The past two times I've driven my 2002 I've got the Reduced Engine Power Service AH/TC. The EBCM was already repaired a few years ago and I dont think that is the issue.

When the message popped up EVERYTHING in the car failed. Radio shut off, guages stopped working, door controls died. I restarted the car and drove home in normal mode. When I got there the driver's side door controls still did not work and I could not roll up my window. A few min later it worked.

I checked the codes.......and there are alot of them, most are history.

I'm leaning toward a ground, battery issue. Any suggestions where to start would be great.

PCM
P1626H

TCS
U1301H
C1226H

BCM
U1255U
U1096H
U1016H

SDM
U1301H

IPC
U1255H
U1016H
U1064H
U1040H
U1176H
U1088H
U1160H

RADIO
H1064H
U1016H
U1096H

HVAC
U1064H
U1096H
U1160H
U1255H
B0361HC

LDCM
B2282H
B2284H
B2264H
U1064H
U1096H

RDCM
SAME AS LEFT DOOR BUT 1 NUMBER HIGHER

SCM
U1300H
U1255H
U1016H
U1064H

RFA
C2115HC
U1255H
U1096H

 

Nothing done to the car recently.

New clutch went in about 7 months ago. Its just an intake/exhaust car with long tubes and a dyno tune, but all of that work was done years ago.

Just remembered that recently, while driving the doors will randomly lock themselves. This is after it already did the auto lock at 12mph.

I'm leaning toward a bad ground. I'm working on the two front ground connectors now. Going to test the battery and pull battery tray to take a look at the wiring under it.

 

All of my grounds looked pretty clean, but I cleaned and greased all of the connections. Could one of the door module connectors cause all of these system failures? I just did a direct test of my battery and it is reading 12.25 volts.

 

Your battery needs to be at least 12.5V

 

Ok, Just recharged the battery. The machine at the auto parts store said it is a good battery. Hooked back up and cleared all the codes. Started the car and two codes came back right away and keep coming back each time i clear them.

HVAC
B0441HC
B0362HC

Also remembered that lately my driver's seat control has been acting up. If I try to slide it forward it only goes for a second then stops. I have to keep hitting the forward button to get it into position.

My question is, if it was the battery, then why would the car drive normally for several miles before all of the failures? I thought that if the battery was low the computer would not boot properly and give instant failure??

If the freshly charged battery does not do the trick. I'm thinking driver's door mod or seat mod?

 

You have more than one issue BUT,,,,,,, lets solve the one that shuts you down..

Examine the rubber accordion tubes that connect to the door and door pillar. Pop it out of its holes. Pull the door connectors out of the door A pillar.
Disconnect the power connector and carefully examine the female pins. You will find some of them spread apart.

When the damaged femal pins make poor contact it causes the DCM to turn on and off and make noise on the serial data line.. Thats most likely where all the U series DTCs came from.

Rebend the female pins so they make better contact with the male pins. I use a dental pick . Clear the DTCs and remonitor..

Once thats fixed, we can work on the HVAC acuator issues causing the other two codes.

BC

 

Thanks Bill. That was going to be my next move. I just drove the car for about an hour with no problems, but I'm not holding my breath. I have to drive from Florida to Tennessee in a couple of weeks for corvette expo. I don't want to have problems. The hvac is the least of my concerns at the moment. I'll check the door connectors tomorrow. Is the seat module connector easy to get to? Might as well check that one too.

 

May have to remove the drivers seat to get a good look at it but, Ive disconnected mine from under the seat.

BC

 

Well I haven't hade the issue reoccur after cleaning grounds and messing with the battery, but I still wanted to check and grease both door module connections. I pulled the boot off of the driver's side and tried to pull the wires out of the door, but they dont come out. Is the connector on the door side or the car side?

 

do not grease electrial connections!!!

 

dielectric grease????

 

ABSOLUTY!! You can apply it to the rubber seals but, I would NEVER put it inside the male /female pins!!

If you are worried about moisture, find some marine compound designed for that specific purpose. I use CORROSION X.

Bill

 

Thanks!

I always thought this type of grease conducted electricity and that is why is was used on connections. Glad you guys taught me otherwise.

 

IF,,,,, it conducted electricity,,, the entire connector would be a short circuit. When you SLATHER it in the connector, its NOT selective where it goes.
IF,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, the male and female pins have a proper positive pressure contact, it will displace the grease and make contact.

IF,,,,,,,,,,,,,,,, for some reason there is insufficient proper contact, it will cause intermittant or no contact.

Extract from internet article: ( http://ftp.pwp.att.net/w/a/wayneorwi...ric_grease.htm )

Using Dielectric Grease on connectors.

A lot of people use dielectric grease on connectors. Some people mistakenly believe that dielectric grease is a conductor. In fact, it is just the opposite. It is an insulator, and a good one. That is the basic definition of dielectric, an insulator. Dielectric grease is typically made of silicone grease.

As an insulator, dielectric grease is good for use on spark plug boots. This was one of the original applications on vehicles when the high energy ignition systems came out. It can help insulate the connector, and in particular on a motorcycle where it can get wet, it waterproofs the spark plug boot. And because it is silicone, it is fairly stable at high temperatures and won’t affect the rubber and plastics.

So why would you put an insulator on a connector? The idea is that you use a thin layer. When you push the connector together, the grease is pushed out of the way enough to get a connection, and the surrounding grease then keeps out water and oxygen. The connector will be protected from the environment, and less likely to corrode. Plus the silicone is safe for the plastics and PVC insulation.

That sounds good, so far.

So why not smear it on everything? Well, there are a number of reasons.

1) Silicone grease outgases constantly. If the silicone gas gets near a connector or a contact such as a relay, and there is any arcing, the spark at the contact can create silicon dioxide. Some companies even suggest that the silicone gas from dielectric grease can travel many feet through the insulation on a wire and damage a contact on the other end. Omron states that even their sealed switches can be damaged by nearby silicone grease out gassing. Reference below for more info.

2) It is an insulator. It can prevent contacts from touching. If you must use it, use a very thin layer.

3) If you have a corroded connection, silicone grease will not help. In fact, it can only make a connection worse. It can never improve anything. Dielectric grease will never make a poor connection better.

4) It attracts dust and dirt and it due to the out gassing, it hardens over time.

This means that if you smear a lot of silicone grease on connectors, you may see nearby relays, switches or points fail later on. And since the silicone grease does nothing at all to improve the connection, and in fact may insulate the contacts in the connector increasing the resistance, the connector may still fail.

So what do you do? Look for a contact enhancer/lube. While most contact cleaners are simple solvents that just wash the connector off. There are contact enhancers that deoxidize the contact surface and actually work to lower the contact resistance (make a better connection). Most contact enhancers leave a lubricant behind that protects the metal and continue to deoxidize the metal and improve the connection. They can work to lower the resistance and actually make a BETTER contact as time goes by. The best you can hope for from dielectric grease is that it seals it enough to not get much worse. I have used Caig Deoxit on my bikes for a few years now. I first found out about this on my job when I had to correct an issue in a scale load cell connector system that could not tolerate even 5 thousandths of an ohm of resistance drift. We had a connector in the field that had been improperly plated and was starting to drift, mostly in warm humid areas like Florida. Our testing showed that the Caig Deoxit could be a good long term fix. We ended up using the Deoxit to stabilize the bad units until we could get corrected wiring harnesses built with the correct connectors. We also put a layer of Deoxit on the new parts to protect and keep them clean over their lifetime. This totally solved the resistance drift issue that we had. Our information on this product showed that the contact would actually get better for a period of over 1 year. The resistance would then begin to deteriorate, but at a much slower rate that a connector without the Deoxit.

I still use a small amount of silicone grease on my spark plug caps. It helps to waterproof them and makes it easier to pull the cap off. (have you pulled a plug cap on a Stelvio yet?) But I use it in very small amounts and never near a relay or switch.

Useful links:

1) http://www.ia.omron.com/product/caut...rrect_use.html

2) http://machinedesign.com/article/lub...-switches-1025

3) http://www.echeloninc.com/contactlubrication.htm

Wayne Orwig

 

Drumbum:

Take a look at my thread:

http://forums.corvetteforum.com/c5-t...hink-long.html

Bill Curlee has been helping me troubleshoot.......your story sounds awfully familiar. I am slowly getting closer to an answer......but not yet. This gremlin is truly the Big Kahuna of Gremlins.