Door Lock Module Repair
Thread Starter
Burning Brakes
Joined: Nov 2002
Posts: 807
Likes: 21
From: Los Altos CA
Door Lock Module Repair
A few years ago, I repaired the door lock module on the driver's side of my C5 following instructions given in this forum and it worked well after that (50 K miles ago). When the passenger side stopped working, I figured it was the same thing and did the same repair. This consists of replacing the "lock" relay. However, after replacing the passenger relay, the door lock was unreliable although it went from never operating to operating some of the time.
I then decided to also replace the "unlock" relay and the system now works all the time.
In the picture, the lock relay is at the lower left and the unlock relay is right above it. Shown are the new relays so your module will show different writing on the relays. De-soldering is difficult and I did some research on the web but still found it to be difficult. If you have an electronicy friend or a convenient professional, I would suggest that you take advantage of one of them. It will still be cheaper than spending $500 for a new module.
I then decided to also replace the "unlock" relay and the system now works all the time.
In the picture, the lock relay is at the lower left and the unlock relay is right above it. Shown are the new relays so your module will show different writing on the relays. De-soldering is difficult and I did some research on the web but still found it to be difficult. If you have an electronicy friend or a convenient professional, I would suggest that you take advantage of one of them. It will still be cheaper than spending $500 for a new module.
Last edited by white90conv; Jul 29, 2014 at 11:36 PM. Reason: spelling error
Drifting
Joined: Dec 2003
Posts: 1,895
Likes: 84
From: Darien IL
I tried with de-soldering wicking and could not get it apart. I was using a 75 watt pencil type soldering iron. I took it to work and our tech had all three off in a few seconds. His solder iron was rated up to 400 watts.
Le Mans Master
Joined: Mar 2011
Posts: 6,835
Likes: 302
From: Columbia SC
The 3 on the left are all the same. The top one is for the mirror heating element.
The different one on the right is for the window. It is different because it has 2 coils and 2 sets of relays.
Not at home but if anyone wants to know the part numbers I can post later. They are inexpensive and very available but from 2 different sources.
Also, these relays are the same for both door modules but each circuit board is different since the LDCM has Memory interface.
The different one on the right is for the window. It is different because it has 2 coils and 2 sets of relays.
Not at home but if anyone wants to know the part numbers I can post later. They are inexpensive and very available but from 2 different sources.
Also, these relays are the same for both door modules but each circuit board is different since the LDCM has Memory interface.
Instructor
Joined: Jan 2012
Posts: 155
Likes: 0
From: Frisco Texas
Mouser.com is where I go. Here is the lock/unlock relay. http://www.mouser.com/ProductDetail/...6a9wAx7681Vg==
