Yesterday I carefully detailed the engine....low pressure water and dried everything. Then drove it a couple of miles. This morning it won't start. Cranks, but won't catch, like it's not getting fuel. Barrowed OBDII from auto parts place. Says it isn't connected (?) , so unable to retrieve any error codes. Only other clue is, factory lock/unlock transponder, while it works, horn doesn't honk after locking (like it would yesterday. Also, buzzing sound heard from behind engine when I popped the hood....lasted 30 seconds. Also has aftermarket ECU G4x installed. I didn't install it or know where it's located. Is that where I should connect the OBD reader?

 

Lesson learned, never wash ANY modern engine with water.

If your computer was dirty do you wash it off with running water?

Engines are NOT waterproof, the electrical harnesses are designed to be splash resistant but were never designed to be flooded with water.

You got something wet, my best advice is pull the car in the shop, get the heat turned way up, provide plenty of airflow and cross your fingers that whatever got wet will dry out quickly.

As for not being able to link to the standalone with an OBD2 scanner, typically there will be a little pigtail harness directly off the ECU with a USB port to connect directly to a computer. You will also need the software from the manufacturer. I've never used those ECU's so I have no idea what it will entail, I recommend checking out the manufacturer's website.

The ECU is probably mounted somewhere near the factory ECM location though.

The "buzzing" sound might just be a stuck ABS relay, see if the noise is coming from a small motor attached to the ABS valve block right below the brake master cylinder.

 

First, I appreciate you taking the time to reply, however as I said, I was very carful where the water the water went. While some splashed on electrical components, it was minimal and I dried everything I could reach, including using a q-tip. Add to that, I drove the car for around 15 minutes afterword. I doubt anything was wet after that and there's nothing left to dry.
As far as using the OBD to pull codes, when an aftermarket ECU is added, does that make the factory ECM location unusable and the only way to pull OBD2 codes is from the aftermarket ECU?

 

Typically yes, if it's a standalone unit. I would take the glove box off and the right footwell kick panel and see if the stock ECM is still there or not.

 

So, on a hunch, I disconnected the neg battery terminal, waited a few minute, reconnected it and it started up on the first try! In the morning I'm going to hunt for the ECU behind the glove box. Thanks!