I have a 2003 Toyota Camry XLE V6 automatic and I can't get it started. The last time the engine was running was 4/4/17, it last tried to turn over with in Aug/Sept. 2017. I had very little car repair/mechanical experience before this ordeal and although I've enjoyed learning about the inner workings of my vehicle, I really just want to get it running again.
It all started last April 4th 2017, went to the Golden State Warriors game (3 rows back) had a great time, even met Steph Curry’s wife Ayesha! Me drink many beers, had such a good time I left keys behind, called the Arena, but didn't here anything back, thinking the keys were lost I called Toyota and was told a new master key would cost close to $700.00. Holy Moly! I decided to call a locksmith and he said $150 over the phone, but after looking up my model in his reference book he said he would need to reflash a chip (IC900) on the ECU (89666–33430) and program a new key to it, estimate went up to $275.00. I figured it was still worth it. It's now been almost 10 months since the Camry has started...
This is everything that happened afterwards:
The Oakland Coliseum called a few days after the locksmith debacle and told me the found my keys. Tried to start the car but it would not turn over. It attempted but wouldn't start. Checked battery,it was low, recharged and tried using power boost jump starter, nothing...
1. Locksmith said he was having trouble reflashing the IC900 chip, he damaged the CPU circuit board with a screwdriver pen trying to clean off the connections to the chip, he said he'd come back to finish the job, never saw him again, filed claim against his insurance & settled.
2. A buddy of mine recommended his locksmith friend check it out, he plugged a key programming tool into the OBDII, couldn't reprogram a master key.
3. Had the vehicle towed to two separate Toyota dealerships for a diagnostic check ($150 each + tow), first said to replace the ECU and reprogramming $1,800.00, second said another option would be to get a used/remanufactured CPU and have a CPU tech reprogram. Programming range $150-$200 + ECU range $50-$400
4. Purchased ECU off eBay ($75) my regular mechanic, referred me to a tech that specializes in Toyota programming. Paid $200 for putting the ECU into learning mode and registering my master key to it and two spares. Installed the reprogrammed ECU, car would not start, attempted to turn over, but would not start. Tech said there may be something else wrong with the ECU.
5. Found a remanufactured to OEM specs ECU online $400, had same tech reprogram $150, he gave me a discount. He also mentioned that he spoke to a Toyota engineer that said my model may have an immobilizer module (89870-AA010). I took apart the mid-console, passenger/driver upper/lower dash trying to locate this module, but had no luck. I did find 89730-AA010. I called Toyota provided my VIN and was told that my model did not have immobilizer module 89780-AA010. I put the 2nd reprogrammed ECU in and nothing, a few clicks and that's it, the engine didn't even make a sound....This was 1/27/18.
I don't know what to do next, I'm stuck. Any helpful insight or knowledgeable advice would be much appreciated...

I've posted pics in an Album, 2003 Camry XLE

Questions I have,

1. Does the theft deterrent module need reprogramming? PN# 89730-AA010
2. Is there anyway to scan the car and see what else may be happening?
I'm pretty sure I need a new battery...

I confirmed a new battery was needed, upon further inspection of the battery terminal connections, I decided to replace them, however I cut the negative terminal off and now with my new replacement connectors the negative cable is too short. I went to interstate battery store and they advised me to replace the cable, or connect the cable somewhere else on the chassis.

The negative battery cable cable splits in two, I have easy access to one end, however the second cable snakes into the engine compartment and I can see where it’s connected to on the chassis, but not sure I can access it, even if I could I’m not sure I have the right parts to remove it, let alone reconnect it...pics attached...

I bought a battery harness splice kit and replaced the corroded terminals, parts cost less than $25, available at your local auto parts store,. East Penn manufacturing has a great how to video on YouTube.

I installed the new battery, interstate (group 35, Fit 3)(Costco) $82 out the door with old battery swap. Checked the connection and had solid power.

Got inside the Camry, no key in ignition, the light was solid.

I put the master key in the ignition and the security light started blinking.

I turned the key to on position, light still blinking.

1st attempt to turn engine over and Abracadabra Alakazam, the engine turned over and started!

1st time just shy of 11 months. I should have done this after I purchased the 1st ECM off eBay and programmed it. Possibly could have saved myself $550.00, but that's neither here nor there, the Camry is up and running g and I'm a happy Camry owner On the Road Again!

Now I just have to figure out what this part is (17805-20040 INOAC PP/PE) seems to be a reservoir that's disconnected...

It does, I found where it should connect to, not sure how or why it came off...

I filled up the tires, went down to the local autozone and got some engine treatment fluid and mixed it with a fresh tank of gas and went on a 25 mile ride. Everything seemed fine but the VSC / TRAC OFF light came on, I tried pushing the TRAC button but it did not turn the light off. These lights have been on since I’ve owned the car. I’m going to try an research what they mean and why they came back on...