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Test No. 17 - Instrument Panel Communication Bus Shorted Problem: Testing

  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.
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