SC400 5speed question regarding ECU
#16
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yeah i think to describe it as a slight hesitation in the low gears is pretty accurate.
I actually kind of like it driving around town it makes things really smooth when you shift.
feels sort of like a luxury mode for a manual trans kinda matches the lexus feel.
when you get on it though the problem will clear up which is when you need it to really.
Its not perfect but it shouldn't stop you from swapping to a manual trans its still much better than an auto.
Its either that or a standalone, I would try and run a megasquirt on it personally but it will require a fair amount of wiring.
for you guys that originally had autos, I wonder if pressing the power mode button helps at all.
I don't have that button but I know the pin on the ecu for it and could wire one up.
I actually kind of like it driving around town it makes things really smooth when you shift.
feels sort of like a luxury mode for a manual trans kinda matches the lexus feel.
when you get on it though the problem will clear up which is when you need it to really.
Its not perfect but it shouldn't stop you from swapping to a manual trans its still much better than an auto.
Its either that or a standalone, I would try and run a megasquirt on it personally but it will require a fair amount of wiring.
for you guys that originally had autos, I wonder if pressing the power mode button helps at all.
I don't have that button but I know the pin on the ecu for it and could wire one up.
Last edited by Ali SC3; 10-18-13 at 03:27 PM.
#17
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#18
I read a few days ago that the hesitation comes from wiring the ECU to think its in Neutral when in gear. Apparently wiring it to think its in Drive fixes the hesitation.
Dont quote me on that though, I read it in a thread but cant remember which one.. just FYI.
I will definitely be diving into this swap once I get the money for it. Fortunately I have a few options where I can get it done that I trust will know how to tackle any issues.
Dont quote me on that though, I read it in a thread but cant remember which one.. just FYI.
I will definitely be diving into this swap once I get the money for it. Fortunately I have a few options where I can get it done that I trust will know how to tackle any issues.
#19
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I was wondering about that, I was thinking the opposite mine must be thinking its in drive why else would it shift because in neutral it would probalby not shift, so maybe there is a way to make the ecu think its in neutral. gotta be one or the other might get rid of it but I still hardly notice it after driving it like that for a year or so. much better than the auto either way.
#20
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All righty, I'm not here too much any more. Anyway, so I used to have a 92 SC400 with a W58. No check engine lights at all for me. Stock ECU as well.
I did go Adaptronic in the end (shameless plug) which I still have (with the map/iat sensor). I never got the car pro-tuned, but I got it enough. The car ran great either way though.
I did go Adaptronic in the end (shameless plug) which I still have (with the map/iat sensor). I never got the car pro-tuned, but I got it enough. The car ran great either way though.
#21
I was wondering about that, I was thinking the opposite mine must be thinking its in drive why else would it shift because in neutral it would probalby not shift, so maybe there is a way to make the ecu think its in neutral. gotta be one or the other might get rid of it but I still hardly notice it after driving it like that for a year or so. much better than the auto either way.
I personally did this swap so here's a little help...
You MUST install a switch or relay to start the car in PARK then switch to DRIVE before accelerating. If you don't then the car won't drive smoothly and you'll get a cel. I think if you set it to NEUTRAL all the time you'll end up with the same hesitations. If you're in DRIVE all the time you'll get a cel. I think your buddy might have pulled the cel bulb out. The only cel I have is for Speed Sensor A which I'm guessing was on the auto trans. But the speedo works so I'm happy. My car drives like factory with no hesitation. Use this method and you'll be a happy man
You MUST install a switch or relay to start the car in PARK then switch to DRIVE before accelerating. If you don't then the car won't drive smoothly and you'll get a cel. I think if you set it to NEUTRAL all the time you'll end up with the same hesitations. If you're in DRIVE all the time you'll get a cel. I think your buddy might have pulled the cel bulb out. The only cel I have is for Speed Sensor A which I'm guessing was on the auto trans. But the speedo works so I'm happy. My car drives like factory with no hesitation. Use this method and you'll be a happy man
#22
Lexus Champion
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well I def buy park and neutral being the same as it goes to the same pin on the ecu for sc300/supras (400 will be similar operation all toyota/lexus are).
pin 76 http://wilbo666.pbworks.com/w/page/4...0JZA80%20Supra
so the question is how to get it to be in drive? it seems you would want to apply ground to be in park or neutral to that pin, so then to be not in that you would just not apply ground to that pin or possibly even apply battery voltage to that pin? I would think interrupting the ground with a simple switch on that line would do the trick like that guy mentioned above, but you would need to flip it after starting as you maybe can't start the car without that pin connected unless there is some possibly re-wiring that can be done.
pin 76 http://wilbo666.pbworks.com/w/page/4...0JZA80%20Supra
80 Pin Plug 76 NSW Neutral & Park Switch Auto Position Indicator Input This pin is used to determine if the automatic transmission shifter is in the Park or Neutral positions. The engine ECU needs to energise/de-energise the automatic transmission solenoids to select the correct gear.
Automatic transmission: This pin is connected to Ground by the Starter Relay coil via the automatic shifter position switch when the automatic transmission shifter is in the 'N' or 'P' positions.
Manual Transmission: This pin is connected to the engine ECU STA pin inside the engine wiring loom and hence is connected to battery voltage when the ignition switch is in the CRANK position. When the engine is not being cranked this pin is connected to Ground via the Starter Relay coil
Automatic transmission: This pin is connected to Ground by the Starter Relay coil via the automatic shifter position switch when the automatic transmission shifter is in the 'N' or 'P' positions.
Manual Transmission: This pin is connected to the engine ECU STA pin inside the engine wiring loom and hence is connected to battery voltage when the ignition switch is in the CRANK position. When the engine is not being cranked this pin is connected to Ground via the Starter Relay coil
#23
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All righty, I'm not here too much any more. Anyway, so I used to have a 92 SC400 with a W58. No check engine lights at all for me. Stock ECU as well.
I did go Adaptronic in the end (shameless plug) which I still have (with the map/iat sensor). I never got the car pro-tuned, but I got it enough. The car ran great either way though.
I did go Adaptronic in the end (shameless plug) which I still have (with the map/iat sensor). I never got the car pro-tuned, but I got it enough. The car ran great either way though.
#24
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Just gonna throw in my .02 if it helps anybody here. I did my swap almost a year ago (92 sc400). What I used for both starting the car In neutral then switching it to drive is I used a mechanical limit switch that has 2 common inputs and a normally open and normally closed output for each of those inputs, all in 1 switch. I work in the industrial door business and these are commonly used on commercial openers. So I wired 1 input of the switch to the NSS terminals at the trans plug (normally closed) then wired the 12v supply from the trans plug to the other input on the switch, and wired it to the L terminal of the trans plug (normally open). Clear as mud?? Lol. Now..this switch I mounted so it is activated by my e-brake so:
E-brake up = switch not activated (NSS connected, "L" disconnected) car starts.
E-brake down = switch activated (NSS disconnected, "L" connected) ECU thinks car is in gear.
I chose the "L" gear position at the trans plug so the ECU isn't expecting a gear change like it would be in the "D" position. Works like a charm ALSO cruise control works too (even at highway and higher speeds!). I could have also wired the switch so the car sees "P" as well as NSS with e-brake up so memory seats work too but I haven't crawled under and done it. Keep in mind my car is a 92 (no Vvt-i) but it solved the issues that would've bugged me once the car was swapped.
E-brake up = switch not activated (NSS connected, "L" disconnected) car starts.
E-brake down = switch activated (NSS disconnected, "L" connected) ECU thinks car is in gear.
I chose the "L" gear position at the trans plug so the ECU isn't expecting a gear change like it would be in the "D" position. Works like a charm ALSO cruise control works too (even at highway and higher speeds!). I could have also wired the switch so the car sees "P" as well as NSS with e-brake up so memory seats work too but I haven't crawled under and done it. Keep in mind my car is a 92 (no Vvt-i) but it solved the issues that would've bugged me once the car was swapped.
#26
Just gonna throw in my .02 if it helps anybody here. I did my swap almost a year ago (92 sc400). What I used for both starting the car In neutral then switching it to drive is I used a mechanical limit switch that has 2 common inputs and a normally open and normally closed output for each of those inputs, all in 1 switch. I work in the industrial door business and these are commonly used on commercial openers. So I wired 1 input of the switch to the NSS terminals at the trans plug (normally closed) then wired the 12v supply from the trans plug to the other input on the switch, and wired it to the L terminal of the trans plug (normally open). Clear as mud?? Lol. Now..this switch I mounted so it is activated by my e-brake so:
E-brake up = switch not activated (NSS connected, "L" disconnected) car starts.
E-brake down = switch activated (NSS disconnected, "L" connected) ECU thinks car is in gear.
I chose the "L" gear position at the trans plug so the ECU isn't expecting a gear change like it would be in the "D" position. Works like a charm ALSO cruise control works too (even at highway and higher speeds!). I could have also wired the switch so the car sees "P" as well as NSS with e-brake up so memory seats work too but I haven't crawled under and done it. Keep in mind my car is a 92 (no Vvt-i) but it solved the issues that would've bugged me once the car was swapped.
E-brake up = switch not activated (NSS connected, "L" disconnected) car starts.
E-brake down = switch activated (NSS disconnected, "L" connected) ECU thinks car is in gear.
I chose the "L" gear position at the trans plug so the ECU isn't expecting a gear change like it would be in the "D" position. Works like a charm ALSO cruise control works too (even at highway and higher speeds!). I could have also wired the switch so the car sees "P" as well as NSS with e-brake up so memory seats work too but I haven't crawled under and done it. Keep in mind my car is a 92 (no Vvt-i) but it solved the issues that would've bugged me once the car was swapped.
Good idea on using the L instead of D. I will try it on my car this weekend and see if it makes any difference at all.
Using D can cause some issues because the solenoid will constantly try to open and close based on the speed and RPM. Having it in L should lessen the problem because the transmission will not try to switch any solenoid on or off.
I have my NSS switch connected to the clutch pedal instead, Car will only start with the clutch pedal depressed.
PS: My car is OBD2, i needed to have the solenoid harness of the transmission connected to the car in order to avoid getting the CEL. Just make sure you ground the 2 first solenoid on the chassis and the CEL will go away.
For the people who have the OBD2 vehicle and want to do a manual swap without getting a CEL, it is indeed possible.
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