For the past two weeks I have noticed that my right hand outside mirror on my 2001 C5 will not hold its correct position upon starting the car. I have tried reprogramming both M1 & M2 (to the same settings) after adjusting the mirrors and telescopic wheel. The left mirror and telescopic wheel always move to the correct memorized position as expected, but the right mirror has a mind of its own moving to a non-programmed position. If I then quickly touch the M1 button the left mirror and telescopic wheel stay fixed, but the right mirror moves further off axis. Each time I press the M1 button the right mirror moves further off target. Also some time the M1 light flashes when this occurs which I guess indicates a fault? Any ideas?

 

I guess due to the lack of response on this topic that I must not have a simple solution at hand? Guess it is time to head to the Dealership?

 

I had the same problem on my Z06 mine was the right mirror also, I replaced passenger door control module and it solved my problem.

Steve

 

I ran diagnostics, and the only code I get displays the RFA - Code U1064 H? The description indicates loss of communication with BCM. Is this something I can fix - like a loose connection?

 

Anyone with any info on this?

 

The U codes are common and not usually a concern, especially since your is a History code. But your mirror is acting haywire in conjunction with a code, I would check and clean all your grounds. See sticky “IMPORTANT ELECTRICAL INFORMATION (Long!)” by Bill Curlee at the top of the Tech section, an EXCELLENT post and should get you on the way…

Here’s the scoop on U1064;

The serial data circuit is used to communicate information between each system connected to the serial data line. Each system is assigned a specific recognition code (source ID). This code is used to identify which system is communicating on the serial data line. Systems communicate with others by periodically sending messages on the serial data line. These messages contain specific information (or commands) a system requires to function properly. When a system receives a message it also learns the source ID of the system that sent it. This source ID is used to determine which system actually sent the message and for State of Health (SOH) monitoring. SOH monitoring determines if a system is unable to communicate properly. Systems periodically send a SOH message to each other containing their source ID. If a system fails to receive a SOH message back from a system that it communicates with, then a DTC identifying what system did not respond will set.

Diagnostics
· If the problem is an intermittent loss of communications. Carefully inspect the serial data line and related components for the following intermittent conditions:
o There is an intermittent open or short (to ground or voltage) in the serial data line.
o Intermittent loss of communication with the BCM.
o Damaged or loose star connector terminals.
o Poor connections/terminal tension at a harness connector.
o Intermittent BCM communication due to a loss of power or ground to the BCM.
· Communication DTCs do not necessarily indicate a malfunction. These DTCs are only intended to aid in diagnosing an intermittent communication malfunction that is accompanied by a symptom. If the vehicle does not experience a symptom related to a communication malfunction, these DTCs can be disregarded.
· If the serial data line is shorted to ground or shorted to voltage, all systems connected to the same serial data line will not be able to communicate properly. Systems capable of storing loss of communication DTCs (DTCs with the letter U as a prefix) will have these codes stored in their memory. If a DTC U1064 is stored in a system's memory, check for the same DTC stored in other systems capable of setting a DTC U1064. The IPC, RFA, LDCM and RDCM all monitor the SOH message from the BCM. If other systems have a DTC U1064 stored, check the BCM for an intermittent malfunction. If other systems do not have a DTC U1064 stored, check for an intermittent malfunction in the system that set a DTC U1064. After repairing a DTC U1064, clear all DTCs from all systems capable of storing communication DTCs.
· If the DTC is a history DTC, the problem may be intermittent. Perform the tests shown while moving related wiring and connectors. This can often cause the malfunction to occur.

 

Another thing is to make sure you're using the right key fob. I was using fob #2 for about a week (when I first bought the car) and nothing with the memory system was working correctly. I did some research, changed to fob #1, and magically everything fell into place.

 

Also some time the M1 light flashes when this occurs which I guess indicates a fault? Any ideas?


The light flashes when you hold the button down too long and it resets the memory to the current settings, not when there's a fault. Don't think the settings are your problem if the mirror moves every time you press M1. It should only move the first time you press and not at all if you have used the correct fob to tell it which settings to go to when you enter the car. Sounds like you have an issue with the control module or connections to me. Good luck, post what you find.

 

Mine does the same thing every once in a while. As if it loses its memory and is always pointing down too far. Once a week it will be off and I have to reteach the position.

 

happens all the time to my Buick rendezvous, also the passenger mirror, haven't noticed the problem n any of the vetts, but guess GM has the same memory/ computer fr both cars

 

I went by the dealership a couple days after my original post here and the Service Manager said he had never heard of that behavior. Therefore, I decided to wait to take any action since it was just a nuisance.

This problem was persistent for about a month 100% of the time and finally would include right mirror and/or left mirror and eventually the telescopic wheel setting. One day about two weeks ago it just stopped and everything has been working ever since (so far). So something isn't right. I had also previously tried disconnecting the battery overnight just to clear everything, but that had no effect.

 

Again, Take a look at your grounding points and clean them real good.

 

Not sure if its related, but besides my mirror doing that, my seat is sometimes a little higher than normal. I checked for codes and got a vertical seat sensor something. But nothing for the mirror.

 

Good tip - I will check those out.