mbella2000

HELLO ALL
I have a 97 corvette with 36,000 mi. Long story short..My damn a/c condenser under the passenger side began leaking 2 weeks ago. I had the fuse box cover off because of a blown wiper fuse (i thought it was blown) I left the cover off for 2 weeks as my ac condenser leaked all over the fuse box and the ecm which I cant believe is not sealed. Anyway the next week, my interior lights started flickering, my security light stayed on while driving, sometimes the starter would not engage due to the fuse box being wet or the ecm. Also now my abs light is now stuck on and my anti slip light is also stuck on. I checked the diag codes and I am getting a torque problem code on due to the anti slip light staying on the dash. I figured my ecm was shorted out since the water got into it. I purchased an ecm out of a 2000 vette with 10k on it. I put it in the car and the car didnt start. Didnt even turn over, just spring action. I was told i needed to change the resistance on my key from a 15 to a 2. Makes sense. I did this. I put key in and the car did nothing and the car steering lock noise that it makes when u insert the key did not come on.I had the ecm reflashed and still nothing. I put the ecm in again this time waited 15 mins and had the battery disconnected and now the steering column lock makes the unlocking noise its supposed to when the key is inserted and turned to on, the car starter now turns over but the fuel pump is not comming on to make the car start. When I put my old defective ecm back in, the car starts. can anyone explain what i am doing wrong? Why wont my car start. Everything is correct. Help!! Also why are my lights all stuck on my dash as in my security light flashing while im driving, my service soon light is on due to the abs light staying on and the anti slip light on. This all started when my ac started leaking onto the fuse box and ecm. I checked fuses and all are good. I checked relays and all are good Is my fuse box shorted? Is my ecm fried? Can my original ecm be fixed? I cant drive my damn car anymore due to all of this and I am at wits end. P.s my numbers on the old ecm match the new one.

One more thing. My wiper motor wwas just replaced and all of a sudden when I try and turn off the wipers, they stay on. They used to shut off for about 2 days, now I have to pull the fuse to get the wipers to stop going. Is there a relay I can check that may be bad or is my steering column wiper switch faulty. I cant believe a $25,000 corvette with 36k miles is having this problem. ANy help appreciated

Thanks for any info. My email is mbella2000@comcast.net or ill check this tomorrow. Thanks guys

Cobra R

The A/C condensor is in the front of the car and not even close to the ECM. A/C system does not have a substance to leak out and drip, freon turns to a gas once it is released from the system.

The ECM is pretty well sealed, what usually happens if there is any water intrusion, it happens in the connectors and causes corrosion.

I would check the battery for leaking acid. You may also have a bad battery cable and other damage to the wire harness if the battery has leaked acid onto it long enough. Otherwise, maybe a bad ground.

boosted_z06

If your talking about the control box in the passenger floor that is not a ECM (PCM) but is the BCM which controls other functions of the car, not the engine
The PCM is weatherproof and is behind the right wheel well.

If you swap the BCM or PCM they then have to be relearned to one another or the engine will not start at all.
Also if the PCM was changed you might also have to do a crank position relearn.

mbella2000

Thanks. I made a mistake its the evaporator under the passenger side dash. And the bcm (body control module is not sealed, It has openings in the corners where the water/freon liquid was leaking out of my evaporator. ALso How do I get the BCM to relearn? I dont understand. I have done all configurations. Help Thanks. I checked battery all is good. This all started when my bcm or fuse box got soaked by water comming out of the evaporator. my passenger side carpet was soaked, How do I get the computer to start with my car no and get it to "relearn". I have tried everything on this. No corosion on wires anywhere, Thanks

SpeedyZ

Your old BCM may not be bad. Are you sure you got all the water out of the old BCM? A lot of time when electronics gets wet they will freak out and do all kinds of weird stuff but not be damaged. It sounds like yours is not doing the same thing all the time which makes me think it may still be a little wet inside. It would be worth a shot to try to dry it out really good and try it again. I have never looked at a C5 BCM so I don't know about these, but from working on all kinds of other electronics on all brands of cars I have seen lots of time a little water cause lots of problems but once the part was dried out good it worked fine. If you can open the BCM case try compressed air to blow it out really well. Also heat it with a hair drier for 15 minutes or so but don't get it hotter than you can touch. Then after your pretty sure it is completely dry blast all the boards, chips, connectors and everything else inside the BCM with WD-40. You can leave the WD-40 on the boards, just shake out the excess. Make sure you blast under each chip, it takes way less than a drop of water under a chip to short the pins together causing the thing to go nuts. A lot of automotive computers are coated with a silicon type coating that keeps water from getting to the electronic components, but even then the connectors can get wet and cause problems. Just a thought, it can hurt anything to try drying out your old one, maybe it will work.

Good luck

mbella2000

Thanks for the response. so far yours has been the most helpful. You think like me. I actually dried out the old bdm with a hair dryer already and still the same problem. The check engine lights are pointing to a torque sensor which has to do with the anti slip light that is stuck on, now on the dashboard. Also I can feel a pull or drag now when driving the car with the light on, like the car thinks the car is sliding in the rain and making the anti slip kick in. Again this all started last week when my dash lights all went crazy coming on and off now just stuck on ever since my bcm and fuse box got wet from the evaporator leaking. I cant open the BCM as it is almost all sealed from the factory but GM left the corners slightly opened and the water got in. If i iinstall a new bcm which I did and i have the right key, i disconnected the battery, whcy wont the new bcm work? The car turns over but will not start. Someone here told me to get it to relearn..how does one do that? I am so aggrevated by not nowing what is going on with this? Im about to lose my job over this by not having reliable transportation. The steering column locked up the week before all this and had to go ini for the recall, now the wipers wont shut off when I turn the switch off , and the bcm is screwed up and the new one wont start my damn car? ANy other help out there? I used to work on cars and actually have done valve jobs on cars, ect. This has got me stumped!
Thanks

mbella2000

Any help at all?

MrEracer

If your BCM has been replaced and the relearn has not been completed the engine should fire off for 2 seconds and then shut down. If this is the case, conduct the following relearn process:
1. Turn the key on and leave it on for 11 minutes
2. Turn the key off for 30 seconds.
3. Repeat 1 and 2 above.
4. Repeat 1 and 2 above.
5. Turn on the key for 30 seconds.
6. Clear all codes.

This will match the PCM and BCM passwords so they can communicate with each other and the engine should start and run.

Shirl
SDRE

Bill Curlee

Try the relearn procedure! If that doesnt work for you, you will need to take it to the dealer and have them progran it.

Who replaced the wiper motor and did they clean out the cowl drains prior to installing the new motor? Your wiper motor seem like it is wet which can cause the same thing to happen.

Check these drains and make sure that they are clean:







Here is what they look like out in the open!



Here is what came out of mine!



Clear all of your codes and see if that clears any of the problems up. Sometimes just clearing the codes will fix the issue.

Bill C

mbella2000

Thanks for the info I will try to do this and see if it starts. Ps you said in number 6. clear all codes. Do I have to manually do this? I think I have before but just want to make sure this is a step that I take. When I put the new bcm in, my car runs for 1 second then shuts off, so I will try this method and turn ignition on and off and see if it relearns.

As for the wiper motor? I dont think clearing debris out of the engine compartment is going to let my wipers shut off. It seems as the switch on the column is not shutting off in the off position, possibly a relay not shutting off? i know there is a fuse for the wipers but is there a relay? No debris in my engine wiper compartment. my engine looks new. ANy help or suggestions? Also after my bcm got wet and disconnecting the battery a lot now my damn ac blows cold out passenger side but warm out middle. SOmetimes it blows cold both sides but mostly not all of a sudden. Is there a reset for this? This car ccant be having all these problems all in the same week. They all seem tied. Also after my bcm got wet my power trunk no longer works on the key or the dash. Im going crazy. ANy help on these or is it all tied to the BCM. By the way the guy that replied that said the bcm wouldnt be the problem with all my stuff being wrong, i think is wrong. He said the bcm controls emissions stuf ect, and not the check engine stuff and lights stuck on dash. With out the bcm the car wont start, the lights dont work no power no nothing so this does a lot more than emissions Anyway any suggestions on the air, bcm and wipers not shutting off? This is a nightmare for 3 weeks now and i drove the car only 3k miles and im out $1000 already and no car running

Bill Curlee

If your wiper motor is submerged in water it W I L L do all of the things that yours is doing!! TRUST ME!! ive been there!!!!! It is a simple check and doesnt cost anything.

As for the BCM, it controls just about everything inside the car. It is the traffic cop for all of the other modules. When you press the lock or unlock function on the FOB what do you think unlocks the doors turns on the lights, cancils the security system, makes the seat go to the ease entry position, ect. ect. ect. The BCM!!! If it is hosed the security system will cut off the fuel (She will start and shut down) The BCM also reads and translates the key code for the security system!!

If you are going to use the foreign BCM, you MUST do the BCM/PCM learn procedure!

I have been where your now and yes it SUCKS! I didnt have all of the knowledgeable people giving me the BCM Relearn Procedure:

If your BCM has been replaced and the relearn has not been completed the engine should fire off for 2 seconds and then shut down. If this is the case, conduct the following relearn process:
1. Turn the key on and leave it on for 11 minutes
2. Turn the key off for 30 seconds.
3. Repeat 1 and 2 above.
4. Repeat 1 and 2 above.
5. Turn on the key for 30 seconds.
6. Clear all codes.

This will match the PCM and BCM passwords so they can communicate with each other and the engine should start and run.

Shirl
SDRE

and I had to take it to the dealer to have the BCM programed.

Do the relearn procedure and let us know how it turns out.


BC

mbella2000

WOW THANKS TO ALL!!!!!!!!!!!. Getting my BCM to relearn did the trick. Man Thanks so much to BILL CURLEE AND MrEracer. You guys solved my bcm problem by my car not starting. I have 1 more minor issue. All my lights that were shorted out on my dash are now fine. My car starts up and drives with the new bcm installed after following the procedures. Heres the minor problem now.

I take it the old bcm was out of a wrecked corvette (2000). I bought it in a junkyard on the internet. After installing it, disconnecting battery and all that, I am now getting trouble codes from the old car showing up on my dash. I went into the diagnostics mode and pushed the reset on all of them. Now I am getting these flashing on my dash

1) shocks inoperable
2) service Ride control
3) Max speed 80 mph.

I pushed the reset button after going into the system by pressing options and fuel 4 times. I cant get these codes to go away now and they are on all the time. What am I doing wrong now? I disconnected the battery and waited 1 hour, and same thing. I pressed reset for all the codes and still nothing? Any more help? Ill have to send you a paypal payment for lunch Thanks

Dan_the_C5_Man

See my response to this post in your other thread..