LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 2001 >> Prius >> Repair and Diagnosis >> Body & Frame >> Body, Cab Control Systems >> Body Control Systems >> System Tests >> Test No. 1: All Power Windows Will Not Operate
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Test No. 1: All Power Windows Will Not Operate

  1. Check multiplex control system to see if Diagnostic Trouble Code (DTC) B1221 (Toyota hand-held tester) or DTC No. 21 (open door indicator light) exists. See MULTIPLEX CONTROL SYSTEMS - PRIUS article. If DTC B1221 or DTC No. 21 does not exist, go to next step. If DTC B1221 or DTC No. 21 exists, go to step  4.
  2. 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 power window operation.
  3. Check wiring harness and electrical connectors for Yellow wire between power window master switch and body Electronic Control Unit (ECU). See WIRING DIAGRAMS in POWER WINDOWS - CARS article. Body ECU is located at driver's side of instrument panel on the fuse/relay box and contains an 18-pin and 20-pin electrical connector. 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.
  4. Check driver door control system for trouble symptoms. See TROUBLE SHOOTING PROCEDURE (DRIVER DOOR CONTROL SYSTEM)  under TROUBLE SHOOTING. If no trouble symptoms exist, go to next step.
  5. Check body Electronic Control Unit (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.
  6. Replace body ECU with a known-good body ECU and recheck power window operation. If power windows operates 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.
scientia non olet · About LEMON Manuals