Subaru Cruise Control
With any of the cable throttle Subaru engines, despite sharing the vehicle speed signal and a few other connections with it, cruise control (when fitted) was not part of the engine management, but a stand-alone system. Subaru used four different cruise control systems on the EJ and EZ series cable throttle engines, any of which can be used in VW conversions, although some are easier to use in VW’s than others.
If your donor Subaru didn’t have cruise control, but you want it in your VW conversion we usually have the wiring in stock, and maybe some of the hardware. You’ll have to source the other hardware (we rarely have all of the hardware available).
If we’re doing the wiring harness work for your VW conversion, we need to know up front if you want to use the Subaru cruise control, for two reasons. Firstly, so that the cruise control wiring can be salvaged (to extract the engine management wiring from the Subaru harnesses, all non engine management circuits including cruise control (if not required) get cut away). Secondly, we build the cruise control wiring into a separate harness which plugs into the engine management wiring to get the power and other signals required, and we only add the necessary connector to the engine management wiring when the customer is using Subaru cruise control, or wants to in the future.
Subaru cruise control controls in a VW
All of the cable throttle Subaru cruise control systems had two controls for the driver. An on / off switch in the dash which also has the ‘cruise control on’ light built in, and a stalk in the steering wheel which provides all of the other controls (RES / CANCEL / SET or ACC RES / CANCEL / SET COAST depending on which system is used – the earliest system doesn’t have the speed increment decrement feature).
Without a squib / ‘clock spring’ to connect multiple wires to the steering wheel like modern cars have, fitting the stalk to the VW steering wheel is not an option, so it cannot be quite as ‘at your fingertips’ as it was in the Subaru steering wheel (at least not while still looking neat). There is only really one location where the Subaru stalk can be fitted in the VW. However, there are quite a few options when it comes to which Subaru controls to use, and how to fit them into a T25/T3/Vanagon.
Subaru Cruise Control controls in a VW – the neatest option
This is the neatest option as it combines the stalk, on / off switch and on LED into a modified stalk from a later Subaru model – no other visible cruise control parts are needed. It’s quite a bit more expensive than the other options as the later stalks are not cheap, and then require extensive modification (note the LED is not shown here):
Subaru Cruise Control controls in a VW – the cheapest option
The simplest / cheapest option is to use the Subaru controls from the Subaru which donated all of the other cruise control components – i.e. the separate on / off switch and stalk. This option comes with all mounting parts required, and the only VW modification needed is also to cut a hole in the upper steering column shroud to the template provided. However, a vacant VW switch location for the on / off switch is also needed
The instrument cluster location requires no parts or modification to VW parts. It does require filing about 0.25mm from the springy locking tab on the switch.
Both locations fit with the type of Subaru Cruise control on / off switch shown here (the most common one), but Subaru used numerous other switch designs in other models, many of which are less suitable (they had very different shaped buttons)
Unfortunately the ‘Cruise’ text on the switch ends up vertical in both locations, and can’t be rotated. That’s a small price to pay for the switch fitting with no modifications to the VW parts though. This simple / cheap method is perfectly functional, but our combined stalk / on / off switch / LED is much neater.
Our Subaru cruise control wiring harness work for the VW T25/T3/Vanagon also includes most of the other mechanical parts needed to complete the installation:
- Pedal switch brackets to suit whichever combination of pedal switches you are using
- Pedal switches if you don’t have them or only have one but need two (as with an auto Subaru donor going into a manual VW), at extra cost
- T25/T3/Vanagon cruise control stalk bracket and screws
- T25/T3/Vanagon upper steering column cutout template
- On / off switch adaptor for the column shroud location (i.e. in the VW heated seat switch location) if required, at a small extra cost
- Actuator bracket (Jideco electric actuator system only)
ADD PHOTO SHOWING ALL OF THE ABOVE PLUS THE HARNESS ONCE PRODUCTION BRACKETS AVAILABLE
Subaru used the following four different cruise control systems on the cable throttle engines:
- Vacuum actuator, manifold vacuum. Hardware manufactured by Jideco and Unisia. Used in the SVX and possibly some early ‘90’s Legacies. This system can probably be used, but we don’t have enough information on it to offer the necessary wiring work.
- Vacuum actuator, manifold vacuum via a non return valve and vacuum reservoir. Manufactured by Mitsubishi. The actuator looks like a mini brake servo with a metal casing, and has the solenoid control valves built in. Used from about MY93-96.
- Vacuum actuator, electric vacuum pump. Manufactured by Jideco. This system uses an engine bay mounted electric vacuum pump / valve, connected to a remote vacuum actuator with a hose. This is similar to the Hella system that VW used in the T25/T3/Vanagon and many later VW’s and models from other manufacturers. Used from about MY97-99.
- Electric actuator. Manufactured by Jideco. This system is simpler and neater than either of the vacuum systems. Used from about MY00-07. Not all of the cruise control ECU’s for this application can be used in VW applications. Those which cannot have to be swapped for other part numbers – they’re usually inexpensive, and sometimes we have them in stock. If you’re adding cruise control to an engine from a car which didn’t originally have cruise control, we recommend you use this system. Parts are easier to find, and it has the speed increment / decrement function which some of the earlier systems did not:
In a Subaru, cruise control is never a separate wiring harness – it is always built into the main harness which runs across the width of the car under the dash, containing all the other circuits in the car. Some Subaru models without cruise control do have the necessary wiring (these are mostly the Jideco vacuum pump system), but most don’t.
There is a lot more detail about Subaru cruise control in VW’s is included in the FAQ below: