Mercedes Cruise Control Diagnostic Tool
 

As much as I hate the thought of going to the dealership (even though our local one is a good one as dealers go)....

I am wondering whether it would be worth an hour of labor to have them use their fancy machine to diagnose my cruise problems. Has anyone ever done this? If so, how comprehensive are the results? While part of me wants to resolder the amp and see what happens, there's another part that things I should get a dealer diagnosis on this. From everything I've read, it take their proprietary tool to find out everything that's going on with the cruise system.

Thoughts?

I'd suspect the dealership is about $110-125 an hour, so you might check out this gentleman before you go that route. Looks like you can pull your parts and he'll test them, if you go with a rebuild the testing cost is waived. You can ship the parts USPS Priority Flat Rate Box for about $11.
http://gdl-online.com/process.html

"If we ultimately rebuild a unit there is no charge to check it out and notify you via email. If we bench test only the charge is only $45 for each unit or $60 if we test Amplifier and Actuator at the same time. We offer a much more conclusive test and adjustment of the Actuator. The only other charge is return shipping."

I've used his ACC rebuilds in a couple of my cars and installed a CC Amp in someone elses 87 300D a couple years ago that's been working fine ever since.

I'm familiar with and have used GDL. The problem is that a bad amp can be caused by a bad actuator. So, in order not to throw good money after bad, I'm thinking it might be good to have an authoritative diagnosis.

That's why I posted GDL, he will test both the amp and the actuator for $60!

That's true....I guess it's a question of my being able to remove and reinstall both by myself. Otherwise, I end up spending more than I'd pay the dealer to diagnose.

I'm pretty sure a worst-case bad actuator is just a short circuit of some kind. Should be doable with a multimeter, just need to know which pins/sets of pins to test. Then again, the motor is isolated by a relay until you power it, that might make it hard to test for a shorted motor.

Getting above my pay grade. Some times I'm resigned to live without cruise, other times I want to puruse a cost-effective fix. But if I have to replace both amp and actuator....hard to justify the expense.

I changed mine out. The whole thing. Went with an aftermarket set. Link is here: http://www.peachparts.com/shopforum/diesel-discussion/219993-official-audiovox-ccs-100-install-thread.html?highlight=ccs-100

My install went pretty easy and the VSS (vehicle speed sensor is usable.) I even used the stock cruise control stalk.

Looks like you've got my exact car. So, if I went the Audiovox route, I would go with the vacuum unit rather than this electronic unit?

http://www.amazon.com/Audiovox-Ultracruise-250-1316-Electronic-Control/dp/B001UT0CXA

I am using the audiovox cruise system attached to the stock control stalk. Works absolutely perfectly. Just as good if not better than the original system.

Sounds intriguing. Which one would I get for a 91 300D?

What kind of labor would it take to install the Audiovox unit....if I have my tech do it?

Also, is the vacuum controlled unit, the CCS-100, even available anymore? Has the electronic unit replaced it?

Looks like a easy DIY if you read through the Audiovox thread posted above.

here are a couple e-bay listings
http://cgi.ebay.com/ebaymotors/AUDIOVOX-CCS100-CCS-100-CRUISE-CONTROL-KIT-PLUS-EXT-KIT-_W0QQcmdZViewItemQQitemZ110577033905QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories


http://cgi.ebay.com/ebaymotors/AUDIOVOX-CCS-100-UNIVERSAL-CRUISE-CONTROL-KIT-NEW-_W0QQcmdZViewItemQQitemZ320579763118QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

Charlie

You could go with either the vac or electronic control version. I went with the Vac cause that's what they listed in the thread. If you have any question after reading through the tread let me know. It didn't take very long. I pick up an dead amp (under the dash) so I could use the connector for to tie everything into.

I have it wired so OFF = OFF
UP = Accel/Resume
Down = Set/Decel
Towards You(Resume) = Tap of the brake (disengage)