Car doing weird things -U1255 Serial Data Line Malfunction-
Thread Starter
Melting Slicks
Joined: Nov 2003
Posts: 2,898
Likes: 5
From: Plainfield, IL
Car doing weird things -U1255 Serial Data Line Malfunction-
Just last week my passenger side door completely stopped working. The window, lock/unlock, mirror, and switch itself. I come home look at some fuses and everything is fine. After a few minutes of messing around everything starts to work again. Just today I checked codes and had this: U1255 Serial Data Line Malfunction listed twice one had an H for history. When pulling my car in tonight I turned my headlights off but they stayed on. So I cycled them again and they went off as normal (I have HID's with a harness).
Only thing I have done recently was relocated an amplifier for my sub to a new position and changed a ground position which is actually attached to a factory ground with another wire. Also seemed to notice my door switch lights dim unusually more than normal if say I was putting a window up. Anyone have any idea what the heck is going on?
Is something wrong with my passenger side door module? could my battery be on its last legs (original 99)?
P.S. I have Window Valet installed if that makes a difference. I have heard of some guys cars doing weird things with it in.
Any ideas are appreciated,
James
Only thing I have done recently was relocated an amplifier for my sub to a new position and changed a ground position which is actually attached to a factory ground with another wire. Also seemed to notice my door switch lights dim unusually more than normal if say I was putting a window up. Anyone have any idea what the heck is going on?
Is something wrong with my passenger side door module? could my battery be on its last legs (original 99)?
P.S. I have Window Valet installed if that makes a difference. I have heard of some guys cars doing weird things with it in.
Any ideas are appreciated,
James
Last edited by JTS97Z28; Aug 20, 2005 at 09:44 PM.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
James!
This sounds a lot like my 98 MN6 coupe! The last year that I owned it, I was ready to burn the car and claim it on insurance!
After troubleshooting it for 6 months, it came down to a bunch of bad ground connections. Now she is as good as new!
Here is a link to my ground connection post. It has helped a lot of people:
http://forums.corvetteforum.com/show...ion&forum_id=1
My recommendation would be to remove your door panel and carefully examine each and every connector in the door. There have been quite a few cases where the door connectors have been loose and correded and even some where the wires have pulled out of the connector.
The ground for the door is under the plastic door sill cover. Remove the plastic cover (It just pulls straight up). Once it is off, follow the colored body panel forward until it starts to sweep up towards the door hinge. Right where it sweeps upward, you will find a small void where the ground connector lives. You will need to remove it, disassemble it and clean it.
Here is what the connector will look like once it is out.
Examine the post and it will explain all about cleaning the connectors and ground points.
How old is your battery and what kind is it?
Bill C
This sounds a lot like my 98 MN6 coupe! The last year that I owned it, I was ready to burn the car and claim it on insurance!
After troubleshooting it for 6 months, it came down to a bunch of bad ground connections. Now she is as good as new!
Here is a link to my ground connection post. It has helped a lot of people:
http://forums.corvetteforum.com/show...ion&forum_id=1
My recommendation would be to remove your door panel and carefully examine each and every connector in the door. There have been quite a few cases where the door connectors have been loose and correded and even some where the wires have pulled out of the connector.
The ground for the door is under the plastic door sill cover. Remove the plastic cover (It just pulls straight up). Once it is off, follow the colored body panel forward until it starts to sweep up towards the door hinge. Right where it sweeps upward, you will find a small void where the ground connector lives. You will need to remove it, disassemble it and clean it.
Here is what the connector will look like once it is out.
Examine the post and it will explain all about cleaning the connectors and ground points.
How old is your battery and what kind is it?
Bill C
Thread Starter
Melting Slicks
Joined: Nov 2003
Posts: 2,898
Likes: 5
From: Plainfield, IL
My battery is original AC Delco from 1999. Car has 32,000 miles now. Tomorrow I plan on taking a look at some of the grounds and more specifically the one I relocated when I added the ground wire for my sub amp. This is the one located just behind the passenger side door behind the plastic trim pieces.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
I seriously recommend getting rid of the AC Delco! I was in the same mind set as you! The battery is still good,,, yhy replace it? The delco battery's can and will leak acid from the terminal post areas and that will destroy your PCM, wiring harness and vacuum lines, Invest in a good battery. OPTIMA is what I got for my Z06 and it works very well.
Sounds like the stereo ground is causing you some problems. Just get a self tapping sheet metal screw and put the stereo ground on a frame component under the dash and return the chassis ground to the as installed condition.
BC
Sounds like the stereo ground is causing you some problems. Just get a self tapping sheet metal screw and put the stereo ground on a frame component under the dash and return the chassis ground to the as installed condition.
BC
