I ran into the same problem. I left my car for a couple of weeks while on a trip and noticed the carpet was waterlogged. I spent some time vacuuming the water and removing the TCM. I still have it out of the car drying. What's a good product to clean the contacts with, if you know. Also, I noticed the oil pressure red light blinking and the tach doesn't work either. I suspect something wrong with the instrument panel or a module.

 

For me it was the CCM module. It's underneath the carpet and if it gets waterlogged, unfortunately you will probably have to replace it. You can buy them from a junk yard. The drain around the battery is the known problem, here. There is somewhere else on the forum that talks about it. That is how the water got in, through the dash, from a clogged battery drain, so it might have gotten your tach wet on the way in? I did not have that problem, but the CCM might be related. Might ask around. Good luck!

 

The problem is more than likely in the the wiring harness or in the interior control module that is located in about the same position as the tcm only on the driver front floorboard rather than the passenger floorboard. If you do a search of my posts you will find details about what and where to look within the wiring harness's but in a nutshell you need to unwrap the wiring harness that runs to both the icm and the tcm from the firewall all the way around to where they go into the modules and where they run under the carpet under the seats. located in the harness are splices with a rubber boot over them they are very small and you must seperate the wires to find them. the rubber boot holds water inside of them causing them to corrode and fall apart. this will cause all types of problems. there are two or three located in the harness along each door sill area and a couple more under the drivers seat area and under the passenger seat area.

 

Thanks, I'm tempted to use a box cutter to cut the carpet sections out so I'm constantly wrestling with them.

 

Unbelievable! After getting the TCM and CCM dried out as well as both footwells, I hooked everything back up, cleared the P0600 codes and fired the car back up. Everything works! Did a test run and the car ran normally. Granted, it's a little ratty right now, but functually it's fine and I didn't have to shell out any money other than for some tin snips and box cutters. My wife thinks I'm a genius now that I fixed the car instead of shelling out $$$ to a dealer.