Adding Cruise Control to a MY98

[KC-Boxster]

Tim

I'm a bit confused. :huh: :huh: Firstly, my sheet 13 is a bit unclear, and I mistook the ground connection terminal to be F, and it is E. (It's clear on the Boxster diagram I have).

Even so, I have a nagging feeling that the earth connection is to the bottom-right pin in my photo (the one next to the small polarising rib). If you get a chance, could you confirm (or otherwise) that the brown wire goes to that pin?

What you are suggesting is a mirror-image of what I am now expecting - and you were looking in a mirror! :D :D

edit: I need to type faster - our messages crossed! - that's great - I think we are on the same page now!

Richard you are correct. I was looking at it backwards through the mirror. I have revised my previous reply and added a better picture. So see if the latest posting makes more sense.

Tim

[Richard Hamilton]

Tim

That's perfect - you are a star!

Could you share the number of the connector and pins you think might be right? I am hoping to get all the bits together during the next 3 or 4 days, and I'm keen to get started.

BTW, if you can put together a reasonably priced kit, they will sell like hot cakes. Do you want a UK distributor?? ;) ;)

[Paul Fraser]

You'll still need an accelerator unit won't you? i.e. the one in a non-cruise control car won't do?

[KC-Boxster]

You'll still need an accelerator unit won't you? i.e. the one in a non-cruise control car won't do?

You are correct. The basic pedal and inner workings are all the same. But the non-cruise control pedal is missing the third inner actuating cam that is hooked to the cruise control cable.

Tim

Tim

That's perfect - you are a star!

Could you share the number of the connector and pins you think might be right? I am hoping to get all the bits together during the next 3 or 4 days, and I'm keen to get started.

BTW, if you can put together a reasonably priced kit, they will sell like hot cakes. Do you want a UK distributor?? ;) ;)

I would if I had it but all I could find was a place that has a plug and pigtail assembly that appears to be correct. I will have to wait till I get it to see if there are any Part Numbers on it that will lead us in the right direction.

Tim

[Paul Fraser]

Thanks for that: I actually asked the OPC for prices for the parts at one point because it was so hard to find a 97 Boxster unit and accelerator for LHD here in the UK (btw looking at the PET there seems to be a different CC unit for the 97 cars and another for the 98-on. There is also a different accelerator pedal for the 97 and 98-on cars. I wonder if it is just a matter of using a 97 cc unit and accelerator or a 98 unit and accelerator together?).

If I have the correct piece of paper the prices are:

£167.31 for the accelerator pedal

£337.91 for the cc unit

£8.35 for ? (clutch or brake switch probably)

I suspect if you can source the cc unit outwith Porsche it will require a 98-on accelerator pedal for 97MY upgrades...

[KC-Boxster]

Thanks for that: I actually asked the OPC for prices for the parts at one point because it was so hard to find a 97 Boxster unit and accelerator for LHD here in the UK (btw looking at the PET there seems to be a different CC unit for the 97 cars and another for the 98-on. There is also a different accelerator pedal for the 97 and 98-on cars. I wonder if it is just a matter of using a 97 cc unit and accelerator or a 98 unit and accelerator together?).

If I have the correct piece of paper the prices are:

£167.31 for the accelerator pedal

£337.91 for the cc unit

£8.35 for ? (clutch or brake switch probably)

I suspect if you can source the cc unit outwith Porsche it will require a 98-on accelerator pedal for 97MY upgrades...

I have both the 97 Cruise/Pedal assembly and the 98/99 Cruise/Pedal assembly and they appear identical. I actually have the 97 version in my 99 and it works perfectly so I am guessing the only real difference is either minor programming or circuit board changes in the Cruise Control Module itself. They both use the same electrical wiring and hook up identically.

Purchasing all of the required parts new from Porsche is either cost prohibitive or impossible since they don't offer all the required pieces.

I have actually found sources for all of the required components in the aftermarket to create a kit with the exception of just a couple of wire terminal ends (Which I will locate) and the cruise control cam that would be required to be inserted into the factory non-cruise accelerator pedal. This leaves us with the following options:

Option 1: Individual car owners could source the Cruise Control/Pedal assembly and the 3 or 4 Stalk Steering Column Switch assembly from a salvage yard or the dealer (if you have deep enough pockets) and I could build up a Wire Harness to facilitate the installation.

Option2: I could provide a kit which would include an aftermarket Cruise Control Module (Which is virtually identical to the factory Porsche VDO unit), Wire Harness and aftermarket Cruise Control Switches that mount to either side of the airbag. This option would require me to go into production and have an injection molded Cruise Control Cam made to work with the factory non-cruise control accelerator pedal. This is all very doable and I would suspect the final cost would be around $400 to $500 dollars. Before I would venture off into this project I would need a significant number of potential interested car owners.

Options3: We could come up with some sort of variation of Option1 and Option 2 above so those wanting the stock Steering Column Switch could use it instead of the aftermarket one on either side of the airbag.

I have already written the first draft of the Installation Guide and it is currently being reviewed by another dedicated Porsche owner. Once complete I will post it so everyone can see what's required.

So the bottom line to all interested Porsche Owners is to let me know how important of a project this is to everyone so I can make a decision.

Regards,

Tim Casey

Edited July 25, 2006 by KC-Boxster

[Paul Fraser]

Hi Tim: I plan to upgrade my LHD 97 Boxster and RHD 98 996 so there are two votes already. Obviously I need to read the DIY but I think I would prefer the ability to purchase the individual parts. In order of interest these are:

1. Harness (think you are onto a winner here. Saves time and probably near impossible to source from a breaker unless you do what you did).

2. Aftermarket CC unit (although this depends on cost -- the second hand prices I've been quoted over here vary from $100 to $225 exc tax delivery).

3. The cam (again, depends on cost, quoted second hand prices of pedals $100 exc tax/delivery).

4. Aftermarket cc switches: would prefer to keep it stock.

A couple of supplementary questions if I may:

When you say the aftermarket cc unit is 'virtually' identical is the only difference cosmetic or is there something else?

Can I rob a 98 cruise pedal of its cam and convert my non-cruise 97 pedal to a cruise one?

Keep up the good work!

[KC-Boxster]

Hi Tim: I plan to upgrade my LHD 97 Boxster and RHD 98 996 so there are two votes already. Obviously I need to read the DIY but I think I would prefer the ability to purchase the individual parts. In order of interest these are:

1. Harness (think you are onto a winner here. Saves time and probably near impossible to source from a breaker unless you do what you did).

2. Aftermarket CC unit (although this depends on cost -- the second hand prices I've been quoted over here vary from $100 to $225 exc tax delivery).

3. The cam (again, depends on cost, quoted second hand prices of pedals $100 exc tax/delivery).

4. Aftermarket cc switches: would prefer to keep it stock.

A couple of supplementary questions if I may:

When you say the aftermarket cc unit is 'virtually' identical is the only difference cosmetic or is there something else?

Can I rob a 98 cruise pedal of its cam and convert my non-cruise 97 pedal to a cruise one?

Keep up the good work!

The aftermarket unit appears to be a direct derivative of the original VDO unit but has a generic mounting pad so it could be mounted just about anywhere. One suggestion would be out in front next to the battery where there is ample space and easy access. The internal Printed Circuit Board has also been redesigned by the current manufacturer so that it can be programmed via a DIP switch for virtually any vehicles speed input signals. This unit appears to be top quality and is reportedly the standard aftermarket Cruise Control Installation Kit for Ford and Chrysler dealers.

You can take the cam out of a 98 Pedal but if you already have a 98 pedal then you should probably use the entire pedal because it will have the cruise control cable already attached.

It will probably be a week before I get the DIY instructions revised and posted.

Tim

[Richard Hamilton]

Well, thanks to Tim the cruise retrofit in my '98 996 is complete, with a lot of help from my friends at wrightune.co.uk. It works brilliantly, and I'm delighted with the outcome, but it wasn't without its problems.

Mechanically, everything was straightforward, but I didn't have the benefit of an original wiring loom, which is what caused the hassle. Therefore, I would not recommend tackling this project without a properly constructed wiring harness.

[Paul Fraser]

Was the hassle in getting the appropriate wires and connectors...?

[Richard Hamilton]

Was the hassle in getting the appropriate wires and connectors...?

Absolutely! I had terminals that I thought were right, but Mr Porsche made sure everything wasn't quite standard. We ended up tweaking every connector to make it fit. It ended up as a safe and secure installation, but I wouldn't recommend doing it this way. If Tim can make a wiring harness (and I know he has sourced most of the components) then it would make the project do-able. Without the harness it's a nightmare.

[DG Boxster]

I am gathering parts to add OEM cruise control to my MY98 Boxster.  I found this old post which is helpful.  The OP described writing a DIY guide but it doesn't look like it was ever completed?  If anyone can add anything to help I'd appreciate it!

[Richard Hamilton]

I've attached a copy of Tim's guide.  By the way, I bought ten of the 10-pin plugs which go into the cruise actuator, and I think I have 2 or 3 left.  If you want one, drop me an PM with your address and I'll post you one.

 

Factory Cruise Control Retrofit for 1997-1999 complete - 3.pdf

Edited September 1, 2018 by Richard Hamilton
Corrected Bridge Plug Number

[DG Boxster]

THANKS!  What a great document.  Someone should post it in the DIY section.  YAY I'm gonna have Cruise Control :)

[Erv Plecter]

First off, my apologies for necroposting this thread, I just wanted to thank Richard Hamilton for his very valuable help on the retrofit and for providing me the hard to find connector for the servo / actuator unit.

The provided PDF document was spot on and I got my cruise control working first place (for those wondering, as it's a separate device from the ECU, it didn't need any activation of some sort, flick the stalk switch and get the instrument cluster green cruise control light).

 

A couple of remarks :

- the PDF has a small mistake regarding the wiring : Pin C of the cruise control actuator (BK/OR) goes to bridge plug 6/2 (not 5/2). 6/2 indeed bridges the stop light switch (close contact). I don't know why the actuator needs both NO and NC contacts but BS 6/2 bring the NO one.

 

- The real time saver here is to purchase a CC servo plus gas pedal assembly. I got one on ebay for about $160. I asked Richard to confirm before purchasing, but indeed, the regular gas pedal DOES NOT have the middle cam that overrides the manual gas cable. I kept my car pedal installed in place to NOT have to swap it for the new one and saved the disassembly of the main gas cable and cam. I simply scavenged the CC cam from the ebay pedal and installed it in the stock pedal. It was tedious to get there based on the little slack there is (as the tutorial states, 13mm) but I got that done in 2 rounds of 1hr work.

 

- My car is LHD, there are indeed slotted drills in the brake pedal support, it's just freakin' hard to get a pipe wrench in there. It took ages to both see what I was doing and slowly tighten the 3 screws, sometimes 1/20th turn by 1/20, especially the one that is nearest to the dash / up. But I eventually got there :-)

 

- Get some proper fabric tape to make your loom / wire harness. Tesa makes a wonderful one. Never use PVC / electrical tape, that's one of the biggest insult to your car.

 

- My car is manual and doesn't have the kick-down switch. In place, there's a filler part that is sandwiched between the 2 halves of the gas pedal and it's a PITA to keep in place when trying to re assemble it after adding the middle cam. Use a dab of hot glue to attach it to one half, that will easy your re assembly job

 

- finally, my CC unit was NOT provided with all the mounting screws. Researching they are PT10 Ejot screws, self taping for thermo plastic but I couldn't source them easily. In replacement, your can install a blind rivet / stud in the mounting feet of the CC servo, I used Rivkle ones, M5. Drill, a dab of loctite 406 and then use the plier to lock it. As it's not as self locking as the EJOT screws, mount the screws with a dab of blue thread lock (light) just to ensure the servo won't move with the vibration. It should move from the CC operation as it's pulling against the slotted holes and tends to remain in place while servoing.

 

 

Getting the cruise control was worth the effort. First, just for when I sell the car (if I have to, clearly keeping it for now). It's like A/C, people are now used to it and want all the options in the car. Also, based on the fact that car really wants to go fast, it's hard to drive it on the highway at just 130 Km/h without spending your energy and focus just on the speed. The cruise control is really pleasant to have just for this.