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Wire "the pin through there" means you need to wire that pin #2 wire through the switch on the top of the clutch pedal.
With cruise on a manual car, as soon as you push the clutch a hair even the ecu will cancel cruise so the rpm's don't shoot up (Cause you are going out of gear).
The only way it can know that is a little switch on the top of the clutch pedal, you have to get upside down almost to see it in the car.
As soon as the pedal moves like a 1/4", this switch is deactivated and is used to cancel cruise.. basically it tells the cruise ecu that "neutral" is happening now.
The reason disconnecting it makes it work, is that it is a reverse switch (normally closed), so pulling that wire out (open) makes it think its not in neutral.
They do this on brake switches etc... so that if the swich fails completely the system won't work.. if it was the other way it would work until you tried to use it and then you would find out the hard way which would be bad.. that would be like if you pulled the wire out completely actually.
Kahn ^^ that is correct. My original 5spd car was wired the same way with nss plug jumpered (paperclip in bottom clutch switch) and cause it had the top clutch switch still (cruise one) everything worked just fine including cruise control.
I even used an aristo auto ecu in that original 5spd car and cruise still worked cause I had the top clutch switch in. still worked also when on a 6spd supra ecu.
Basically you need to wire in the top clutch switch to the auto connector (from there it goes to that pin 2).
You don't have to go to the cruise ecu though, all of those pins you need are on the old auto transmission connector.
Assuming you used a stock pedal, the switch is probably installed and not wired up. So just get a connector and wire it up to the right 2 pins on the auto plug and you should be good to go working like stock.
This works and reflects the diagram you posted because lets say you were cruising in an automatic car in drive and you shifted the auto into neutral... the cruise would cancel because that pin would show neutral, and you would be able to resume once you go back to drive or no neutral showing up. So all of the functions work the same on auto and manuals the wires just run to different places, so what all the transmission swapper's do is run the clutch switch x2 wires to the auto plug cause everything you need to wire goes through that one plug, including reverse wiring.
I assume if you unplug that wire like stockhatch did, when you clutch in the cruise ecu won't know you are in neutral and rpm's could start to rise... or its smart enough itll stop and throw an error code of some sort (if you are lucky). I honestly wouldn't try just pulling the wire, the proper way is to wire up the top clutch switch its really easy and goes to the wires on the old auto plug like shown in that 4runner/tacoma picture I posted above. Might even get lucky and the connector for the automatics might even be similar between those and the SC auto's and then just wire it up like shown above.
^^ that is correct. My original 5spd car was wired the same way with nss plug jumpered (paperclip in bottom clutch switch) and cause it had the top clutch switch still (cruise one) everything worked just fine including cruise control.
I even used an aristo auto ecu in that original 5spd car and cruise still worked cause I had the top clutch switch in. still worked also when on a 6spd supra ecu.
Basically you need to wire in the top clutch switch and it goes to that pin 2, not sure the exact wiring but that is what is going on.. as you can see from the diagram both the manual and auto ecu's use the same wire for the same function. Assuming you used a stock pedal, the switch is probably installed and not wired up. just get a connector and wire it up and should be good to go.
I assume if you unplug that wire like stockhatch did, when you clutch in the cruise ecu won't know you are in neutral and rpm's could start to rise... or its smart enough itll stop and throw an error code of some sort (if you are lucky). I honestly wouldn't try just pulling the wire, the proper way is to wire up the top clutch switch its really easy and goes to the wires on the old auto plug like shown in that 4runner/tacoma picture I posted above. Might even get lucky and the connector for the automatics might even be similar between those and the SC auto's and then just wire it up like shown above.
That's just it. The harness for auto and manual cars at the clutch pedal and brake pedal area are identical. All I had to do was plug them into their connectors. 🤔
I'm thinking it's only wired to the junction point and not to the cruise ECU itself. That's all I can think of at this point.
I have never heard of that before, you sure your car didn't have a manual oiginally? there shouldn't be the 2 clutch switches pre wired... something is up there.
everyone runs the 2 clutch pedal wire switches to the plug for the automatic transmission which is on the auto "engine harness".
This is what I did on my manual swap and had cruise working, but hey what do I know
I have never heard of that before, you sure your car didn't have a manual oiginally? there shouldn't be the 2 clutch switches pre wired... something is up there.
everyone runs the 2 clutch pedal wire switches to the plug for the automatic transmission which is on the auto "engine harness".
This is what I did on my manual swap and had cruise working, but hey what do I know
It's definitely an original dash harness. Automatic NA Supra. It had the connectors right there. I just plugged in. Trust me. It was original. Guy had no idea what he had at the time. 16 year old kid and sold it to buy a Jeep lol. He didn't do anything to it but drive.
Anyways I'll look into wiring this up then. So you're saying to take the wire and put it into the connector at the tunnel where D normally would have been registered?
Assuming that is a supra thing and lets say those connectors are there on autos, there is no guarantee that they are connected all the way through the dash harness to the right area on the body plugs etc... You need to run the 2 wires from the top clutch switch, to the appropriate 2 pins on the auto plug.
Maybe you just plugged in the brake light switch? which is the same on both manual and auto pedals.
I think if you go look at the auto plug on your engine harness (probably tucked under shifter plate in console somewhere, or stuffed in the trans tunnel), you will already see 2 wires jumpered there for starting (that should be run to the bottom switch on the clutch pedal), and 2 more wires there for your reverse light switch on the transmission wired up.
you are just missing the last 2 wires from the top clutch switch, like shown in that tacoma diagram above.
Everyone I have ever read about doing a manual swap in an auto toyota has jumpered at the auto trans plug... if what you are saying is true I could have just pluged in my clutch pedal to an existing wire and it all work, but I have never seen or heard of that, but I have seen and heard of wiring to the auto plug and I have done it on my tacoma, there was no clutch pedal or wiring there.
maybe your car was an n/a 5spd and the kid had an auto engine put in there or something, you never know with these cars, but it should be on the door tag.
here from supraforums talking about jumping the NSS at the auto plug for starting, that is the bottom clutch switch.
I am not sure which 2 pins to wire up the top clutch switch to on a supra, but I bet its 2 of those pins on one of the 2 connectors at the auto trans.
This is what they look like on your engine harness though. https://www.supraforums.com/threads/...wiring.436805/
here from supraforums talking about jumping the NSS at the auto plug for starting, that is the bottom clutch switch.
I am not sure which 2 pins to wire up the top clutch switch to on a supra, but I bet its 2 of those pins on one of the 2 connectors at the auto trans.
This is what they look like on your engine harness though. https://www.supraforums.com/threads/...wiring.436805/
The car has a automatic dash harness, and a 6 speed turbo engine harness. The engine harness also includes the transmission speed sensor as well as the reverse switch.
The wiring for the upper and lower pedals were both there. And the car started right up after I installed the switches. Before it wouldn't run without them. I'm going to look into the connector. There is one at the shifter on top of the tunnel that's got nothing to plug into any more. I'll reference the colors and pins vs the manual to verify its the correct wires and connector.
Well that is really interesting then, never knew about that one and have only had experience with SC's and 6spd supras so far.
You wouldn't have the auto plug with a manual transmission harness, so whoever did your harness already wired the manual trans up to likely the body plug.
In your case then I would guess that you need to catch that signal as it goes through the body plug then.
I would start by getting the pinout of the body plugs, and trying to see where in the schematics that pin 2 from the cuise ecu passes through.
This is the same thing for jumping the NSS to start which is usually done at the auto trans plug on an auto harness, but can be done at the body plug instead if you have a manual harness like you do as most of the signals go through there also. Assuming the supras all have the clutch switches installed and wire up to the body plug, using a manual harness would make it work once plugged in like you are saying assuming whoever did the harness did it right, so it all does make sense now I did not realize you were running a manual harness earlier.
Well that is really interesting then, never knew about that one and have only had experience with SC's and 6spd supras so far.
You wouldn't have the auto plug with a manual transmission harness, so whoever did your harness already wired the manual trans up to likely the body plug.
In your case then I would guess that you need to catch that signal as it goes through the body plug then.
I would start by getting the pinout of the body plugs, and trying to see where in the schematics that pin 2 from the cuise ecu passes through.
This is the same thing for jumping the NSS to start which is usually done at the auto trans plug on an auto harness, but can be done at the body plug instead if you have a manual harness like you do as most of the signals go through there also. Assuming the supras all have the clutch switches installed and wire up to the body plug, using a manual harness would make it work once plugged in like you are saying assuming whoever did the harness did it right, so it all does make sense now I did not realize you were running a manual harness earlier.
What you're saying about my connectors is not correct. That's how the factory did it. Don't ask me why. Look in that thread you linked from Supraforums. I'm TheProPilot. There are others that commented that all the wiring is taped and tucked up in the dash just chilling there waiting to get connected. I venture to say the SC harness is the same thing since a 5 speed option was there. Toyota did my dash harness man. I don't know how else to say that. It's OEM. Original. Not modified. The connectors were were all there - you just have to dig to find them. Toyota tapes them up and away to not get caught up when not in use.
I do have a manual engine harness though. But that only has speed and reverse wiring on the transmission outside the car.
I'll find where the cruise disengage switch travels and link it over to the cruise ECU. At least it isn't a long way to go to link them up.
Thanks again for your help. Worst case I'll pull pin 2 and see if cruise works. If it does then it's definitely the same thing.
I don't think you are making it up and I was agreeing with you there that it sounds like it did come that way factory then, I have just never heard of it before and also I did not realize you were using a manual harness.
If you pull the pin it will bypass the safety of the clutch cancel switch, so when you clutch in my guess the rpms will shoot up, you have to deactivate cruise by tapping on the brake or canceling instead of clutching in doing it automatically.
I don't know the exact wiring, but it looks like that is the spot it runs through then on the body plug, if you still had the auto harness it would have just been easier cause all 6 you need end up at the auto trans plug.
I don't think anyone has posted the info for making cruise work through the body plug on those setups, so I would start looking at the signals going through the body plug.
You are probably right that you could also wire it in right at the cruise control ecu as well and might be easier on your setup to do it that way.
I would probably do that before messing with the body plugs since your harness is already done and installed, but there are probably a few ways to do it.
Right on. That's my mistake then for misunderstanding. I admit the whole thing is confusing.
I'm going to go pull pin 2 once my daughter is up just to be sure I'm onto this correctly. Long story.
So here's one for you then: I tried engaging cruise with my foot off of the pedal like normal. "Cruise" flashes. I then tried pushing the pedal down to activate/deactivate the switch and tried engaging - nothing happened. If I stop the car and try to engage cruise without pressing the clutch pedal "Cruise" does not flash. It only flashes once I'm driving and try to engage it. Does that sound like this issue? Once I have a free minute I'm going to try pulling pin 2, and if it works: I'll just splice in a wire from the top pedal switch output wire (not the yellow) to pin 2 and reinsert it.
I was always under the impression that it was the output shaft speed sensor not getting a speed and that was why it wouldn't engage. I once saw someone had to craft a VR sprocket and wired in a sensor on their driveshaft to get theirs to work. Very interesting.
That sounds like your top cruise control switch is working then, so its probably wired up fine already through the body plugs then which is interesting but sounds like it.
It will only activate with the clutch not being pressed and above a certain speed.
My guess is that when the cruise flashed at you, it was an error of some other kind in the cruise system cause that means it did try to engage it.
You do have the cruise control stuff installed in your engine bay right? the module and the cable going to the throttle body?
just asking cause I think you have a swap and I don't think everyone goes the extra step to install that stuff.
If you did not have the module plugged in in the engine bay, or the cable on the throttle body right, when it goes to engage it will trip an error code and blink at you.
So its making me think in your case you have more of a physical cruise control system issue and not so much the wiring.
Oh and the second speed sensor is only on automatic transmissions (internal tailshaft speed sensor), that is not the main vss used for speed that the cruise control ecu would see, as said lots of us have had manual cars with cruise control working factory and they do not have the second internal speed sensor.
Did you find out if you have the cruise stuff installed with the swap? there should be a second throttle cable on the throttle body going to a module in the engine bay.
so sounds like pin 2 is related to the neutral park switch on autos and clutch cancel switch on manuals, so when cruise sees neutral come on it wont work either way.
alot of auto to manual swaps jump the NSS to be in neutral all the time, so cruise wouldn't work but unplugging that wire makes the cruise not see that you are in neutral (so assumes drive reverse etc.)
So instead of unplugging it, you can install the the top cruise clutch switch, and wire that pin through there so neutral does not go to the cruise ecu when you are in gear, and as soon as you press on the clutch it sees neutral and cancels cruise.
For example, that is how my tacoma was wired up with a manual swap on the auto ecu (before I swapped to a manual ecu) and cruise worked just fine like stock, I didn't have to pull any wires from cruise ecu. see the diagram below there is a depress switch and a release switch (2 switches on clutch pedal).
The pins are different but you get the general idea. you use the bottom clutch switch for starting or bypass like shown in different threads, and the top clutch switch is for cruise control cause it deactivates as soon as you get on the clutch.
Okay so a few questions for making cruise work. Except the wiring diagram you just listed above, is there anything else that needs to be messed with? Im not sure if a ATEMU or having the trans wired to think its in neutral will effect anything?
04-14-20, 03:43 PM
If I stop the car and try to engage cruise without pressing the clutch pedal "Cruise" does not flash. It only flashes once I'm driving and try to engage it. Does that sound like this issue? Once I have a free minute I'm going to try pulling pin 2, and if it works: I'll just splice in a wire from the top pedal switch output wire (not the yellow) to pin 2 and reinsert it.
