Sliding Doors Not Working 

🚗 2009 Toyota Sienna 

• Both sliding doors are inoperative from non of the switches.
• No sliding door chime is heard neither.
• Main PSD switch when pressing it on/off doesn’t make a difference in sliding door operation.

🩺 Diagnosis

• Checked for codes.
  • No codes.
• Using a scanner (active test), tested operation of latch mechanisms, door PSD motors.
  • All good.
• Live data showed all switches operate properly, including touch sensors, except the Main PSD switch.
  • When the switch is in out position (with orange stripe on the top visible), it enables power function of the sliding doors.
    • Live Data for Main PSD Switch should display “ON”.
  • When the switch is pressed in, it disables automatic operation allowing only a manual sliding door operation.
  • When I pressed on it, it didn’t change a value from OFF to ON. It stayed OFF, disabling automatic function.
    •  
• Bad switch?
  • Main Power SLiding Door (PSD) Switch is a simple latch switch. 
  • Wires for the switch are Pink and Red/Green.
    • Pink wire goes to both the LH Sliding Door ECU and the RH Sliding Door ECU (pin 6, Pink).
    • Red/ Green wire goes only to the RH Sliding Door ECU (pin 5, changes to Red/WHT).  
  • When the switch is pushed in (OFF), pink should have a constant 12V which disables the automatic door function.
  • When the switch is in the out position (ON), pink and red/green wires become connected through the switch, and RH Sliding Door ECU starts duty cycling the circuit with 25Hz 0V-12V square wave signal.
    • Then, both RH and LH Sliding Door ECUs see this square signal as a green light for enabling automatic function.
    • 
  • Switch can be jumped with a simple wire for testing purposes.
    • Jumping it didn’t produce a square signal, nor the scanner’s “live data” changed to ON.
  • Checked the continuity between pink and red/green wires of the Main PSD Switch and  pins 5 and 6 of the RH SLiding Door ECU. No problem there.
    •  
  • I was ready to condemn the RH Sliding Door ECU, but decided to see what will happen if I apply a 25Hz 0V-12V square wave signal to the pink wire. 
  • For that I used my AutoSim Waveform Generator.
  • I didn’t have 25Hz signal available in my options menu, the closest was 30Hz, but that worked like a charm anyways.
  • Scanner’s live data immediately showed Main PSD Switch as ON, and both sliding doors started working properly.
    • 

Now, I was sure that there are no other issues with the sliding doors’ mechanisms, and told the customer to replace the RH Sliding Door ECU.