Multiplex Communication: Diagnosis Lexus SC II рестайлинг

HOW TO PROCEED WITH TROUBLESHOOTING

HINT

1. Use these procedures to troubleshoot the multiplex communication system.
2. *: Use the intelligent tester.

1. VEHICLE BROUGHT TO WORKSHOP
2. INSPECT BATTERY VOLTAGE Standard voltage: 11 to 14 V If the voltage is below 11 V, recharge or replace the battery before proceeding.
3. CHECK DIAGNOSTIC TROUBLE CODE* 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.
4. OVERALL ANALYSIS AND TROUBLESHOOTING See «TERMINALS OF ECU»(ref-283178-S31853189552008041900000)
5. ADJUST, REPAIR OR REPLACE
6. CONFIRMATION TEST NEXT: END

Scheme 111

Scheme 112

Scheme 113

Scheme 114

Scheme 115

Scheme 116

Scheme 117

Scheme 118

Scheme 119

Scheme 120

Scheme 121

Scheme 122

Scheme 123

Scheme 124

Scheme 125

Scheme 126

Scheme 127

Scheme 128

Scheme 129

Scheme 130

1. CHECK NETWORK GATEWAY ECU (Scheme 111): Identifying G3 ECU Connector Terminals 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 GND (G3-24) - Body ground W-B - Body ground Ground Always Below 1 ohms BATT (G3-10) - GND (G3-22) B - W-B +B (BATT) power supply Always 10 to 14 V MPD1 (G3-3) - Body ground P-L - Body ground MPX line Always 10 kohms or higher MPD2 (G3-12) - Body ground R-L - Body ground MPX line Always 10 kohms or higher MPI1 (G3-4) - Body ground L-O - Body ground MPX line Always 10 kohms or higher MPI2 (G3-13) - Body ground Y - Body ground MPX line Always 10 kohms or higher MPL1 (G3-5) - Body ground R - Body ground MPX line Always 10 kohms or higher MPL2 (G3-14) - Body ground B-R - 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.
2. CHECK DRIVER SIDE JUNCTION BLOCK (DRIVER SIDE JUNCTION BLOCK ECU) (Scheme 112): Identifying D2 And D4 ECU Connectors Terminals Disconnect the D2 and D4 ECU connectors. Measure the voltage and resistance of the wire harness side connectors. VOLTAGE AND RESISTANCE SPECIFICATION Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition GND2 (D4-1) - Body ground W-B - Body ground Ground Always Below 1 ohms MPX-B (D4-5) - GND (2G-8) L-B - W-B +B (MPX-B) power supply Always 10 to 14 V MPX1 (D2-15) - Body ground L-Y - Body ground MPX line Always 10 kohms or higher MPX2 (D4-7) - Body ground W-L - Body ground MPX line Always 10 kohms or higher MPX3 (D4-6) - Body ground G - 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.
3. CHECK PASSENGER SIDE JUNCTION BLOCK (PASSENGER SIDE JUNCTION BLOCK ECU) (Scheme 113): Identifying 3E, 3G And 3H Junction Block And P4 And P6 ECU Connectors Terminal Disconnect the 3E, 3G and 3H junction block connectors. Disconnect the P4 and P6 ECU connectors. Measure the voltage and resistance of the wire harness side connectors. VOLTAGE AND RESISTANCE SPECIFICATION Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition GND (3G-8) - Body ground W-B - Body ground Ground Always Below 1 ohms GND1 (P4-11) - Body ground W-B - Body ground Ground Always Below 1 ohms MPX-B (3E-16) - GND (3G-8) B - W-B +B (MPX-B) power supply Always 10 to 14 V AIRBAG (3H-2) - Body ground R-L - Body ground MPX line Always 10 kohms or higher MPX- (P6-4) - Body ground Y - 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.
4. CHECK LUGGAGE ROOM JUNCTION BLOCK (LUGGAGE ROOM JUNCTION BLOCK ECU) (Scheme 114): Identifying 6F, 6J Junction Block And L24 ECU Connectors Terminal Disconnect the 6F and 6J junction block connectors. Disconnect the L24 ECU connector. Measure the voltage and resistance of the wire harness side connectors. VOLTAGE AND RESISTANCE SPECIFICATION Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition SG (L24-5) - Body ground W-B - Body ground Ground Always Below 1 ohms MPX-B (6F-12) - P-GND (6A-5) L-B - W-B +B (MPX-B) power supply Always 10 to 14 V MPX+ (L24-2) - Body ground B - Body ground MPX line Always 10 kohms or higher MPX- (L24-13) - Body ground R - 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.
5. CHECK MULTIPLEX NETWORK FRONT DOOR ECU LH (Scheme 115): Identifying D17 And D19 ECU Connectors Disconnect the D17 and D19 ECU connectors. Measure the voltage and resistance of the wire harness side connectors. VOLTAGE AND RESISTANCE SPECIFICATION Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition GND (D19-1) - Body ground W-B - Body ground Ground Always Below 1 ohms CPUB (D19-4) - GND (C1) L-O - W-B +B (CPUB) power supply Always 10 to 14 V BDR (D19-6) - GND (D19-1) B-R - W-B +B (BDR) power supply Always 10 to 14 V MPX1 (D17-22) - Body ground R-L - Body ground MPX line Always 10 kohms or higher MPX2 (D17-30) - Body ground O - 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.
6. CHECK MULTIPLEX NETWORK FRONT DOOR ECU RH (Scheme 116): Identifying P9 And P11 ECU Connectors Disconnect the P9 and P11 ECU connectors. Measure the voltage and resistance of the wire harness side connectors. VOLTAGE AND RESISTANCE SPECIFICATION Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition GND (P11-1) - Body ground W-B - Body ground Ground Always Below 1 ohms CPUB (P11-4) - GND (P11-1) L-O - W-B +B (CPUB) power supply Always 10 to 14 V BDR (P11-6) - GND (P11-1) G-Y - W-B +B (BDR) power supply Always 10 to 14 V MPX1 (P9-22) - Body ground R-L - Body ground MPX line Always 10 kohms or higher MPX2 (P9-30) - Body ground B-Y - 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.
7. CHECK TIRE PRESSURE MONITOR RECEIVER ASSEMBLY (Scheme 117): Identifying T9 ECU Connector Disconnect the T9 ECU connector. Measure the voltage and resistance of the wire harness side connector. VOLTAGE AND RESISTANCE SPECIFICATION Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition GND (T9-6) - Body ground W-B - Body ground Ground Always Below 1 ohms +B (T9-1) - GND (T9-6) B - W-B +B power supply Always 10 to 14 V MPX1 (T9-2) - Body ground L-O - Body ground MPX line Always 10 kohms or higher MPX2 (T9-3) - Body ground R-L - 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.
8. CHECK THEFT WARNING ECU (Scheme 118): Identifying T7 ECU Connector Disconnect the T7 ECU connector. Measure the voltage and resistance of the wire harness side connector. VOLTAGE AND RESISTANCE SPECIFICATION Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition GND (T7-20) - Body ground W-B - Body ground Ground Always Below 1 ohms +B2 (T7-21) - GND (T7-20) B-O - W-B +B (+B2) power supply Always 10 to 14 V MPX (T7-13) - Body ground V - Body ground MPX line Always 10 kohms or higher MPX2 (T7-33) - Body ground BR - 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.
9. CHECK TRANSPONDER KEY ECU (Scheme 119): Identifying T13 ECU Connector Disconnect the T13 ECU connector. Measure the voltage and resistance of the wire harness side connector. VOLTAGE AND RESISTANCE SPECIFICATION Symbols (Terminal No.) Wiring Color Terminal inscription Condition Specified Condition GND (T13-14) - Body ground W-B - Body ground Ground Always Below 1 ohms CPUB (T13-1) - GND (T13-14) L-O - W-B +B (CPUB) power supply Always 10 to 14 V MPX1 (T13-4) - Body ground BR - Body ground MPX line Always 10 kohms or higher MPX2 (T13-5) - Body ground P-L - 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.
10. CHECK TURN SIGNAL SWITCH ASSEMBLY (Scheme 120): Identifying C11 Switch Connector Disconnect the C11 switch connector. Measure the voltage and resistance of the wire harness side connector. VOLTAGE AND RESISTANCE SPECIFICATION Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition E (C11-8) - Body ground W-B - Body ground Ground Always Below 1 ohms B (C11-1) - E (C11-8) L-B - W-B +B (B) power supply Always 10 to 14 V MPX1 (C11-9) - Body ground V - Body ground MPX line Always 10 kohms or higher MPX2 (C11-10) - Body ground B - 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.
11. CHECK MULTIPLEX NETWORK FRONT LIGHT ECU (Scheme 121): Identifying Multiplex Network Front Light ECU Relay Measure the voltage and resistance of the connectors. NOTE: The inspection should be performed from the backside of the relay block with the multiplex network front light ECU connector connected. VOLTAGE AND RESISTANCE SPECIFICATION Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition GND (12) - Body ground W-B - Body ground Ground Always Below 1 ohms FMB3 (8) - GND (12) L-B - W-B +B (FMB3) power supply Always 10 to 14 V MPX1 (5) - Body ground B-R - Body ground MPX line Always 10 kohms or higher MPX2 (6) - Body ground W-L - 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.
12. CHECK STEERING PAD SWITCH MODULATOR (Scheme 122): Identifying C10 Modulator Connector Disconnect the C10 modulator connector. Measure the voltage and resistance of the wire harness side connector. VOLTAGE AND RESISTANCE SPECIFICATION Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition ECC (C10-4) - Body ground BR - Body ground Ground Always Below 1 ohms +B (C10-2) - ECC (C10-4) B-O - BR +B power supply Ground Always 10 to 14 V MPX (C10-3) - Body ground G - 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.
13. CHECK MULTIPLEX TILT AND TELESCOPIC ECU (Scheme 123): Identifying T8 ECU Connector Disconnect the T8 ECU connector. Measure the voltage and resistance of the wire harness side connector. VOLTAGE AND RESISTANCE SPECIFICATION Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition GND (T8-4) - Body ground W-B - Body ground Ground Always Below 1 ohms ECUB (T8-5) - GND (T8-4) L-B - W-B +B (ECU) power supply Always 10 to 14 V +B (T8-10) - GND (T8-4) L-W - W-B +B power supply Always 10 to 14 V MPX1 (T8-7) - Body ground W-L - Body ground MPX line Always 10 kohms or higher MPX2 (T8-6) - Body ground V - 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 COMBINATION METER ASSEMBLY (Scheme 124): Identifying C8 Meter Connector Disconnect the C8 meter connector. Measure the voltage and resistance of the wire harness side connectors. VOLTAGE AND RESISTANCE SPECIFICATION Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition ES (C8-12) - Body ground BR - Body ground Ground Always Below 1 ohms +B (C8-13) - ES (C8-12) B - BR +B power supply Always 10 to 14 V MPX+ (C8-3) - Body ground Y - Body ground MPX line Always 10 kohms or higher MPX- (C8-4) - Body ground L-O - 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.
15. CHECK SKID CONTROL ECU (Scheme 125): Identifying S5, S6, S7 And S8 ECU Connectors Disconnect the S5, S6, S7 and S8 ECU connectors. Measure the voltage and resistance of the wire harness side connectors. VOLTAGE AND RESISTANCE SPECIFICATION Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition GND1 (S8-31) - Body ground W-B - Body ground Ground Always Below 1 ohms GND2 (S8-6) - Body ground W-B - Body ground Ground Always Below 1 ohms GND3 (S5-22) - Body ground W-B - Body ground Ground Always Below 1 ohms GND4 (S5-16) - Body ground W-B - Body ground Ground Always Below 1 ohms IG1 (S7-6) - GND1 (S8-31) R - W-B Ignition (IG1) power supply Ignition switch ON 10 to 14 V IG2 (S6-6) - GND1 (S8-31) G-B - W-B Ignition (IG2) power supply Ignition switch ON 10 to 14 V MPX1 (S6-17) - Body ground L-O - Body ground MPX line Always 10 kohms or higher MPX2 (S7-3) - Body ground R-L - 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.
16. CHECK A/C AMPLIFIER ASSEMBLY (Scheme 126): Identifying A9 And A10 ECU Connectors Disconnect the A9 and A10 ECU connectors. Measure the voltage and resistance of the wire harness side connectors. VOLTAGE AND RESISTANCE SPECIFICATION Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition GND (A10-14) - Body ground W-B - Body ground Ground Always Below 1 ohms +B (A10-8) - GND (A10-14) W-R - W-B +B power supply Always 10 to 14 V IG (A10-1) - GND (A10-14) V-W - W-B Ignition (IG+) power supply Ignition switch ON 10 to 14 V MPX+ (A10-13) - Body ground L-O - Body ground MPX line Always 10 kohms or higher MPX- (A9-10) - Body ground R-L - 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.
17. CHECK SLIDING ROOF CONTROL ECU (Scheme 127): Identifying S18 And S19 ECU Connectors Disconnect the S18 and S19 ECU connectors. Measure the voltage and resistance of the wire harness side connectors. VOLTAGE AND RESISTANCE SPECIFICATION Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition E1 (S18-6) - Body ground W-B - Body ground Ground Always Below 1 ohms E2 (S19-9) - Body ground W-B - Body ground Ground Always Below 1 ohms E3 (S19-10) - Body ground W-B - Body ground Ground Always Below 1 ohms E4 (S19-11) - Body ground W-B - Body ground Ground Always Below 1 ohms E5 (S18-5) - Body ground W-B - Body ground Ground Always Below 1 ohms SGND (S18-19) - Body ground BR - Body ground Ground Always Below 1 ohms CPUB (S19-8) - E1 (S18-6) L-O - W-B +B (CPUB) power supply GND Always 10 to 14 V MPX1 (S18-7) - Body ground B-Y - Body ground MPX line Always 10 kohms or higher MPX2 (S18-1) - Body ground G - 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.
18. CHECK POSITION CONTROL ECU (DRIVER SEAT ECU) (Scheme 128): Identifying P21 And P22 ECU Connectors Disconnect the P21 and P22 ECU connectors. Measure the voltage and resistance of the wire harness side connectors. VOLTAGE AND RESISTANCE SPECIFICATION Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition GND1 (P22-7) - Body ground W-B - Body ground Ground Always Below 1 ohms +B (P22-8) - GND (P22-7) L-W - W-B +B power supply Always 10 to 14 V SYSB (P21-9) - GND (P22-7) L-O - W-B +B (SYSB) power supply Always 10 to 14 V MPX1 (P21-10) - Body ground P-L - Body ground MPX line Always 10 kohms or higher MPX2 (P21-11) - Body ground R-L - 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.
19. CHECK POSITION CONTROL ECU (PASSENGER SEAT ECU) (Scheme 129): Identifying P23 And P24 ECU Connectors Disconnect the P23 and P24 ECU connectors. Measure the voltage and resistance of the wire harness side connectors. VOLTAGE AND RESISTANCE SPECIFICATION Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition GND (P24-7) - Body ground W-B - Body ground Ground Always Below 1 ohms +B (P24-8) - GND (P22-7) L-W - W-B +B power supply Always 10 to 14 V SYSB (P23-9) - GND (P24-7) L-O - W-B +B (SYSB) power supply Always 10 to 14 V MPX1 (P23-10) - Body ground G - Body ground MPX line Always 10 kohms or higher MPX2 (P23-11) - Body ground P-L - 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.
20. CHECK AFS ECU (Scheme 130): Identifying A31 ECU Connector Disconnect the A31 ECU connector. Measure the voltage and resistance of the wire harness side connector. VOLTAGE AND RESISTANCE SPECIFICATION Symbols (Terminal No.) Wiring Color Terminal Description Condition Specified Condition IG (A31-2) - Body ground R-L - Body ground +B (+B) power supply Ignition switch ON 10 to 14 V MPX1 (A31-5) - Body ground W-L - Body ground MPX line Always 10 kohms or higher MPX2 (A31-6) - Body ground L-Y - Body ground MPX line Always 10 kohms or higher E1 (A31-1) - 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.
21. CHECK AIRBAG ECU Refer to the airbag system (see «TERMINALS OF ECU»(ref-283183-S30862545642008041900000) ).
22. CHECK RADIO RECEIVER ASSEMBLY Refer to the audio system (see «TERMINALS OF ECU»(ref-283181-S19045608592008041900000) ).

Scheme 131

Scheme 132

1. DESCRIPTION The network gateway ECU controls the functions of the Multiplex Communication System (MPX) of the vehicle. Data of the MPX and the Diagnostic Trouble Codes (DTCs) can be read in the Data Link Connector 3 (DLC3) of the vehicle.
2. CHECK DLC3 The vehicle uses ISO 9141-2 communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 9141-2 format. (Scheme 131): Identifying DLC3 Connectors Terminal VOLTAGE AND RESISTANCE SPECIFICATION Symbols (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 11 to 14 V HINT: Connect the cable of the intelligent tester to the DLC3, turn the ignition switch ON and attempt to use the tester. If the screen displays the message UNABLE TO CONNECT TO VEHICLE, there is a problem either with the vehicle or the tester. If communication is normal when the tester (with CAN VIM) is connected to another vehicle, inspect the DLC3 on the original vehicle. If communication is still impossible when the tester is connected to another vehicle, the problem is probably in the tester itself. (Scheme 132): Connecting Intelligent Tester To DLC3

Scheme 133

1. CHECK DTC Connect the intelligent tester (with CAN VIM) to the DLC3. Turn the ignition switch ON. Read 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 ON. Erase the DTCs following the prompts on the tester screen. HINT: Refer to the intelligent tester operator's manual for further details. (Scheme 133): Connecting Intelligent Tester To DLC3

DIAGNOSTIC TROUBLE CODE CHART

DIAGNOSTIC TROUBLE CODE CHART