How to fix lock/unlock system?

99sport

Well-known member
svaric, are you saying the front doors will power unlock after pressing the lock button on the center console, or after manually pushing in the interior door handle?

The Sprinter's lock controls have this weird programming where if a lock command is issued by any means (center console button, key fob, or manual locking), it will check the status of each door lock, and if one of the doors remains unlocked, it will power unlock all doors. If you immediately re-lock manually, it will lock, unlock, and lock again. This can be triggered by one of the locks physically not moving into locked position, or the circuitry that senses the lock state isn't completing the circuit. It's commonly caused by weak contacts in the rear doors or sliding door. Note that these contacts are not the same switch that activates the dome lights.

If you're physically pushing one of the front door interior handles into the locked position to activate the power locks, and the power locks then immediately unlock all doors, my guess would be that the problem is in the sliding or rear doors, not the front doors.
My passenger front door would do exactly what you describe, and I assumed it was one of the back doors, for the same reasons you list (higher likely hood of bad connections in back). After more trouble shooting I decided it was the front lock actuator and ordered a replacement. Before installing the replacement I cleaned the gunked up latch. At that point I decided to see what would happen with my old lock actuator and it worked!

So even though the back is a more likely candidate, it could still be a problem with the front.
 

svaric2

Member
Yes. Cleaning and lubricating the passenger door latch / mechanism (after removing it from the door) allowed the handle to stay locked without jumping back out.
I will try this and post back with results. Carb cleaner and white lithium grease should work I figure.
 

svaric2

Member
99sport, Thank you!

After cleaning locking mechanisms with carb cleaner (careful to not get it in electrical components) and spraying generously with white lithium grease, and then cleaning the dusty/grimy trim handle panel and lubing with WD40, the inner door handles on both doors push in and out automatically freely without jerking back out. I also sanded all the way to the copper on all contacts and pins for the sliding and rear doors so I know there is clean contact.

Now my door behaves like this:

Pressing lock on the aftermarket fob ALWAYS arms the system (to sound alarm if door opens/gets hit etc)
Pressing unlock on the aftermarket fob ALWAYS disarms the system

If I manually push in one of the levers on any of the doors and then press lock/unlock on the aftermarket fob, all locks will orient to the same position (so some mechanisms will remain in their current state) and a second press will toggle LOCK/UNLOCK on all the door mechanisms.

So I'm back at my initial problem. Although the doors are consistent with eachother, the aftermarket fob just toggles their position, so I don't know 100% what pressing a button on the aftermarket fob did. Atleast the system is armed and if someone does open the door the alarm and my fob will make noise.

Is there a chance he is wired into the center console and not the CTM? Does anyone with experience installing these know where connections need to be made?
 

svaric2

Member
Almost certainly the installer did not connect to the central timer module. There is no wire at the CTM that does what you want. The simplest fix is to solder to the two locations on the CTM board as described in this post. I did this a couple weeks ago and it does what you want.

https://sprinter-source.com/forum/showpost.php?p=189889&postcount=9
I will have to try this myself as my installer doesn't want to touch it. Are these instructions meant to work with any aftermarket system? I've got the Viper as mentioned in the first post.

Also, just to be certain, does your vans remote lock function like a normal car's does now? i.e pressing lock 3 times wont just toggle the locks 3 times, it should lock on the first press and remain locked for all subsequent presses? (and conversely the same correct behavior for unlock)?
 

Nautamaran

2004 140” HRC 2500 (Crewed)
Yes. The Viper has “lock” and “unlock” outputs, but the ctm’s internal board (or its wiring harness) is the only place these signals can tie into to properly trigger the door actuators... tying the Viper outputs into the dash switch (which is what toggles the door locks) is the wrong way to go, and produces the “toggle when I press lock” behaviour.

The thread 99sport linked above describes this in detail.

-dave
 
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99sport

Well-known member
I will have to try this myself as my installer doesn't want to touch it. Are these instructions meant to work with any aftermarket system? I've got the Viper as mentioned in the first post.

Also, just to be certain, does your vans remote lock function like a normal car's does now? i.e pressing lock 3 times wont just toggle the locks 3 times, it should lock on the first press and remain locked for all subsequent presses? (and conversely the same correct behavior for unlock)?
The CTM mod needs the alarm to provide a ground signal (instead of positive 12 volts). The viper alarm does provide a ground signal when the alarm toggles - so yes the alarm will interface with the CTM mod - just be sure you connect the added CTM wires to the correct output from the viper alarm - it has a lot of pin outs - read the viper wiring diagram.
 

svaric2

Member
A couple minutes of googling and I found the installation manual for the Viper 5806. It turns out I didn't need it. I first checked the toggle lock switch in the center dash to see if my installer initially hooked up the lock/unlock wires there and he did; they were both tied to the yellow/white dash wire. Undid those, fished the 2 wires back out and under the floor mat, through the seat, and followed the instructions in the writeup linked by 99sport and it works! Huge grin of satisfaction when I was testing it out. Lock and unlock do what they should do as on any other car. Thanks to everyone for input!

Now I've got a key and a seperate viper fob. Wondering if I can join these into a single switchblade type key. Don't know if its possible, since the viper fob has a battery indicator and remote start button. If anyone has tried I'd love to see what they did
 
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bcman

Active member
I doubt that's possible without some serious fabrication, maybe 3D printing a case that combines the top shell of the Viper fob with the spring, release button, and blade of your factory key (as well as the RFID chip). You'd probably have to go through several iterations to get everything working correctly, but that would be really slick.

The easier option is to downsize your key, if you're not using the factory fob functions. There are simple keys available with a slot in the plastic handle for the RFID chip. I was down to one factory fob/key, so I gutted it for the RFID chip and zip tied it to the ignition bezel, like MillionMileSprinter suggests. I then got a couple of "dumb" keys cut at Home Depot. They needed some modification to fit in the locks, but they're super slim and fold up nicely with the Viper fobs.
 

svaric2

Member
Yeah that would take a fair amount of work to get it all . I'm not using the factory fob, just a cut key from the installer and the viper fob. They fold nicely together as it is, but I'm obsessed with the flip key idea and would really like it if I could get it to work. I was thinking of sacrificing a spare factory fob I don't use and cutting a hole the shape of the viper buttons. I would be able to reuse the factory housing and blade, and move the viper antenna to the other side, but the viper PCB upper left corner gets in the way of the spring mechanism. I think I'll just live with it for now.
 
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