Trunk lid won't open

[jimmyp16x]

My 05 Avalon was at the dealer for an oil leak. They warranteed the problem since it had reoccured from a previous warranty claim. According to them the engine was pulled to correct the problem. A week after we got it back we noticed the trunk lid wouldn't open from the button on the dash or with the smart key. The button inside the glove box is on. Only way to open the trunk is with the pull handle through the back seat. It acts like a blown fuse but the manual doesn't list a fuse at all for the trunk lid release even though there must be one. The dealer says they didn't cause the problem and wants to charge a service charge for repairs. I haven't been pleased with their service so I don't want to go that route yet. Any ideas?
Thanks

[TedL]

In no particular order.....
Try the online owners manual for your year, or a later year, looking for fuse location.
Try looking at each of the several fuse block locations. The covers will generally list what's within, on the outside or inside of the cover.
Pull each fuse in every (starting closest to driver's seat) and inspect/test for failure.
Look for disconnected wire (from work done).

[inov8]

It seems too much of a coincidence that the trunk release stopped functioning just after the engine work, but it's not impossible.

There are no fuses dedicated to the trunk release circuit. The 3 fuses in the circuit all protect other functions as well. If a fuse is blown, I would expect you to have other malfunctions. Might be worthwhile to check every function you can think of.

The 3 fuses are:
ECU-B (10Amp)
ECU IG #1 (7.5Amp)
ECU-ACC (7.5A)

Assuming every other accessory seems to work OK, the first thing I would check is if 12V is reaching the release motor, which is part of the lock assembly in the trunklid. The trunklid liner can be removed with a door panel removal tool; it is held in place with the same kind of blind clips. You will find a connector plugged into the trunk release assembly. Wire colors are Black (motor), Black-white (ground), and White (trunk unlocked indicator). Each time a helper pushes the switch located next to the fuel door release switch, there should be a DC voltage between the Black and Black-white wire connector pins for a few seconds. You can also measure between the Black and a chassis ground point.

If no DC voltage, the problem is in the body computer, or body computer wiring, since none of your electrical trunk opening methods work, including the key fob.

I checked the factory manual step-by-step instructions for engine removal, trying to see if anything gets disturbed that could affect the trunk release circuit. The only commonality I found is the main engine firewall connector located behind the glove box. Body computer ground connectors are also located in this area and could have been disturbed.