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Multiplex Control System: Diagnosis Lexus GS II

Communication Devices 13 illustrations ~4156 words

SELF-DIAGNOSTICS

WARNINGDeactivate air bag system before performing any service operation. See AIR BAG RESTRAINT SYSTEMS article. DO NOT apply electrical power to any component on steering column without first deactivating air bag system. Air bag may deploy.

Body No. 1 ECU Inspection

  1. Check trunk release operation. If operation is okay, go to next step. If operation is faulty, diagnose and repair trunk release. See POWER DOOR LOCKS, TRUNK LID & FUEL DOOR article. Repair as necessary. If operation is okay, replace body No. 1 ECU.
  2. Open any door. Open door indicator light should glow. If open door indicator light glows, see RETRIEVING TROUBLE CODES. If open door indicator light does not glow, repair or replace open door indicator light as necessary.

Testing

  1. Verify driver's door power window operates properly in auto up mode. If operation is okay, go to next step. If operation is not as specified, check the driver's door ECU. See POWER DOOR LOCKS, TRUNK LID & FUEL DOOR article. Replace if necessary.
  2. Disconnect 25-pin connector B6 from body No. 2 ECU. Disconnect Gray 18-pin connector D24 from driver's door ECU. Disconnect 25-pin connector R12 from left rear door ECU. Check continuity of Blue/Orange wire between body No. 2 ECU connector B6 terminal No. 9 and driver's door ECU connector D24 terminal No. 9. (Scheme 2)and (Scheme 3). Check continuity of Orange wire between driver's door ECU connector D24 terminal No. 18 and left rear door ECU connector R13 terminal No. 4. (Scheme 3)and (Scheme 4). If continuity does not exist, repair or replace wiring harness or connectors between body ECU and driver's door ECU and/or driver's door ECU and left rear door ECU. If continuity exists, replace driver's door ECU.

Scheme 2

Scheme 2
Scheme 2

Scheme 3

Scheme 3
Scheme 3

Scheme 4

Scheme 4
Scheme 4
  1. Verify passenger door power window operates properly in auto up mode. If operation is okay, go to next step. If operation is not as specified, replace passenger door ECU.
  2. Disconnect 25-pin connector B5 from body No. 1 ECU. Disconnect Gray 18-pin connector F18 from passenger door ECU. Disconnect 25-pin connector R13 from right rear door ECU. Check continuity of Blue/Orange wire between body No. 1 ECU connector B5 terminal No. 9 and passenger door ECU connector F11 terminal No. 18. (Scheme 2)and (Scheme 3). Check continuity of Orange wire between passenger door ECU connector F11 terminal No. 9 and right rear door ECU connector R13 terminal No. 4. (Scheme 3)and (Scheme 4). If continuity does not exist, repair or replace wiring harness or connectors between body ECU and passenger door ECU and/or passenger door ECU and right rear ECU. If continuity exists, replace passenger door ECU.
  1. Verify manual tilt and telescopic operation. If operation is okay, go to next step (with navigation system) or step 3) (without navigation system). If operation is not as specified, replace tilt and telescopic ECU.
  2. Disconnect 18-pin connector C13 from instrument panel. Disconnect Gray 10-pin connector T5 from tilt and telescopic ECU. Disconnect 16-pin connector M3 from multi-display ECU. Check continuity of White wire, through connector and Blue wire between instrument panel connector C13 terminal No. 2 and tilt and telescopic ECU connector T5 terminal No. 6. (Scheme 5)and (Scheme 6). Check continuity of White wire between tilt and telescopic ECU connector T5 terminal No. 7 and multi-display ECU connector M3 terminal No. 8. (Scheme 6)and (Scheme 7). If continuity does not exist, repair or replace wiring harness or connectors between instrument panel and tilt and telescopic ECU and/or tilt and telescopic ECU and multi-display ECU. If continuity exists, replace tilt and telescopic ECU.
  3. Disconnect 18-pin connector C13 from instrument panel. Disconnect Gray 10-pin connector T5 from tilt and telescopic ECU. Disconnect 22-pin connector A13 from A/C control assembly. Check continuity of White wire, through connector and Blue wire between instrument panel connector C13 terminal No. 2 and tilt and telescopic ECU connector T5 terminal No. 6. Check continuity of White wire between tilt and telescopic ECU connector T5 terminal No. 7 and A/C control assembly connector A13 terminal No. 16. If continuity does not exist, repair or replace wiring harness or connectors between instrument panel and tilt and telescopic ECU and/or tilt and telescopic ECU and A/C control assembly. If continuity exists, replace tilt and telescopic ECU.

Scheme 5

Scheme 5
Scheme 5

Scheme 6

Scheme 6
Scheme 6

Scheme 7

Scheme 7
Scheme 7
  1. Disconnect Gray 18-pin connector D24 from driver's door ECU. Recheck for DTCs. If B1214 ( 14 ) or B1215 ( 15 ) exists, go to next step. If B1214 ( 14 ) and B1215 ( 15 ) does not exist, replace driver's door ECU.
  2. Reconnect Gray 18-pin connector D24 to driver's door ECU. Disconnect 25-pin connector R12 from left rear door ECU. Recheck for DTCs. If B1214 ( 14 ) or B1215 ( 15 ) exists, go to next step (with driver position memory) or step 4) (without driver position memory). If B1214 ( 14 ) and B1215 ( 15 ) does not exist, replace left rear door ECU.
  3. Reconnect 25-pin connector R12 to left rear door ECU. Disconnect 22-pin connector P19 from power seat ECU. Recheck for DTCs. If B1214 ( 14 ) or B1215 ( 15 ) exists, go to next step. If B1214 ( 14 ) and B1215 ( 15 ) does not exist, replace power seat ECU.
  4. Reconnect 25-pin connector R12 to left rear door ECU (without driver position memory). Reconnect 22-pin connector P19 to power seat ECU (with driver position memory). Disconnect 25-pin connector R13 from right rear door ECU. Recheck for DTCs. If B1214 ( 14 ) or B1215 ( 15 ) exists, go to next step. If B1214 ( 14 ) and B1215 ( 15 ) does not exist, replace right rear door ECU.
  5. Reconnect 25-pin connector R13 to right rear door ECU. Disconnect Gray 18-pin connector F11 from passenger door ECU. Recheck for DTCs. If B1214 ( 14 ) or B1215 ( 15 ) exists, go to next step. If B1214 ( 14 ) and B1215 ( 15 ) does not exist, replace passenger door ECU.
  6. Disconnect 25-pin connector R13 from right rear door ECU (passenger and right rear door ECUs are disconnected). Recheck for DTCs. If B1214 ( 14 ) or B1215 ( 15 ) exists, go to next step (with driver position memory) or step 9) (without driver position memory). If B1214 ( 14 ) and B1215 ( 15 ) do not exist, repair wiring harness between passenger door ECU and right rear door ECU.
  7. Reconnect Gray 18-pin connector F11 to passenger door ECU. Disconnect 22-pin connector P19 from power seat ECU (right rear door and power seat ECUs are disconnected). Recheck for DTCs. If B1214 ( 14 ) or B1215 ( 15 ) exists, go to next step. If B1214 ( 14 ) and B1215 ( 15 ) do not exist, repair wiring harness between right rear door ECU and power seat ECU.
  8. Reconnect 25-pin connector R13 to right rear door ECU. Disconnect 25-pin connector R12 from left rear door ECU (left rear door and power seat ECUs are disconnected). Recheck for DTCs. If B1214 ( 14 ) or B1215 ( 15 ) exists, go to next step. If B1214 ( 14 ) and B1215 ( 15 ) do not exist, repair wiring harness between left rear door ECU and power seat ECU.
  9. Reconnect 22-pin connector P19 to power seat ECU (with driver position memory). Reconnect 25-pin connector R13 to right rear door ECU (without driver position memory). Disconnect 18-pin connector D24 from driver's door ECU (left rear door and driver's door ECUs are disconnected). Recheck for DTCs. If B1214 ( 14 ) or B1215 ( 15 ) exists, go to next step. If B1214 ( 14 ) and B1215 ( 15 ) do not exist, repair wiring harness between left rear door ECU and driver's door ECU.
  10. Reconnect 25-pin connector R12 to left rear door ECU. Disconnect 25-pin connector B6 from body No. 2 ECU and remove ECU from driver's side junction block (driver's door and body No. 2 ECUs are disconnected). Recheck for DTCs. If B1214 ( 14 ) or B1215 ( 15 ) exists, go to next step. If B1214 ( 14 ) and B1215 ( 15 ) do not exist, repair wiring harness between driver's door ECU and body No. 2 ECU.
  11. Reconnect 18-pin connector D24 to driver's door ECU. Reinstall body No. 2 ECU. Disconnect 10-pin connector M5 from sun roof ECU. Disconnect Gray 18-pin connector F11 from passenger door ECU. Disconnect 25-pin B5 connector from body No. 1 ECU and remove ECU from passenger side junction block. Check continuity of Blue/Orange wire between passenger door ECU 18-pin connector F11 terminal No. 18 and body No. 1 ECU 25-pin B5 connector terminal No. 9. Check continuity of Orange wire between sun roof ECU 10-pin connector M5 terminal No. 2 and body No. 1 ECU 25-pin B5 connector terminal No. 9. If continuity does not exist, repair wiring as necessary. If continuity exists, replace body No. 1 ECU.
  1. Verify manual right rear window auto up operation. If operation is okay, go to next step. If auto up operation is not normal, replace right rear door ECU.
  2. Disconnect Gray 18-pin connector F11 from passenger door ECU. Disconnect 25-pin connector R13 from right rear door ECU. Check continuity of Orange wire between passenger door ECU connector F11 terminal No. 9 and right rear door ECU connector R13 terminal No. 4. (Scheme 3)and (Scheme 4). If continuity exists, go to next step. If continuity does not exist, repair wiring as necessary.
  3. On models with driver position memory, disconnect 22-pin connector P19 from power seat ECU and go to next step. On models without driver position memory, disconnect 25-pin connector R12 from left rear door ECU and go to step 5).
  4. Check continuity of Blue/Orange wire, through connector, Blue/Yellow wire, through connector and Orange wire between right rear door ECU connector R13 terminal No. 5 and power seat ECU connector P19 terminal No. 11. (Scheme 4)and (Scheme 8). See WIRING DIAGRAMS. Disconnect left rear door ECU 25-pin connector R12. Check continuity of Blue/Orange wire between power seat ECU connector P19 terminal No. 10 and left rear door ECU connector R12 terminal No. 4. If continuity does not exist, repair wiring as necessary. If continuity exists, replace right rear door ECU.
  5. Check continuity of Blue/Orange wire, through connectors, between right rear door ECU connector R13 terminal No. 5 and left rear door ECU connector R12 terminal No. 4. (Scheme 4) If continuity does not exist, repair wiring as necessary. If continuity exists, replace right rear door ECU.

Scheme 8

Scheme 8
Scheme 8
  1. Verify manual left rear window auto up operation. If operation is okay, go to next step. If auto up operation is not normal, replace left rear door ECU.
  2. Disconnect Gray 18-pin connector D24 from driver's door ECU. Disconnect 25-pin connector R12 from left rear door ECU. Check continuity of Orange wire between driver's door ECU connector D24 terminal No. 18 and left rear door ECU connector R12 terminal No. 5. (Scheme 3)and (Scheme 4). If continuity exists, go to next step. If continuity does not exist, repair wiring as necessary.
  3. On models with driver position memory, disconnect 22-pin connector P19 from power seat ECU and go to next step. On models without driver position memory, disconnect 25-pin connector R13 from right rear door ECU and go to step 5).
  4. Check continuity of Blue/Orange wire between power seat ECU connector P19 terminal No. 10 and left rear door ECU connector R12 terminal No. 4. (Scheme 4)and (Scheme 8). Disconnect 25-pin connector R13 from right rear door ECU. Check continuity of Blue/Orange wire, through connector, Blue/Yellow wire, through connector and Orange wire between right rear door ECU connector R13 terminal No. 5 and power seat ECU connector P19 terminal No. 11. See WIRING DIAGRAMS. If continuity does not exist, repair wiring as necessary. If continuity exists, replace left rear door ECU.
  5. Check continuity of Blue/Orange wire, through connectors, between right rear door ECU connector R13 terminal No. 5 and left rear door ECU connector R12 terminal No. 4. (Scheme 4) If continuity does not exist, repair wiring as necessary. If continuity exists, replace left rear door ECU.
  1. Verify headlights turn on using light switch with ignition off. If operation is okay, go to next step. If operation is not as specified, replace body No. 2 ECU.
  2. Disconnect 25-pin connector B6 from body No. 2 ECU. Disconnect Gray 18-pin connector D24 from driver's door ECU. Disconnect 18-pin connector C13 from instrument panel ECU. Check continuity of Blue/Orange wire between body No. 2 ECU connector B6 terminal No. 9 and driver's door ECU connector D24 terminal No. 9. (Scheme 2)and (Scheme 3). Check continuity of White wire between body No. 2 ECU connector B6 terminal No. 19 and instrument panel ECU connector C13 terminal No. 11. (Scheme 2)and (Scheme 5).
  3. If continuity does not exist, repair or replace wiring harness or connectors between body No. 2 ECU and driver's door ECU and/or instrument panel ECU. If continuity exists, replace body No. 2 ECU.

TEST NO. 9 - LIMIT SWITCH CIRCUIT COMMUNICATION PROBLEM

Code is set when problem is detected in limit switch in power window motor. Check applicable switch. See POWER WINDOWS article. Check wiring harness. See WIRING DIAGRAMS. Repair as necessary. Applicable codes are

  1. B1231/31 DRIVER'S DOOR LIMIT SWITCH CIRCUIT
  2. B1233/33 PASSENGER'S DOOR LIMIT SWITCH CIRCUIT
  3. B1235/35 RIGHT REAR DOOR LIMIT SWITCH CIRCUIT
  4. B1237/37 LEFT REAR DOOR LIMIT SWITCH CIRCUIT

TEST NO. 10 - PULSE SWITCH CIRCUIT COMMUNICATION PROBLEM

Code is set when problem is detected in pulse switch in power window motor. Check applicable switch. See POWER WINDOWS article. Check wiring harness. See WIRING DIAGRAMS. Repair as necessary. Applicable codes are

  1. B1232/32 DRIVER'S DOOR PULSE SWITCH CIRCUIT
  2. B1234/34 PASSENGER'S DOOR PULSE SWITCH CIRCUIT
  3. B1236/36 RIGHT REAR DOOR PULSE SWITCH CIRCUIT
  4. B1238/38 LEFT REAR DOOR PULSE SWITCH CIRCUIT
  1. Disconnect 7-pin W5 connector from remote keyless entry ECU. Disconnect 25-pin B5 connector from body No. 1 ECU. Check continuity between body No. 1 ECU B5 connector terminal No. 4 (Pink wire) and ground. If continuity does not exist, go to next step. If continuity exists, repair short to ground on Pink wire.
  2. Reconnect 25-pin B5 connector to body No. 1 ECU. Recheck DTCs. If B1242 ( 42 ) exists, replace body No. 1 ECU. If B1242 ( 42 ) does not exist, replace remote keyless entry ECU.

TEST NO. 12 - GSW TERMINAL CIRCUIT PROBLEM

These codes set when body No. 1 ECU detects a problem in wiring between air bag sensor assembly and body No. 2 ECU ( 53 ) or wiring between body No. 2 ECU and body No. 1 ECU ( 54 ). Applicable codes are

  1. B1243/43 GSW TERMINAL CIRCUIT
  2. B1253/53 GSW TERMINAL CIRCUIT (LOW)
  3. B1254/54 GSW TERMINAL CIRCUIT (HIGH)
  1. Disconnect 25-pin B5 connector from body No. 1 ECU. Disconnect 25-pin B6 connector from body No. 2 ECU. Disconnect Yellow C8 connector from air bag sensor assembly. Check continuity of Blue wire between air bag sensor assembly C8 connector terminal No. 4 and body No. 2 ECU B6 connector terminal No. 18. (Scheme 2)and (Scheme 9). Check continuity of Orange wire between body No. 2 ECU B6 connector terminal No. 1 and body No. 1 ECU B5 connector terminal No. 3. (Scheme 2) If continuity exists, go to next step. If continuity does not exist, repair open circuit in wiring harness.
  2. Check continuity between body No. 2 ECU B6 connector terminal No. 18 (Blue wire) and ground. Check continuity between body No. 2 ECU B6 connector terminal No. 1 (Orange wire) and ground. If continuity does not exist, go to next step. If continuity exists, repair short to ground on wiring harness.
  3. Replace air bag sensor assembly with known good unit. If no DTC exists, original air bag sensor assembly was cause. If DTC still exists, replace body No. 1 ECU.

Scheme 9

Scheme 9
Scheme 9
  1. Connect tester to DLC3, located under left side of instrument panel. Turn ignition and tester on. Check output frequency of light sensor. If frequency is 400-1200 Hz, go to next step. If frequency is not 400-1200 Hz, replace light sensor.
  2. Check wiring harness and connectors between Black 4-pin light sensor connector A30 and body No. 2 ECU. See WIRING DIAGRAMS. Repair if necessary. If no problem is found, replace body No. 2 ECU.
  1. Check P1 switch voltage by backprobing 10-pin shift lock control ECU connector S4, located to right of shifter. See SHIFT LOCK CONTROL ECU VOLTAGE TEST table. (Scheme 10) P1 switch output is located on terminal No. 7. If voltage is as specified, go to next step. If voltage is not as specified, replace shift lock control ECU.
  2. Check wiring harness and connectors. See WIRING DIAGRAMS. Repair or replace if necessary. If no problem is found, replace body No. 2 ECU.
Terminal No. (Wire Color) (1) and (8)Shifter Position(2) Voltage
1 (Blue/Red)PARK (2)0
1 (Blue/Red)Any Except PARK (2)(3)
4 (Gray)(4)10-14
4 (Gray)(2)10-14
7 (Green/Orange)PARK (2)0
7 (Green/Orange)Any Except PARK (2)10-14
8 (Green/Yellow)PARK (4)10-14
8 (Green/Yellow)(4) , (5)3-6
8 (Green/Yellow)Any Except PARK (4) , (6)0
8 (Green/Yellow)Any Except PARK (2)3-6
10 (Black/White) (7)Always0
(1) (Scheme 10) (2) Connect negative lead to terminal No. 10 (White/Black wire). (3) Ignition switch in ACC position. (4) 7.5-11 volts for about one second, 6-9 volts after one second. (5) Ignition switch in ON position. (6) Neutral or brake pedal depressed. (7) Brake pedal released. (8) Connect negative lead to ground.
(2)Connect negative lead to terminal No. 10 (White/Black wire).
(3)Ignition switch in ACC position.
(4)7.5-11 volts for about one second, 6-9 volts after one second.
(5)Ignition switch in ON position.
(6)Neutral or brake pedal depressed.
(7)Brake pedal released.
(8)Connect negative lead to ground.

SHIFT LOCK CONTROL ECU VOLTAGE TEST

Scheme 10

Scheme 10
Scheme 10
  1. Check ECM by starting engine. If engine starts and runs, go to next step. If engine does not start, replace ECM.
  2. Disconnect 25-pin B5 connector from body No. 1 ECU. Disconnect 22-pin A13 connector from A/C control assembly. Disconnect 28-pin E5 connector from ECM (GS300) or 26-pin E7 connector from ECM (GS400).
  3. Check continuity of White wire between body No. 1 ECU connector B5 terminal No. 19 and ECM connector E5 terminal No. 28 (GS300) or ECM connector E7 terminal No. 11 (GS400). Check continuity of Blue wire between A/C control assembly connector A13 terminal No. 5 and ECM connector E5 terminal No. 27 (GS300) or ECM connector E7 terminal No. 24 (GS400).
  4. If continuity exists on both wires, replace ECM. If continuity does not exist or one or both wires, repair wiring as necessary.

Scheme 11

Scheme 11
Scheme 11

Scheme 12

Scheme 12
Scheme 12

Scheme 13

Scheme 13
Scheme 13
  1. Disconnect 16-pin M3 connector from multi-display ECU (with navigation system) or 10-pin T5 connector from tilt/telescopic ECU (without navigation system). Disconnect 22-pin A13 connector from A/C control assembly. Disconnect 28-pin E5 connector from ECM (GS300) or 26-pin E7 connector from ECM (GS400).
  2. Check continuity of Blue wire between A/C control assembly connector A13 terminal No. 5 and ECM connector E5 terminal No. 27 (GS300) or ECM connector E7 terminal No. 24 (GS400).
  3. On models without navigation system, check continuity of White wire between A/C control assembly connector A13 terminal No. 16 and tilt/telescopic ECU connector T5 terminal No. 7. (Scheme 6)and (Scheme 13). On models with navigation system, check continuity of Blue/Red wire between A/C control assembly connector A13 terminal No. 16 and multi-display ECU connector M3 terminal No. 2. (Scheme 7)and (Scheme 13).
  4. If continuity exists on both wires, replace A/C control assembly. If continuity does not exist or one or both wires, repair wiring as necessary.

TEST NO. 17 - INSTRUMENT PANEL COMMUNICATION BUS SHORTED PROBLEM

Note. This DTC cannot be displayed using instrument panel light. Code can only be read using LEXUS hand-held tester.

  1. Disconnect 28-pin E5 connector (GS300) or 26-pin E7 connector (GS400) from ECM. Recheck for DTCs. If B1266 or B1267 exists, go to next step. If B1266 and B1267 do not exist, replace ECM.
  2. Reconnect ECM connector. Disconnect 22-pin connector A13 from left A/C control assembly. Recheck for DTCs. On models with navigation system, if B1266 or B1267 exists, go to next step. On models without navigation system, if B1266 or B1267 exists, go to step 4). On all models, if B1266 and B1267 do not exist, replace A/C control assembly.
  3. Reconnect 22-pin connector A13 to A/C control assembly. Disconnect 16-pin connector M3 from multi-display ECU. Recheck for DTCs. If B1266 or B1267 exists, go to next step. If B1266 and B1267 do not exist, replace multi-display ECU.
  4. On models without navigation system, reconnect 22-pin connector A13 to A/C control assembly. On models with navigation system, 16-pin connector M3 from multi-display ECU. On all models, disconnect 10-pin connector T5 from tilt/telescopic ECU. Recheck for DTCs. If B1266 or B1267 exists, go to next step. If B1266 and B1267 do not exist, replace tilt/telescopic ECU.
  5. Reconnect 10-pin connector T5 to tilt/telescopic ECU. Disconnect 18-pin connector C13 from instrument panel ECU. Recheck for DTCs. If B1266 or B1267 exists, go to next step. If B1266 and B1267 do not exist, replace instrument panel ECU.
  6. Reconnect 18-pin connector C13 to instrument panel ECU. Disconnect 25-pin connector B6 from body No. 2 ECU. Disconnect body No. 2 ECU from driver's side junction block. Recheck for DTCs. If B1266 or B1267 exists, go to next step. If B1266 and B1267 do not exist, replace body No. 2 ECU.
  7. Disconnect 18-pin connector C13 from instrument panel ECU (instrument panel and body No. 2 ECUs are disconnected). Recheck for DTCs. If B1266 or B1267 exists, go to next step. If B1266 and B1267 do not exist, repair wiring harness between instrument panel ECU and body No. 2 ECU.
  8. Reconnect body No. 2 ECU to driver's side junction block and 25-pin connector B6 to body No. 2 ECU. Disconnect Gray 10-pin connector T5 from tilt/telescopic ECU (tilt/telescopic and instrument panel ECUs are disconnected). Recheck for DTCs. On models with navigation, if B1266 or B1267 exists, go to next step. On models without navigation, if B1266 or B1267 exists, go to step 10). If B1266 and B1267 do not exist, repair wiring harness between instrument panel ECU and tilt/telescopic ECU.
  9. Reconnect Gray 18-pin connector C133 to instrument panel ECU. Disconnect Blue 16-pin connector M3 from multi-display ECU (tilt/telescopic ECU and multi-display ECU are disconnected). Recheck for DTCs. If B1266 and B1267 do not exist, repair wiring harness between tilt/telescopic ECU and multi-display ECU. If B1266 or B1267 exists, reconnect Gray 10-pin connector T5 to tilt/telescopic ECU. Disconnect 22-pin connector A13 to A/C control assembly (A/C control assembly and multi-display ECU are disconnected). Recheck for DTCs. If B1266 and B1267 do not exist, repair wiring harness between A/C control assembly and multi-display ECU. If B1266 or B1267 exists, reconnect Blue 16-pin connector M3 from multi-display ECU and go to step 11).
  10. Reconnect 18-pin connector C133 to instrument panel ECU. Disconnect 22-pin connector A13 from A/C control assembly (A/C control assembly and tilt/telescopic ECU are disconnected). Recheck for DTCs. If B1266 and B1267 do not exist, repair wiring harness between A/C control assembly and tilt/telescopic ECU and multi-display ECU. If B1266 or B1267 exists, reconnect Gray 10-pin connector T5 to tilt/telescopic ECU. Go to next step.
  11. Disconnect connector from ECM (28-pin E5 connector on GS300, 26-pin E7 connector on GS400). A/C control assembly and ECM are disconnected. Recheck for DTCs. If B1266 and B1267 do not exist, repair wiring harness between A/C control assembly and ECM. If B1266 or B1267 exists, go to next step. If B1266 and B1267 do not exist, repair wiring harness between A/C control assembly and ECM.
  12. Reconnect 22-pin connector A13 to A/C control assembly. Disconnect 25-pin connector from B5 body No. 1 ECU. Check continuity of White wire between A/C control assembly connector A13 terminal No. 19 and ECM (E5 connector terminal No. 28 on GS300, E7 connector terminal No. 11 on GS400). If continuity does not exist, repair White wire. If continuity exists, replace body No. 1 ECU.
  1. Start engine. Check operation of tachometer and speedometer. If operation is okay, go to next step. If tachometer and speedometer do not operate, replace instrument panel.
  2. Disconnect 25-pin connector B6 from body No. 2 ECU. Disconnect 18-pin connector C13 from instrument panel ECU. Disconnect Gray 10-pin connector T5 from tilt/telescopic ECU. Check continuity of White wire between body No. 2 ECU connector B6 terminal No. 19 and instrument panel connector C13 terminal No. 11. (Scheme 2)and (Scheme 5). Check continuity of White wire, through connector and Blue wire between instrument panel connector C13 terminal No. 2 and tilt/telescopic ECU connector T5 terminal No. 6. (Scheme 5)and (Scheme 6). See WIRING DIAGRAMS.
  3. If continuity exists on both wires, replace instrument panel ECU. If continuity does not exist or one or both wires, repair wiring as necessary.
  1. Check operation of front and rear vertical seat motors. If operation is okay, go to next step. If seat front and back vertical do not operate, replace power seat ECU.
  2. Disconnect 25-pin connector R12 from left rear door ECU. Disconnect 22-pin connector P19 from power seat ECU. Disconnect 25-pin connector R13 from right rear door ECU. Check continuity of Blue/Orange wire between left rear door ECU connector R12 terminal No. 4 and power seat ECU connector P19 terminal No. 10. (Scheme 4)and (Scheme 8). Check continuity of Orange wire, through connector Blue/Yellow wire, through connector and Blue/Orange wire between power seat ECU connector P19 terminal No. 11 and right rear door ECU connector R13 terminal No. 5. See WIRING DIAGRAMS.
  3. If continuity exists on both wires, replace power seat ECU. If continuity does not exist or one or both wires, repair wiring as necessary.
  1. Check operation of sun roof. If operation is okay, go to next step. If sun roof does not operate, replace sun roof ECU.
  2. Disconnect 10-pin connector M5 from sun roof ECU. Disconnect 25-pin connector B5 from body No. 1 ECU. Check continuity of Orange wire between body No. 1 ECU connector B5 terminal No. 9 and sun roof ECU connector M5 terminal No. 2. (Scheme 2)and (Scheme 14). See WIRING DIAGRAMS. If continuity exists, replace sun roof ECU. If continuity does not exist, repair wiring as necessary.

Scheme 14

Scheme 14
Scheme 14

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