2017 Outback 3.6R power liftgate fix

New outback (to me) with non functioning power liftgate

Liftgate just beeps but won't open when pressing the open button on the fob.

Tried the reset trick by disconnecting the battery and shorting the battery leads together to reset the system, didn't work.

Toyed with the option of converting to manual liftgate cylinders but we still need a functioning latch. The manual liftgate latch will not fit in the stock powered liftgate actuator position (non compatible mechanically).

Also tried bypassing the touch sensors in the liftgate but this did not help.

Disconnected the touch sensor connectors (two pin, left and right) and checked continuity across the sensors. Opening the liftgate (relieves pressure on the touch sensors) and both sensors should read 10k ohms. Remove the left sided lower touch sensor (two screws and a plastic plunge keeper that needs to be popped out). The  lower touch sensor has a mating connector for the upper touch sensor, so both are daisy chained together. The upper touch sensor does not come out easily, apparently it is glued in place and if removed, needs to be replaced (according to the FSM)

May spoof the system with a 10k ohm resistor across both touch sensor connectors. This is just for a test, as operating in this mode is risking someone (or something) getting trapped between the liftgate and the body)

BOJACK 1000 Pcs 25 Values Resistor Kit 1 Ohm-1M Ohm with 5% 1/2W Carbon Film Resistors Assortment

Amazon $15

A new liftgate actuator wasn't in the budget so opted to troubleshoot below. With parts and test equipment still came out ahead.

Latch and Actuator Tailgate (power Rear Gate)

Part Number: 63032AL000 $350

Remove the plastic access cover on the liftgate to show the innards on power up. Video shows the system searching for the home position and not finding it and defaulting to the liftgate latch open position. As a result, the system 'searches' for home, and not finding it, may leave the system in another state, such as unlatched

Video of liftgate actuator

The green 'sector' limit switch (with the lever pressed in, in closed position) defines the home position but if this switch is failing the system won't work.

Schematic of power supply and switches

One switch (OFF ON) is used to bump power on and off. The other switch (OPEN CLOSE) allows reversing the polarity of the motor leads and therefore motor direction. I only had two position switches DPST on hand so this is what I used. A single momentary DPST switch would work better, allowing momentary ON/OPEN ON/CLOSE with the default position OFF (center).

Rigging an external power supply at 12 volts on current limit (guessed at 3 amps) with manual switches to simulate the battery and control module allows actuating the liftgate open (fully counterclockwise on the gear) and closed (fully clockwise)

Power supply doesn't have to be fancy, just the basics but this is what was available (don't need USB)

DC Power Supply Variable, 0-32V 0-10A Switching Bench Power Supply with 20W USB & Type-C Quick-Charge, Encoder Coarse & Fine Adjustment Knob, Output Switch, 4-Digit LED Display - SPS-3010V

https://www.amazon.com/dp/B0DDPVDWPZ?ref_=ppx_hzod_title_dt_b_fed_asin_title_0_0

Video of bench power supply testing

Replacing the power liftgate switch.

Drilled out the "sector" limit switch aluminum post using a 3/16" bit. The bit slid around requiring several position changes and finally tearing off the remaining bit with linemans pliers. Then used the pliers to shear the post leaving the aluminum nub behind which popped out easily. Now we have a 0.24" thick switch body and a 0.07" hole that needs to be drilled out to 1/8" to allow a fastener to secure the new switch. Have to remove the motor assembly (3 bolts) to allow the M3 fastener to fit.

M3x12mm hex bolt is 0.118" which should just fit inside the mounting hole of the switch (0.12")

2240PCS Metric Screw Assortment,M2-M5 Metric Screw Kit, Hex Socket Metric Bolts, Metric Machine Screws 12.9 Grade Alloy Steel,Black Zinc Plated,Free Allen Head Wrench

Amazon $24

New limit switch.

Panasonic ABJ363861 SWITCH SNAP ACTION SPST-NO 0.1A 125V

$16 shipped from DigiKey

Used solder sleeve to hook it up.

Replacing the limit switch allows the system to detect the home position with the orange pawl on the gear engaging the green limit switch lever and closing the limit switch contacts.

New limit switch

Initial position of the actuator gear was max clockwise after bench test (which is where the system had left it after the failed initialization due to the bad switch). This position caused two issues

1. The boot sequence no longer ran the initialization the same

   1. The system just beeped three times. No motor activity

   2. Why isn't known

2. The manual unlock lever doesn't work in this position since the actuator lever is forcing the latch into the lock position

3. Used the power supply and switches to run the actuator gear counterclockwise just enough to be able to manually open the latch

4. Cycling the system power (battery disconnect) boots the system into a good state and the working limit switch is able to allow the system to find home, which consists of the system resting state with the limit switch closed (limit lever snapped shut)

Test after resetting the system after reconnecting the battery

This is the first powered liftgate opening test after replacing the limit switch

Video

Hope this helps. Bonus points if you have read this far down and are still awake.

Edited Friday at 11:40 AM4 days by 89Ru