Flooded Z
 

*Sorry for the long post*

So in a ditch effort to save my car from completely flooding I drove my car through our flooding parking lot to higher ground. The water I drove through was about a foot and a half. Thankfully, no water got inside the car. I parked my car for several days to let it completely dry up and crossed my fingers that nothing got damaged.

4 days later I had to drive about 25 minutes to work. Keep in mind that I have not had a single issue with my car at all before the flood. No problems starting, running, shifting etc. Car ran great!

About 20 minutes into my drive I pull out onto a highway (nice and easy) and it will not shift out of 1st gear. I pull over turn it off and start driving again, this time it gets to 3rd gear and wont shift anymore. I attempted to manually shift it into 4th gear, but it just beeped at me and stayed in 3rd gear. I put it back in automatic mode then all of a sudden it slams into 1st gear by itself. I coasted it into a parking spot and called for a wrecker to take it to Nissan.

A week later Nissan is telling me that they do not see any signs of water damage. They say that the intakes are dry. When I questioned them that wouldn't it be dry anyway since it has now been over a week since the initial flood the service manager said that they would have seen something. He said they checked the dipstick and found no water in the transmission fluid.

He proceeded to tell me that his trace team found that the Valve Body was damaged, but it was mechanical and not caused by the flood.

Listed are the codes they where able to pull

2012 Nissan 370z 7AT (Que the manual drivers hate :facepalm: )
About 75,000 miles

P0420 - Catalytic converter (previously changed to test pipes)
P2A03 - Another exhaust code
P0500 - Vehicle speed sensor?
P0720 - Powertrain control module
C1711 - Data From Rear Left Transmitter Cannot Be Received
B2562 - Engine Control Module
B1018 - Seat assembly problem
C1109 - Anti-Lock Brake System

So because Nissan is saying that the issue is mechanical and not due to water damage insurance is refusing to cover the cost. I am now having it towed tomorrow to a different mechanic for a second opinion.

Can anyone give me any insight as to what it might be? It just seems to be too coincidental for this to have happened right after driving through flood waters. I feel like Nissan just looked at the dipstick and air filters to rule out water damage. The service manager said the valve body fails all of the time, but wouldn't I have started to notice something - slipping gears, hearing something etc. before?

Thanks for all of your help!

With all the different DTCs, I suspect a wiring problem. A corroded connector would be high on my list of possibilities.

I agree with SouthArk.
Even though the mechanical side looks good and unharmed, it doesn't mean the electrical side is in proper condition. It sounds like the dealership only bothered to do a quick engine look and skip over the communication system (seems a bit lazy of them, but w/e).

Unless they have someone who has been around the block, dealerships are notorious for not being able (or as stated above, to damn lazy) to track down electrical gremlins.

Code Definition as per FSM:
C1109 ABS module low voltage
B2562 BCM module low voltage

As you can guess, low voltage can create many additional false codes.

Check the connections on the battery and measure the battery voltage. it should be more than 12.5 volts.

Since the starter, alternator, and other system were underwater, internal corrosion may cause low voltage.

Since the water was 18" deep, I would check for water inside the car. On the passenger side foot well, pull back the carpet and pull up the insulation and see if it is wet. I would suspect it is.