Car Flooded Won't Crank

Two weeks ago I was driving my 98 Riviera and the road had water on it. It was only about 4 to 6 inches deep until I hit a dip in the road and the water went up to over a foot. At this point, my intake sucked in water and killed the engine. I put the car in Neutral, got out, and started pushing the car backward. A Dodge van came by doing 40 and sent up a wake washing both me and the car off the road. A guy in a Jeep hooked his winch to my rear driver strut and pulled me out bending the strut, the passenger side of my exhaust, and my gas tank in the process. I pulled the plugs and turned the key to try to blow some of the water out. I noticed the ELC was running constantly, so I pulled the fuse. The starter was cranking until the battery died. I got someone to jump me, but at this point I got nothing when I turned the key. I had it towed to my local mechanic who changed the oil a few times and flushed the ATF. He is able to get the car to start by jumping the solenoid, but it will die after about five seconds. I believe this is due to security or there not being a signal sent for the fuel injectors to turn on, because the fuel pressure checks out. I believe my car to be mechanically sound. My mechanic believed the problem had to with VATS and said the car probably just needed to dry. Three days later I walked to the mechanic's and noticed the battery was dead. I had him charge it. He said the blower had been kicking itself on, so I removed the fuse. I tried to start it and noticed there was no issue with the security light, so I don't think VATS is the issue. Aside from the HVAC, all the accessories work. The key fob does what it should. The mechanic has put my car on the backburner, so I've been doing most of the troubleshooting myself. I had him test out a NSS he had on it, I've replaced the starter relay, now I'm at a loss. Now my mechanic is suggesting that it is the ECM and BCM. He says I should try putting them in rice. I want to make sure I have all the simple things covered before messing with those.

It's not throwing any codes. If it comes to it, can somebody tell me how to pull the BCM? I can't figure out how to get it off the white mounting plate. Sorry about the wall of text. I wanted to be clear, and I'm using my phone otherwise I would have put in paragraph breaks.

Welcome. So you know it's getting fuel, and you know there's spark (at least from the coils to the plugs). If the problem were VATS, there would be no turning over at all, not even a solenoid click.

The other thing we know is the battery died. Has anyone tried installing a fresh battery? I've been in situations where my car wouldn't start, and a jump wouldn't do the trick. It's worth a try, since you'll be needing a new one anyway.

It's possible the BCM or PCM were damaged from water submerging electrical connections, but I wouldn't just assume it. Try reading DTC codes with the key "on" with a fresh battery. The codes may tell you something. Good luck, and let us know what you find out.

There is no solenoid click when the key is turned now. The battery could be a possibility. Even though it is showing a full charge, it might not be putting out the cranking amps. I don't have a volt meter though. At the very least I could just try an unvented side post battery to test that out. Another possibility I'm thinking is that I might have a ground issue. Probably not important, but the Dashboard Accessory relay clicks when I turn the key. It probably always has, but I couldn't hear it. I have to work the next three days, so I can't get to it right away.

When a car gets wet, grounds can become a problem, and the Riv has a lot of them. Is the carpet wet?

Yes, the carpet got wet. It's dry in the front, but still wet in front of the backseat.

I'd take a close look at grounds too. Make sure the grounds are removed and cleaned. There is one near the radiator hoses that grounds the engine to the body, have both ends of the cable cleaned and make sure there isn't corrosion or slime where it contacts the body and block.

under the drivers seat is the body control module, might want to swap it out for a used good one.

Under the back seat, flip up the bolster and have a look. Did it get wet under there?

You will need a good battery to get the Riv electricals to behave if they are otherwise OK.

You will need an antibacterial cleaner such as Hibiclens to clean yourself up after removing/cleaning the wet interior parts of the car, especially if you were in an area with agricultural (chicken/pig farm) or industrial runoff.

You should consider stripping out the interior that got wet and cleaning the electricals/grounds. CRC makes electrical cleaning sprays that will help with this including "LectraMotive" and others - stop in at a NAPA or CarQuest, the counter person will probably know them all.

I bit the bullet today and bought a new battery. Still no crank, so I disconnected the battery so I know it will stay charged. I bought a can of LectraMotive as suggested. I'm going to change my sister-in-law's brakes today, so I'm going to have to wait until tomorrow to go hunting for grounds. According to my mechanic's Alldata, the BCM is under the driverside IP. It could be wrong, but I had found the starter relay to the left of what it said was the BCM as it had indicated. I think there was only about a cup of water under the rear seat, and that was away from the fuse boxes. I'll clean them along with all the electrical connections I find with the LectraMotive. I was told that it wasn't conductive, so I'll have to blow everything out with air duster once clean.

Of note: the PCM is located in the dash behind the glovebox. The water level shouldn't have reached that high.

I sprayed the fuseboxes and electrical connections with CRC QD (upon doing some research, I found out that Lectra-Motive wasn't plastic safe), and pulled the PCM. When my car got washed off the road, the glovebox had filled with water, so I thought the PCM might have gotten wet, so I decided to take it apart. After pulling out the screws, I had to pry the cover loose with a screwdriver. When it finally let go, I heard a whoosh of air come out of it that must have been in there since the Clinton administration. Still curious, I pulled out more screws and took out the board, and I found no water, no rust, and no corrosion. They are built well. I cleaned both ends of the ground wire that connect the body to the block, and I tightened the ignition wire to the starter after noticing it was loose. Still no crank. I haven't looked at the BCM yet. I guess it comes out similar to PCM. To be safe I'm going to unhook the battery and call it a day. Could the starter be bad even if you can jump the solenoid? I'm open to any further comments or suggestions.

sivarticus wrote:

I sprayed the fuseboxes and electrical connections with CRC QD (upon doing some research, I found out that Lectra-Motive wasn't plastic safe), and pulled the PCM. When my car got washed off the road, the glovebox had filled with water, so I thought the PCM might have gotten wet, so I decided to take it apart. After pulling out the screws, I had to pry the cover loose with a screwdriver. When it finally let go, I heard a whoosh of air come out of it that must have been in there since the Clinton administration. Still curious, I pulled out more screws and took out the board, and I found no water, no rust, and no corrosion. They are built well. I cleaned both ends of the ground wire that connect the body to the block, and I tightened the ignition wire to the starter after noticing it was loose. Still no crank. I haven't looked at the BCM yet. I guess it comes out similar to PCM. To be safe I'm going to unhook the battery and call it a day. Could the starter be bad even if you can jump the solenoid? I'm open to any further comments or suggestions.

Good catch on the lectramotive, I should have said more than I did, such as that LM was for motors/contacts and cleaning up those grounds. QD works. For that matter WD40 works as a drying spray but you have to get it off afterward like with denatured alcohol (dry gas).

At this point...

What I would do is draw a cartoon, on paper, of the car and shade in what got wet. So this does not turn into an endless hunt. Next I would check the wetted systems - that is, the electrical systems that are in the locations you shaded in on your drawing. For instance it sounds like your starter was submerged. SO - Consider getting a junkyard starter. People don't junk their cars over starters, so you are likely to get a good one at the pick-and-pull, or direct from a regular dismantler. If they are cheap enough get 2 at pick n pull; many parts stores (autozone) will test them for free. Between the one you have and the junk ones you will be able to build at least one good one.

Not sure what to suggest next because I don't want to poke around in the dark and I really don't want to put my foot in my mouth again -- but I have brought flooded cars back to life before (for myself never for sale). Each one has been a bit different. Sometimes itsa piece of cake and sometimes not worth it. What else can you tell me about this one?

Okay, I did what you had said about the cartoon and shaded everything in. I realized that a top view wasn't working since I had almost everything shaded. So, I drew two more pictures each a side view. These show that the water got half way up the dash on the passenger side, and once the car leveled off, about two inches from being level with the seat portion of the driver seat. I'm almost confident that the BCM didn't get wet. It might have gotten condensation on it though. Under the backseat I had found about a cup of water, but it must have entered on the passenger side even though I'd found it on the driver side.

I noticed that my security light wasn't coming on for bulb check when the key is turned to start. After doing some research, I found that it could be a problem with VATS. Previously I was content with the fact that it wasn't flashing or staying on after attempting to start, so I thought that ruled VATS out. I went through the whole process of measuring the resistance of the chip. I got 670 ohms which correlates to 681 ohms. I bought a 5 pack of 680 ohm resistors from Radioshack. I followed the write up on page 23 of the VATS thread. After I had the resistor wired in place, I read the resistance and got 570 ohms. Is this normal, or indicative of a problem? I tried the ignition and still no security light and still no crank.

sivarticus wrote:

I noticed that my security light wasn't coming on for bulb check when the key is turned to start. After doing some research, I found that it could be a problem with VATS. Previously I was content with the fact that it wasn't flashing or staying on after attempting to start, so I thought that ruled VATS out. I went through the whole process of measuring the resistance of the chip. I got 670 ohms which correlates to 681 ohms. I bought a 5 pack of 680 ohm resistors from Radioshack. I followed the write up on page 23 of the VATS thread. After I had the resistor wired in place, I read the resistance and got 570 ohms. Is this normal, or indicative of a problem? I tried the ignition and still no security light and still no crank.

If your resistors have 20% tolerance this would be normal, but inadequate for the job. You might need a better grade of resistor.

I finally decided that the TDM was the culprit, so I bought a VATS bypass module. I decided to go the ~$65 route instead of the $200 Newrockies route, so I bought the Bakerelectronix module with the quick disconnect option for added security. I looked up the wire diagram, wired everything, bypassed the starter enable relay, and it started. It was idling high, which I think is because of the exhaust. This matter is finally solved.

If the TDM got wet, this solution will fail when the corrosion in the wetted TDM causes other problems. I think you should consider finding and fixing the "root cause" so to speak.

I have the TDM unhooked. The bypass module replicates the 50hz to ground signal that the TDM sends to the PCM to enable the fuel injectors.

Got my car out of the shop today. I watched them make Frankenstein's monster out of my exhaust from the y all along to the passenger side muffler. I really wish I had a digital camera to show you their creation. I think they were so embarassed by it that they didn't charge me for it. I am thankful though, because I was expecting to pay around $500 for all the work they had done, but I only had to pay $175. The instant start and high idle went away and was replaced by me having to hit the gas upon starting after driving it. Afterwards, it idles fine. My airbag light is on, which I am fine with. After being stupid enough to flood it, I feel like my face is fair game should I crash it. I also have the ABS light and traction off light. My HVAC blows hot air at 60, and my rear shocks need to be replaced. I've seen threads here covering most of these problems. Thank you all for your advice along the way. I see trips to the salvage yards in my future.