spiners210

Hello,
I am new in this forum. I am actually from germany so forgive my english. My car is the only registered JDM Hatch in germany so no one can answer my question over here unfortunately.
I have a 2008 STI from japan and want to retrofit cruise controll. I allready installed the steering wheel buttons. But that diddn't do much. When i push "cruise" and then "set" It will not hold the current speed. I don't think that I have the Cruise light in the dash though, but I have the same brake light switch as the models with CC and since It's a Keyless I also have the swith on the clutch pedal to start the car. A friend of mine has a 2007 JDM spec B Legacy and he just had to install the steering wheel switches and it worked (even without the lights in the Dash)
Is there anything else I have to instal to make it work? Do I have to do anything software wise?
Thank you

Don Clark

The cruise control function is controlled by the main ECU and has the following data reading entries.





I would think it's something you need to have checked with Subaru Select Monitor.

Also worth checking these readings

spiners210

Thanks a lot for the quick reply.
What exactly is Subaru Monitor? Is it a Software where I can read and write on the ECU via OBD?
So first I have to check if theese options are available and set in the ecu?
Then I have to measure the voltage on the ECU pins for B20, C25 and C31? (Does every model have the neutral position switch?)

spiners210

I checked the ECU with free ssm (a free basic tool)
And I found out that I have a neutral position switch and that it works. So I have a Brake switch, clutch switch and neutral position switch and all do work.
I can not program anything with this tool so I was not able to check the selectable options you posted before. But strangely when it connects to the ecu it says that there is a cruise control (GRA in the picture).

spiners210

Sorry for spamming but I checked the 2008 Impreza Service manual and under "Cruise control System" it lists 6 components for the manual transmission version (which my STI is):
(1) Engine Control Module - Have to check
(2) Cruise Control Switch - installed
(3) Stop Light & Brake Switch - works
(4) Cruise indicator light - non existend in my dash (but I don't think that it's really necessary)
(7) neutral position Switch - works
(8) clutch switch - works
So everything but the Cruise indicator light is there. Could you confirm my guess that I have to activate the switches in the main ecu via Subaru Select Monitor?
If yes I will make an appointment at my dealer and see if he can do it.

Don Clark

Free SSM will probably be too basic as it won't have the specific module/s.

http://blog.obdii365.com/2019/06/26/...elect-monitor/

SSM 3 required




After some searching I found this JDM wiring diagram for cruise control switches on the S-GT version

Lefthand side double pole brakelight switch.

Probably worth checking out continuity and whether ECU terminals correspond

Don Clark

For the N/A US model

This from the WRXSTI manual




If you read further into your cruise control section of the US manual you will find a Schematic diagram of the system and it shows that the body integrated unit has some input. (pagesCC6/CC7)

It maybe that the BIU needs to be told that Cruise control is fitted.(although not totally sure but something you may need to look into along with SSM3)

spiners210

So I guess there is no way around disassemlbe everything in the footwell and lay the ecu free.
I don't really understand the jdm diagramm.
Could you please explain wich pins I have to check.
A, B, C and D are the sections on the back where the wire harness go in the ECU. So according to your table on the first post I have to meassure pin B24 on the backside of the ecu when pressing the "set" button for example and it should show 1 Volts right?
Thank you

spiners210

I meassured pin B24 for today with ignition on but no response from the ecu. Pressed every button on the steering wheel but showed 0V the whole time.
Guess next step is to check the Body Integration Unit wit SSM and see if i can activate the Cruise Controll via Software.

Don Clark

Just for completeness below are the Cruise Control wiring diagrams for a UK RHD MY08/09 WRXSTI.
Comparing the first diagram with the JDM version already posted, the JDM diagram does not include the clutch switch (as it's for an auto) and ECU terminal c31 connects to the transmission ecu (TCU) which takes the place of the manual's neutral position switch.
Was your friends Legacy SpecB an auto??

spiners210

Yes he has an auto
What does that mean in conclusion?
Is there even a jdm MT cruise control Wiring diagramm?
I do Have both. The neutral position switch and the clutch switch. Checked them with freessm. They both work. (Sends out "OFF" when in gear and "ON" when in neutral, The clutch switch sends out "OFF" when clutch engaged and "ON" when clutch pedal pressed)

Don Clark

Maybe that's why it worked "straight out of the box" ??

spiners210

Could be, yes. But my car has all the necessary hardware (except for the light in the dash, which he also not have).
Why should cruise control allready be activated in the jdm BIU of an auto but not at an MT.
I know for fact that you only have to retrofit the switches on the EU Hatch models and it works. Why should the jdm models be any different

Don Clark

Because it's what Subaru specify for Japan.

Not all JDM WRXSTI's are the same. It depends upon which "option packs" are requested at build time. Japan has far more combinations of options than Europe ever had.
Just those available for Revision "A" models





Which versions need the switches retrofitted??
AFAIK both UK and the Rest of Europe 2.5L WRXSTI had both the audio controls and CC as standard on the steering wheel.

aaron5178

Hi,

I'm new to this forum and interested in the info above, as have a JDM 2008 Subaru Legacy Spec B.

I have installed all required cruise control functions, however it's not working. I think I'm having some issues as above - did @spiners210 ever come up with a solution?

Look forward to your reply.

Cheers

Aaron

aaron5178

Also to add, I've installed the following components;- Cruise control buttons on steering wheel (8 pin) - buttons light up etc.

- Installed 4 pin brake/ light switch

- Wired a 12v feed to C25 (clutch switch)

- Wired from brake switch to B20 on ECU plug

- Reinstated brown/ blue/ white wires for brake lights from original 2 pin stop light switch
- No cruise control lights on dash, however know people have been successful in the past without it

@Don Clark

Julian Layton

Did you end up getting this working?

Cheers
Julian

Julian Layton

Hey Spiners210,

Did you get this working?
Cheers