My 2000 Altima accumulates water in the evaporator box and leaks onto the passenger side floor. The car started running rough and the Service Engine Soon light came on and the car cut out. When the car sits overnight it starts right up and idles fine until it warms up and then it starts to misfire and cuts out again. I had the car towed to the Nissan Dealer where I bought the car and they diagnosed that the water from the evaporator box leaked into my ECM and fried it. Of course they want a rediculous amount of money to replace the ECM and fix the leak problem in the evaporator box. They told me that the ECM alone was $885.00 w/o installation, and to do the whole job it would be about $1800.00. I have found a website that sells new replacement ECM's with a no questions asked 1 year warranty for $175.00 plus $10.00 for shipping. How difficult is it to get to the ECM in my car and what's involved to replace it? Also Nissan told me that the reason the evaporator box is leaking is because leaves accumulate on the screen under the hood where the outside air comes into the blower motor, and get sucked in when they become crushed. This debris become wet when A/C is ran and then clogs the drain tube. What is involved in removing the evaporator box to clean it out and can I prevent this from happening again? Any help or advice is greatly appreciated.

Thanks.

You dont need to remove the Evaporator to solve this problem. you can use a small screw driver and break up the debris from the drain hole on the front of the fire wall then remove the blower motor and reach in and pull out any remaining debris. To remove the evap you would have to have the freon removed so you could disconnect it. after you break up the debris with your screw driver you can pour a small glass of water in from the blower area down along the evap to rinse it out and test to see if you go it cleared out. The ecm is at the base of the dash on the floor infront of your center console.

oh one thing your need to take into consideration if you have chip keys[NATS] you will have to have those keys programmed to the ecm before it will start. this can only be done by the dealer for security purposes. Having it so only the dealer can get the nats consult card is part of the antitheft security [not just anybody can get the cards and program anyold keys to your car].

Thanks for the info. Today when I came home from work I decided to pulled the trim panel that covers the ECM and see what was involved in removing it. While I had the cover off I came up with a brainstorm idea that I would try to dry it out with a blow dryer and see if it it made any difference in the way the car ran. I figured what the heck, it can't make it any worse than it already is. I put the dryer on the floor about 12" away from the ECM and set it to high and let it run for about 15 minutes, then shut it off and started the car. The car started right up and the service engine soon light was no longer lit. I drove around the block to make sure it wouldn't stall. It ran fine so I decided to take it out on a main road. I drove for 20 minutes and even stopped for gas, and the car ran like the day I bought it. I brought it back home,closed all the windows and ran it with the heater on high postion for about 25 minutes through the upper and lower vents. When I opened up the door on the car it was like a pizza oven inside. This was an attempt to dry out the evaporator box and any moisture in the ductwork. I went back out about 2 hours later and started it up and drove it another 25 minutes with no problem. Now my next step is to get the drainage problem in the evaporator box resolved and hopefully I will not have any more computer problems. So far I'm feeling pretty good that I didn't hand over $1300.00 to the dealer for a new ECM. Wish me luck. :ylsuper

I think you'll be alright since you got it running ok after drying it out. usuallky what happens is the water causes the unit to short internally and burn up components on the circuit board. But in some cases the moisture only gets to the connector and cause contact between the pins in it ,not really causeing any damage but making the computer thoroughly confused. glad to hear it was only a superficial wound.

Okay I'm ready to tackle the drainage problem, how do I get to the blower motor? Is it from under the hood or from under the dash?

Thanks again for all your help.

its under the dash near the glove box. there should be three screws holding it up into the box. you may need to remove a portion of the glove box assembly in order to get it out. but you can see it from the bottom if you look up from the right foot of the passenger.

Thanks, I'm going to tackle it tommorrow.

Thanks for all your help.

Well I pulled the blower motor yesterday but it was clean. I wound up pulling the evaporator unit out of the car. The box had 3 inches of water in it and was loaded with leaf particles, small twigs, and a layer of black sludge on the bottom of the box(probably from decomposition of leaves and dirt). The drain hole was clogged solid from the sludge. Once I cleaned it up, unplugged the drain hole and blew all the crap out of the evaporator itself, I reinstalled everything and recharged the A/C system. The car runs great, seem to get colder than before, and the water now drains out like it's supposed to instead of filling up the evaporator box and draining itself onto my floor and shorting out the ECM. The whole job from start to finish took me 2 hours. My Nissan Dealer told me it would be an eight hour job and cost $600.00 plus tax to do. Mmmm.............:rolleyes