 V Measure the resistance of the wire harness side connector. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Connection P22-2 (GND) - Body ground Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the G3 ECU connector (without Driving position memory, without Tire pressure warning system). Disconnect the T4 ECU connector (with Driving position memory). Disconnect the T23 ECU connector (with Tire pressure warning system, without Driving position memory). Disconnect the 1E instrument panel connector. Measure the resistance of the wire harness side connectors. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition P22-8 (MPX2) - 1E-7 (MPX1) Below 1 ohms P22-7 (MPX1) - T4-5 (MPX1) ( (1) ) Below 1 ohms P22-7 (MPX1) - G3-12 (MPD2) ( (2) ) Below 1 ohms P22-7 (MPX1) - T23-6 (MPX1) ( (3) ) Below 1 ohms (1) with Driving Position Memory (2) without Driving Position Memory, without Tire Pressure Warning System (3) with Tire Pressure Warning System, without Driving Position Memory NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE MULTIPLEX NETWORK MASTER SWITCH

HINT

When "+B or GND short malfunction of communication bus" DTCs (B1214 and B1215) are detected at the same time as "communication stop" DTC B1208, repair the "+B or GND short malfunction of communication bus" DTCs first.

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1. INSPECT FUSE (ECU-B NO. 1) Remove the ECU-B No. 1 fuse from the fusible link block. Measure the resistance of the fuse. Standard resistance: Below 1 ohms NG: REPLACE FUSE OK: Go to next step
2. CHECK HARNESS AND CONNECTOR (OUTER MIRROR CONTROL ECU - BATTERY AND BODY GROUND) Disconnect the R28 ECU connector. Measure the voltage of the wire harness side connector. Standard voltage TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Connection R28-7 (CPUB) - Body ground 10 to 14 V Measure the resistance of the wire harness side connector. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Connection R28-1 (GND) - Body ground Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the P22 and T4 ECU connectors. Measure the resistance of the wire harness side connectors. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition R28-6 (MPX1) - P22-7 (MPX1) Below 1 ohms R28-6 (MPX1) - T4-5 (MPX1) Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE OUTER MIRROR CONTROL ECU

HINT

When "+B or GND short malfunction of communication bus" DTCs (B1214 and B1215) are detected at the same time as "communication stop" DTC B1209, repair the "+B or GND short malfunction of communication bus" DTCs first.

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1. INSPECT FUSE (ECU-B NO. 1) Remove the ECU-B No. 1 fuse from the fusible link block. Measure the resistance of the fuse. Standard resistance: Below 1 ohms OK: REPLACE FUSE NG: Go to next step
2. CHECK HARNESS AND CONNECTOR (OUTER MIRROR CONTROL ECU - BATTERY AND BODY GROUND) Disconnect the R27 ECU connector. Measure the voltage of the wire harness side connector. Standard voltage TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Connection R27-7 (CPUB) - Body ground 10 to 14 V Measure the resistance of the wire harness side connector. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Connection R27-1 (GND) - Body ground Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the P22 and T4 ECU connectors. Measure the resistance of the wire harness side connectors. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition R27-6 (MPX1) - P22-7 (MPX1) Below 1 ohms R27-6 (MPX1) - T4-5 (MPX1) Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE OUTER MIRROR CONTROL ECU

HINT

When "+B or GND short malfunction of communication bus" DTCs (B1214 and B1215) are detected at the same time as "communication stop" DTC B1213, repair the "+B or GND short malfunction of communication bus" DTCs first.

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1. INSPECT FUSE (TI & TE) Remove the TI & TE fuse from the fusible link block. Measure the resistance of the fuse. Standard resistance: Below 1 ohms NG: REPLACE FUSE OK: Go to next step
2. CHECK HARNESS AND CONNECTOR (MULTIPLEX TILT AND TELESCOPIC ECU BATTERY AND BODY GROUND) Disconnect the T4 ECU connector. Measure the voltage of the wire harness side connector. Standard voltage TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition T4-2 (+B) - Body ground 10 to 14 V Measure the resistance of the wire harness side connector. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition T4-11 (GND) - Body ground Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the P22 and G3 ECU connectors (without Tire pressure warning system). Disconnect the P22 and T23 ECU connectors (with Tire pressure warning system). Measure the resistance of the wire harness side connectors. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition T4-5 (MPX1) - P22-7 (MPX1) Below 1 ohms T4-14 (MPX2) - 63-12 (MPD2) ( (1) ) Below 1 ohms T4-14 (MPX2) - T23-6 (MPX1) ( (2) ) Below 1 ohms (1) without Tire Pressure Warning System (2) with Tire Pressure Warning System

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: REPLACE MULTIPLEX TILT AND TELESCOPIC ECU

HINT

When "+B or GND short malfunction of communication bus" DTCs (B1266 and B1267) are detected at the same time as "communication stop" DTC B1245, repair the "+B or GND short malfunction of communication bus" DTCs first.

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1. CHECK OPERATION Turn the ignition switch to the ON position. Check that the auto wiper can be operated using the wiper and washer switch. HINT: With this inspection, the auto wiper ECU CPU can be diagnosed if it works normally or not. OK: Auto wiper can be operated using wiper and washer switch. NG: GO TO step 4 OK: Go to next step
2. INSPECT FUSE (FRWIP) Remove the FR WIP fuse from the instrument panel junction block. Measure the resistance of the fuse. Standard resistance: Below 1 ohms NG: REPLACE FUSE OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (AUTO WIPER ECU - BATTERY AND BODY GROUND) Disconnect the A28 and A29 ECU connectors. Turn the ignition switch to the ON position. Measure the voltage of the wire harness side connector. Standard voltage TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Connection Specified Connection A29-10 (WIG) - Body ground Ignition switch ON 10 to 14 V Measure the resistance of the wire harness side connector. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Connection A28-12 (E) - Body ground Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the A8 and A20 ECU connectors. Measure the resistance of the wire harness side connectors. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition A28-1 (MPX1) - A8-3 (MPX+) Below 1 ohms A28-1 (MPX1) - A20-22 (MPX2) Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE AUTO WIPER ECU

HINT

When "+B or GND short malfunction of communication bus" DTCs (B1214 and B1215) are detected at the same time as "communication stop" DTC B1247, repair the "+B or GND short malfunction of communication bus" DTCs first.

Scheme 67

Scheme 68

1. CHECK FUSE (ECU-IG NO. 1) Remove the ECU-IG No. 1 fuse from the fusible link block. Measure the resistance of the fuse. Standard resistance: Below 1 ohms NG: REPLACE FUSE OK: Go to next step
2. CHECK HARNESS AND CONNECTOR (TIRE PRESSURE WARNING ECU - BATTERY AND BODY GROUND) Disconnect the T23 ECU connector. Measure the voltage and resistance of the wire harness side connector. Standard voltage TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Condition Specified Condition T23-1 (IG) - Body ground Ignition switch ON 10 to 14 V Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Condition Specified Condition T23-7 (GND) - Body ground Always Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the G3 and P22 ECU connectors (without Driving position memory). Disconnect the G3 and T4 ECU connectors (with Driving position memory). Measure the resistance of the wire harness side connectors. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition T23-12 (MPX2) - 63-12 (MPD2) Below 1 ohms T23-6 (MPX1) - P22-7 (MPX1) ( (1) ) Below 1 ohms T23-6 (MPX1) - T4-14 (MPX2) ( (2) ) Below 1 ohms (1) without Driving Position Memory (2) with Driving Position Memory NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE TIRE PRESSURE WARNING ECU

HINT

When "+B or GND short malfunction of communication bus" DTCs (B1266 and B1267) are detected at the same time as "communication stop" DTC B1262, repair the "+B or GND short malfunction of communication bus" DTCs first.

Scheme 69

Scheme 70

1. CHECK FUSE (ECU-IG NO. 1) Remove the ECU-IG No. 1 fuse from the fusible link block. Measure the resistance of the fuse. Standard resistance: Below 1 ohms NG: REPLACE FUSE OK: Go to next step
2. CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER ASSEMBLY - BATTERY AND BODY GROUND) Disconnect the A8 ECU connector. Measure the voltage of the wire harness side connector. Standard voltage TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Condition Specified Condition A8-1 (IG+) - Body ground Ignition switch ON 10 to 14 V Measure the resistance of the wire harness side connector. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Condition Specified Condition A8-6 (GND) - Body ground Always Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the G3 and A20 ECU connectors. Measure the resistance of the wire harness side connectors. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition A8-4 (MPX-) - G3-4 (MPI1) Below 1 ohms A8-3 (MPX+) - A20-22 (MPX2) Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

HINT

When "+B or GND short malfunction of communication bus" DTCs (B1266 and B1267) are detected at the same time as "communication stop" DTC B1271, repair the "+B or GND short malfunction of communication bus" DTCs first.

Scheme 71

Scheme 72

1. CHECK OPERATION Check that the tachometer can operate properly while the engine is idling. HINT: With this inspection, the combination meter CPU can be diagnosed if it works normally or not. OK: Tachometer operates properly while engine is idling. OK: GO TO step 4 NG: Go to next step
2. INSPECT FUSE (ECU-B NO. 1, DOME) Remove the ECU-B No. 1 and DOME fuses from the fusible link block and instrument panel junction block. Measure the resistance of the fuses. Standard resistance: Below 1 ohms NG: REPLACE FUSE OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (COMBINATION METER - BATTERY AND BODY GROUND) Disconnect the C8 and C9 meter connectors. Measure the voltage of the wire harness side connectors. Standard voltage TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition C8-15 (B) - Body ground 10 to 14 V C8-16 (B) - Body ground 10 to 14 V Measure the resistance of the wire harness side connectors. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition C9-1 (E) - Body ground Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the A20 and G3 ECU connectors (with LEXUS navigation system). Disconnect the A20 and C4 ECU connectors (without LEXUS navigation system). Measure the resistance of the wire harness side connectors. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Condition Specified Condition C9-4 (MPX+) - A20-24 (MPX1) Below 1 ohms C8-5 (MPX-) - C4-12 (MPX-) ( (2) ) Below 1 ohms C8-5 (MPX-) - G3-13 (MPI2) ( (1) ) Below 1 ohms (1) with LEXUS Navigation System (2) without LEXUS Navigation System

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: REPLACE COMBINATION METER

HINT

When "+B or GND short malfunction of communication bus" DTCs (B1214 and B1215) are detected at the same time as "communication stop" DTC B1272, repair the "+B or GND short malfunction of communication bus" DTCs first.

Scheme 73

Scheme 74

1. CHECK OPERATION Check that the switch of the front power seat can move the driver side seat normally. HINT: With this inspection, the position control ECU & switch assembly (driver seat ECU) CPU can be diagnosed if it works normally or not. OK: Switch of the front power seat can move driver side seat normally. OK: GO TO step 4 NG: Go to next step
2. INSPECT FUSE (P/SEAT) Remove the P/SEAT fuse from the instrument panel junction block. Measure the resistance of the fuse. Standard resistance: Below 1 ohms NG: REPLACE FUSE OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (POSITION CONTROL ECU AND SWITCH BATTERY AND BODY GROUND) Disconnect the P33 ECU connector. Measure the resistance and voltage of the wire harness side connector. Standard voltage TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition P33-5 (+B) - Body ground 10 to 14 V Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition P33-1 (GND) - Body ground Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the P32, P22 and T4 ECU connectors (with Driving position memory). Disconnect the P32, P22 and G3 ECU connectors (without Driving position memory, without Tire pressure warning system). Disconnect the P32, P22 and T23 ECU connectors (with Tire pressure warning system, without Driving position memory). Measure the resistance of the wire harness side connectors. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition P32-1 (MPX1) - T4-5 (MPX1) ( (1) ) Below 1 ohms P32-1 (MPX1) - P22-7 (MPX1) Below 1 ohms P32-1 (MPX1) - G3-12 (MPD2) ( (2) ) Below 1 ohms P32-1 (MPX1) - T23-6 (MPX1) ( (3) ) Below 1 ohms (1) with Driving Position Memory (2) without Driving Position Memory, without Tire Pressure Warning System (3) with Tire Pressure Warning System, without Driving Position Memory

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: REPLACE POSITION CONTROL ECU AND SWITCH ASSEMBLY

HINT

When "+B or GND short malfunction of communication bus" DTCs (B1266 and B1267) are detected at the same time as "communication stop" DTC B1273, repair the "+B or GND short malfunction of communication bus" DTCs first.

Scheme 75

Scheme 76

1. CHECK OPERATION Check that the tilt or slide switch can operate the sliding roof normally. HINT: With this inspection, the sliding roof dive gear (sliding roof control ECU) CPU can be diagnosed if it works normally or not. OK: Tilt or slide switch can operate sliding roof normally. OK: GO TO step 4 NG: Go to next step
2. INSPECT FUSE (S/ROOF) Remove the S/ROOF fuse from the instrument panel block. Measure the resistance of the fuse. Standard resistance: Below 1 ohms NG: REPLACE FUSE OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (SLIDING ROOF CONTROL ECU - BATTERY AND BODY GROUND) Disconnect the M12 ECU connector. Measure the voltage of the wire harness side connector. Standard voltage TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition M12-1 (B) - Body ground 10 to 14 V Measure the resistance of the wire harness side connector. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition M12-7 (E) - Body ground Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the G3 and C8 ECU connectors (with LEXUS navigation system). Disconnect the C4 and C8 ECU connectors (without LEXUS navigation system). Measure the resistance of the wire harness side connectors. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition M12-10 (MPX1) - G3-13 (MPI2) ( (1) ) Below 1 ohms M12-10 (MPX1) - C4-12 (MPX-) ( (2) ) Below 1 ohms M12-10 (MPX1) - C8-5 (MPX-) Below 1 ohms (1) with LEXUS Navigation System (2) without LEXUS Navigation System NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OR OVERHEAD J/B OK: REPLACE SLIDING ROOF CONTROL ECU

HINT

When "+B or GND short malfunction of communication bus" DTCs (B1266 and B1267) are detected at the same time as "communication stop" DTC B1277, repair the "+B or GND short malfunction of communication bus" DTCs first.

Scheme 77

Scheme 78

1. INSPECT FUSE (GAUGE NO. 1) Remove the GAUGE No. 1 fuse from the instrument panel junction block. Measure the resistance of the fuse. Standard resistance: Below 1 ohms NG: REPLACE FUSE OK: Go to next step
2. CHECK HARNESS AND CONNECTOR (CENTER CLUSTER INTEGRATION PANEL BATTERY AND BODY GROUND) Disconnect the C4 panel connector. Measure the voltage of the wire harness side connector. Standard voltage TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Condition Specified Condition C4-9 (IG+) - Body ground Ignition switch ON 10 to 14 V Measure the resistance of the wire harness side connector. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition C4-7 (GND) - Body ground Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the C8 and G3 ECU connectors. Measure the resistance of the wire harness side connectors. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition C4-5 (MPX+) - G3-13 (MPI2) Below 1 ohms C4-12 (MPX-) -C8-5 (MPX-) Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE CENTER CLUSTER INTEGRATION PANEL

HINT

When "+B or GND short malfunction of communication bus" DTCs (B1266 and B1267) are detected at the same time as "communication stop" DTC B1279, repair the "+B or GND short malfunction of communication bus" DTCs first.

Scheme 79

Scheme 80

1. INSPECT FUSE (ECU-IG NO. 1) Remove the ECU-IG No. 1 fuse from the fusible link block. Measure the resistance of the fuse. Standard resistance: Below 1 ohms NG: REPLACE FUSE OK: Go to next step
2. CHECK WIRE HARNESS (RAIN SENSOR - BATTERY AND BODY GROUND) Disconnect the R7 sensor connector. Measure the voltage of the wire harness side connector. Standard voltage TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Condition Specified Condition R7-1 (SIG) - Body ground Ignition switch ON 10 to 14 V Measure the resistance of the wire harness side connector. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition R7-3 (ES) - Body ground Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the G3 and C8 ECU connectors (with LEXUS navigation system). Disconnect the C4 and C8 ECU connectors (without LEXUS navigation system). Measure the resistance of the wire harness side connectors. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition R7-2 (MPX) - G3-13 (MPI2) ( (1) ) Below 1 ohms R7-2 (MPX) - C4-12 (MPX-) ( (2) ) Below 1 ohms R7-2 (MPX) - C8-5 (MPX-) Below 1 ohms (1) with LEXUS Navigation System (2) without LEXUS Navigation System NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE RAIN SENSOR

HINT

When "+B or GND short malfunction of communication bus" DTCs (B1266 and B1267) are detected at the same time as "communication stop" DTC B1281, repair the "+B or GND short malfunction of communication bus" DTCs first.

Scheme 81

Scheme 82

1. CHECK FUSE (IGN) Remove the IGN fuse from the fusible link block. Measure the resistance of the fuse. Standard resistance: Below 1 ohms NG: REPLACE FUSE OK: Go to next step
2. CHECK HARNESS AND CONNECTOR (CENTER AIRBAG SENSOR ASSEMBLY BATTERY AND BODY GROUND) Disconnect the A20 sensor connector. Measure the voltage of the wire harness side connector. Standard voltage TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Condition Specified Condition A20-5 (IG2) - Body ground Ignition switch ON 10 to 14 V Measure the resistance of the wire harness side connector. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Condition Specified Condition A20-28 (E2) - Body ground Always Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
3. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the C9 meter connector. Disconnect the A8 amplifier connector. Measure the resistance of the wire harness side connectors. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition A20-24 (MPX1) - C9-4 (MPX+) Below 1 ohms A20-22 (MPX2) - A8-3 (MPX+) Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE CENTER AIRBAG SENSOR ASSEMBLY

When "+B or GND short malfunction of communication bus" DTCs (B1214 and B1215) are detected at the same time as "communication stop" DTC B1287, repair the "+B or GND short malfunction of communication bus" DTCs first.

Scheme 83

Scheme 84

1. CHECK OPERATION Check if the back door closer function operates normally through the power back door closer switch. HINT: With this inspection, the multiplex back door ECU CPU can be diagnosed if it works normally or not. OK: Power back door closer function operates normally. OK: GO TO step 4 NG: Go to next step
2. INSPECT FUSE (PBD) Remove the PBD fuse from the instrument panel junction block. Measure the resistance of the fuse. Standard resistance: Below 1 ohms NG: REPLACE FUSE OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (MULTIPLEX BACK DOOR ECU - BATTERY AND BODY GROUND) Disconnect the P14 ECU connector. Measure the voltage of the wire harness side connector. Standard voltage TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition P14-2 (B) - Body ground 10 to 14 V Measure the resistance of the wire harness side connector. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition P14-8 (GND) - Body ground Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the P13, P22 and T4 ECU connectors (with Driving position memory). Disconnect the P13, P22 and G3 ECU connectors (without Driving position memory, without Tire pressure warning system). Disconnect the P13, P22 and T23 ECU connectors (with Tire pressure warning system, without Driving position memory). Measure the resistance of the wire harness side connectors. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition P13-22 (MPX1) - P22-7 (MPX1) Below 1 ohms P13-22 (MPX1) - T4-5 (MPX1) ( (1) ) Below 1 ohms P13-22 (MPX1) - G3-12 (MPD2) ( (2) ) Below 1 ohms P13-22 (MPX1) - T23-6 (MPX1) ( (3) ) Below 1 ohms (1) with Driving Position Memory (2) without Driving Position Memory, without Tire Pressure Warning System (3) with Tire Pressure Warning System, without Driving Position Memory NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE MULTIPLEX BACK DOOR ECU

HINT

When "+B or GND short malfunction of communication bus" DTCs (B1214 and B1215) are detected at the same time as "communication stop" DTC B1294, repair the "+B or GND short malfunction of communication bus" DTCs first.

Scheme 85

Scheme 86

1. CHECK OPERATION Check if the engine start function operates normally through the ignition switch turned on. HINT: With this inspection, the transponder key ECU CPU can be diagnosed if it works normally or not. OK: Engine start function operates normally. OK: GO TO step 4 NG: Go to next step
2. INSPECT FUSE (MPX-B) Remove the MPX-B fuse from the instrument panel junction block. Measure the resistance of the fuse. Standard resistance: Below 1 ohms NG: REPLACE FUSE OK: Go to next step
3. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - BATTERY AND BODY GROUND) Disconnect the T9 ECU connector. Measure the voltage of the wire harness side connector. Standard voltage TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition T9-1 (CPUB) - Body ground 10 to 14 V Measure the resistance of the wire harness side connector. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition T9-14 (GND) - Body ground Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: Go to next step
4. CHECK RESISTANCE OF COMMUNICATION LINE Disconnect the B5 and G3 ECU connectors. Measure the resistance of the wire harness side connectors. Standard resistance TESTER CONNECTION SPECIFIED CONDITION CHART Tester Connection Specified Condition T9-4 (MPX1) - B5-21 (MPX2) Below 1 ohms T9-S (MPX2) -G3-3 (MPD1) Below 1 ohms NG: REPAIR OR REPLACE HARNESS OR CONNECTOR OK: REPLACE TRANSPONDER KEY ECU