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Test No. 34: Passenger's Side Junction Block Electronic Control Unit Does Not Operate

  1. Note location of passenger's side Junction Block (J/B) Electronic Control Unit (ECU) at passenger's side of instrument panel, electrical connectors and terminal identification. See Figure.
  2. Ensure ignition is off. Disconnect electrical connector 3B, 3C and P6 at passenger's side J/B ECU. See Figure.
  3. Using voltmeter, check voltage between passenger's side J/B ECU electrical connector 3B terminal No. 3 and electrical connector 3C terminal No. 9 at passenger's side J/B ECU. See Figure. Also, check voltage between passenger's side J/B ECU electrical connector 3C terminal No. 9 and passenger's side J/B ECU electrical connector P6 terminal No. 18. See Figure. Voltage should be 9-14 volts. If voltage is not within specification, reinstall electrical connectors. Go to next step. If voltage is within specification, reinstall electrical connectors. Go to step  7.
  4. Check CUT fuse (30-amp), DOME fuse (10-amp) and DOOR fuse (20-amp). CUT and DOME fuses are located in fuse/relay box at driver's side front corner of engine compartment. See Figure. DOOR fuse is located in fuse/relay box at driver's side of instrument panel. See Figure. If fuses are okay, go to next step. If any fuse is defective, repair short in wiring for appropriate fuse. See WIRING DIAGRAMS . For additional wiring for power supply circuit, see POWER DISTRIBUTION article in WIRING DIAGRAMS and WIRING DIAGRAMS in REMOTE KEYLESS ENTRY SYSTEMS - RAV4 article.
  5. Check wiring harness and electrical connectors between GND1, GND2 terminals on passenger's side J/B ECU and ground connection. See WIRING DIAGRAMS in POWER DOOR LOCKS - TRUCKS (EXCEPT SEQUOIA) article. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector is defective, repair as necessary and recheck system operation.
  6. Check wiring harness and electrical connectors between battery and passenger's side J/B ECU electrical connector 3B terminal No. 3, and between battery and passenger's side J/B ECU electrical connector P6 terminal No. 18. See WIRING DIAGRAMS . For additional wiring for power supply circuit, see POWER DISTRIBUTION article in WIRING DIAGRAMS and WIRING DIAGRAMS in REMOTE KEYLESS ENTRY SYSTEMS - RAV4 article. Repair wiring harness or electrical connector as necessary and recheck system operation.
  7. Replace passenger's side J/B ECU with a known-good passenger's side J/B ECU and recheck system operation. If system operates properly, original passenger's side J/B ECU was defective. If system still does not operate properly, check wiring harness and electrical connectors for passenger's side J/B ECU for intermittent problem. Repair wiring harness or electrical connector as necessary.
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