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Test No. 4: All Power Windows Will Not Operate

  1. Check D/PW fuse (20-amp) and P/PW fuse (20-amp). These fuses are 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 in POWER WINDOWS - CARS article. For additional wiring for power supply circuit, see POWER DISTRIBUTION article in WIRING DIAGRAMS. Body ECU is located behind driver's side of instrument panel and contains 18-pin and 25-pin electrical connectors. See Figure.
  2. Check AMI fuse (7.5-amp) and GAUGE fuse (7.5-amp). Fuses are 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.
  3. Gain access to body ECU. Body ECU is located behind driver's side of instrument panel and contains 18-pin and 25-pin electrical connectors. See Figure. It may be necessary to remove instrument panel for access to body ECU. For servicing of instrument panel, see INSTRUMENT PANEL under REMOVAL & INSTALLATION in appropriate MANUAL A/C-HEATER SYSTEMS article.
  4. Turn ignition on. Using voltmeter, check voltage between body ground and IG terminal (Red/Black wire) at body ECU. See Figure. Voltage should be 9-14 volts. If voltage is not within specification, turn ignition off. Go to next step. If voltage is within specification, turn ignition off. Go to step  9.
  5. Check ignition relay. See IGNITION RELAY  under COMPONENT TESTS. If ignition relay is okay, go to next step. If ignition relay is defective, replace ignition relay and recheck power window operation.
  6. Check ignition switch. See IGNITION SWITCH  under COMPONENT TESTS. If ignition switch is okay, go to next step. If ignition switch is defective, replace ignition switch and recheck power window operation. See IGNITION SWITCH  under REMOVAL & INSTALLATION.
  7. Check wiring harness and electrical connectors between body ECU and ground connection. See WIRING DIAGRAMS . For body ECU electrical terminal identification, see Figure. 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 power window operation.
  8. Check wiring harness and electrical connectors between battery and body ECU. See WIRING DIAGRAMS . For additional power supply, see POWER DISTRIBUTION article in WIRING DIAGRAMS. 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 power window operation.
  9. Check power window control switches. See POWER WINDOW CONTROL SWITCH  under COMPONENT TESTS. If power window control switches are okay, go to next step. If power window control switch is defective, replace power window control switch and recheck power window operation.
  10. Check wiring harness and electrical connectors between power window control switches and body Electronic Control Unit (ECU). See WIRING DIAGRAMS in POWER WINDOWS - CARS article. For body ECU electrical terminal identification, see Figure. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector are defective, repair as necessary and recheck power window operation.
  11. Check body ECU for proper voltage and input signals. See BODY ELECTRONIC CONTROL UNIT  under PIN VOLTAGE TESTS. If proper voltage and input signals exist, go to next step. If proper voltage and input signals do not exist, repair as necessary and recheck power window operation.
  12. Replace body ECU with a known-good body ECU and recheck power window operation. If power windows operate properly, original body ECU was defective. If power windows still do not operate properly, check wiring harness and electrical connectors for body ECU and power windows for intermittent problem. See WIRING DIAGRAMS in POWER WINDOWS - CARS article. Repair wiring harness or electrical connector as necessary.
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