Test No. 21: 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. Auto up or down function may also be referred to as the one touch power window system.
- Check power window master switch. See POWER WINDOW MASTER SWITCH under COMPONENT TESTS. If power window master switch is okay, go to next step. If power window master switch is defective, replace power window master switch and recheck operation of auto up or down function.
- Check passenger's side Junction Block (J/B) Electronic Control Unit (ECU) for proper voltage and input signals. See PASSENGER'S SIDE JUNCTION BLOCK 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.
- Replace passenger's side J/B ECU with a known-good passenger's side J/B ECU and recheck operation of auto up or down function. If auto up or down function operates properly, original passenger's side J/B ECU was defective. If auto up or down function still does not operate properly, check wiring harness and electrical connectors for passenger's side J/B ECU and power windows for intermittent problem. See WIRING DIAGRAMS in POWER WINDOWS - TRUCKS article. Repair wiring harness or electrical connector as necessary.