'03 Central Locking Stopped Working

2003 3500 with Central Locking System. No alarm.

The Central Locking System stopped working. With the key fob (new fob battery), nothing. With the console button, nothing. I have to lock and unlock each lock manually. When I use the key fob I sometimes hear a faint click, but nothing more.

The #5 25A fuse is fine. All other electrical systems are fine. Glow plug and starting are fine.

I cleaned the sliding door and rear door contacts.

It acts as though there is corrosion on a grounding lug. Just not getting voltage at whatever current draw it takes.

Somebody mentioned that a dying main battery can do this. Doesn't make sense if it still glow plugs and starts normally.

Advice?

Thx,

Rick M

Did you recently hit something?

The Sprinter's air bag system notices significant impacts (such as hitting a loading dock or a parking lot bollard) as "ekk! Crash pending!" and kills the auto-lock system.
Until the ABS is reset (with a DAD or similar device), the remote system won't lock stuff.

But i *think* it still accepts "unlock" commands, so that votes against that cause.

Other things that can go wrong (i.e. forum members have seen them): where the wires from the front door enter the A-pillar, they're close enough to the door travel limit mechanism that it can occasionally chew the wires... which would have a definite impact upon their operation.

Do the *lights* on the front panel switch operate properly (blinking if a door's unlocked/ajar, etc)?

The door lock circuits are shown in section 8W-61 of the service manual, available at http://aie-services-2.net/Sprinter/

--dick

I've had non functioning central locking for years now. I have also never found out why. Like dick says, the fob and dash switch will UNLOCK, but they don't LOCK. But the fob doesn't UNLOCK normally; I have to press it multiple times, and it does the side/back doors first, and then the driver door. It didn't fail all at once, it would just sometimes not work, and it got worse over several months until it stopped. I remember it locked all doors BUT the driver door once, because I was surprised to find it unlocked returning to the van.

I found the cut and messed up wires in my driver door, and fixed them. Still no central locking. I use a key to lock/unlock my doors like in the olden days.

No, have not hit anything. I don't think the airbag system has been affected in any way.

The lights on the console locking switch seem to act normally. They do flash for doors ajar, but they also flash with the ignition off. Also, just now, for example, while driving with all doors closed, and only the driver door unlocked, the DOWN light was glowing constantly.

You mention ABS reset. I wonder about that one. I had an ABS rear right sensor go out and get repaired a few months ago. While it was out the brakes would chatter just before the full stop. Right now, however, the brakes are acting normally.

I have an oil and filter and fuel filter change coming up. I will have them check all this.

This is really weird.

Thx

By "ABS" i meant "air bag system" (my apologies for Dodge/Freightliner/MB having confusing TLAs (3-letter acronyms).)

The tally lights on the dash switch do operate with the key out and everything shut down... they turn off a minute or so later
(the same is true for the dashboard's mileage display)

--dick

I had this problem the other day, for awhile until I realized that I was hitting the key release button and not the lock buttons.