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Test No. 26: Auto Up Or Down Function For Driver's Side Front Door Power Window Does Not Operate

NOTE: Auto up or down function controls automatic operation of power window. When power window switch is pushed completely downward and then released, or pulled completely upward and then released, the power window will fully open or close.
  1. Check ECU-IG fuse (7.5-amp), PWR No. 1 fuse (25-amp) and ECU-B fuse (7.5-amp). ECU-IG and PWR No. 1 fuses are located in fuse/relay box at driver's side of instrument panel. See Figure. ECU-B fuse is located in fuse/relay box as driver's side front corner of engine compartment. 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 - TRUCKS article. For additional wiring for power supply circuit, see POWER DISTRIBUTION article in WIRING DIAGRAMS.
  2. Note location of driver's door Electronic Control Unit (ECU). See Figure. Driver's door ECU is located on driver's door and is incorporated into the power window switch assembly.
  3. Note electrical terminal identification on electrical connector for driver's door ECU. See Figure. Turn ignition on. Using voltmeter, check voltage between terminals No. 13 (White/Black wire) and No. 21 (Black/Red wire) at electrical connector for driver's door ECU. Voltage should be 10-14 volts. Turn ignition off. Go to next step.
  4. Ensure ignition is off. Disconnect electrical connector at driver's door ECU. Using voltmeter, check voltage between terminal No. 13 (White/Black wire) and terminals No. 23 (White/Red wire) and No. 25 (Blue/White wire) at electrical connector for driver's door ECU. Voltage should be 10-14 volts. If any voltage is not within specification, go to next step. If all voltages are within specification, reinstall electrical connector and go to step  7.
  5. Check for open in wiring harness and electrical connectors between ground connection and terminal No. 13 (White/Black wire) at driver's door ECU. See WIRING DIAGRAMS . For additional wiring, see WIRING DIAGRAMS in POWER WINDOWS - TRUCKS 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 operation of auto up or down function.
  6. Check wiring harness and electrical connectors between battery, ignition switch and driver's door ECU. See WIRING DIAGRAMS . For additional wiring for power supply circuit, see POWER DISTRIBUTION article in WIRING DIAGRAMS and WIRING DIAGRAMS in POWER WINDOWS - TRUCKS article. Repair wiring harness or electrical connector as necessary and recheck operation of auto up or down function.
  7. Check driver's door ECU for proper voltage and input signals. See DRIVER'S DOOR 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 operation of auto up or down function.
  8. Replace driver's door ECU with a known-good door ECU and recheck operation of auto up or down function. If auto up or down function operates properly, original driver's door ECU was defective. If operation of auto up or down function still does not operate properly, check wiring harness and electrical connectors for driver's door ECU for intermittent problem. See WIRING DIAGRAMS in POWER WINDOWS - TRUCKS article. Repair wiring harness or electrical connector as necessary.
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