Homer Posted February 4, 2014 Share Posted February 4, 2014 My car has a 98 facelift 6spd shell and interior wiring harness, plus a UK engine & auto box with auto engine bay wiring loom and ECU. Since the interior dash looms are manual I understand the connectors for the auto shifter won't fit. Is this going to stop the car from being able to drive? Excuse my ignorance, but why can the car no drive when "D" is selected, surely it's all a mechanical process... Any ideas/thoughts? Quote Link to comment Share on other sites More sharing options...
Kaan W Posted February 4, 2014 Share Posted February 4, 2014 There's no wires that go to the shifter itself, all the autobox electrics are part of the engine loom which goes through the bulkhead to the ecu. I assume thats what you meant? Quote Link to comment Share on other sites More sharing options...
Homer Posted February 4, 2014 Author Share Posted February 4, 2014 Well yes, sort of. There's two connectors on the shifter unit, (one blue and one white), the blue plug fits but the white one doesn't. It was mentioned by someone else in another thread that the car would be able to be started, but not driven without the auto interior loom, but I don't understand why.... Quote Link to comment Share on other sites More sharing options...
Kaan W Posted February 4, 2014 Share Posted February 4, 2014 Ahh I see, ive not noticed them, I'll have a flick through the pdf. I know the ecu controls how it performs so I would have thought it would drive as normal, unless the plugs for the dash loom is for the speedo gear position and od lights? Quote Link to comment Share on other sites More sharing options...
natony Posted February 4, 2014 Share Posted February 4, 2014 I've got a complete auto dash with dash loom just sat here doing nothing Quote Link to comment Share on other sites More sharing options...
Homer Posted February 4, 2014 Author Share Posted February 4, 2014 Ahh I see, ive not noticed them, I'll have a flick through the pdf. I know the ecu controls how it performs so I would have thought it would drive as normal, unless the plugs for the dash loom is for the speedo gear position and od lights? Thanks Kaan and yeah, this is the same I'm assuming too. Apart from the start lockout I can't see how those plugs on the shifter have anything to do with the box being able to engage drive. I've got a complete auto dash with dash loom just sat here doing nothing Thanks Tony, if it comes to that I might as well just crack on and fit the manual box. The only reason for trying this was to make it easier for the manual conversion Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted February 4, 2014 Share Posted February 4, 2014 Selecting a gear is a mechanical process, letting the ECU know its on P or N so it will start is electric, as is PWR mode (not sure the Supra has that?) As is overdrive. The neutral/start switch on the side of the auto also send indication to the dash so you can see what gear you're in. Quote Link to comment Share on other sites More sharing options...
Homer Posted February 4, 2014 Author Share Posted February 4, 2014 Thanks Swampy. The car starts so I know there's no electrical lockout issue. I'm not concerned about the signals to the gear selector lights as the clocks are manual anyway. I just need to find out if there's any issue with those sockets not being connected. The engine bay loom and ECU and auto so my simple logic is it should work... Quote Link to comment Share on other sites More sharing options...
garethr Posted February 5, 2014 Share Posted February 5, 2014 If the ECU isn't connected to the gearbox solenoids you can change gear manually, but, according to http://www.autoshop101.com/forms/AT25.pdf: L = Low (1st) 2 = 3rd D = overdrive (4th) Quote Link to comment Share on other sites More sharing options...
Homer Posted February 5, 2014 Author Share Posted February 5, 2014 Thanks Gareth, very useful, that might help in case it doesn't like Drive. I will keep in mind when trying to move it at the weekend. The connector on the box itself is plugged into the engine bay wiring loom and therefor ECU, but I have no kick-down switch so manual shifting might be needed. If I read the pdf you linked to correctly it will work without the shifter mechanism plugs disconnected. I guess I will find out soon Quote Link to comment Share on other sites More sharing options...
Homer Posted February 7, 2014 Author Share Posted February 7, 2014 Today I tried to get it in gear and see if it would move, but when moving the shifter with the engine running the box doesn't actually manage to select any gears. There's none of usual little thud you get when going through them (I tried them all). Is there some sort of setup process needed with the gear selector to get it connect correctly to the box? Quote Link to comment Share on other sites More sharing options...
GMan Posted February 7, 2014 Share Posted February 7, 2014 Supra auto boxes need the ecu connected as gear selection is electronic not manual For example I can pop it into 2 at over 120kph and it will hold 3rd gear untill my revs drop below 6800 to shift down. Also tc lock up is managed by the ecu. Quote Link to comment Share on other sites More sharing options...
David P Posted February 7, 2014 Share Posted February 7, 2014 Manually it will be selecting gears, but without electrickery to the solenoids there will be no fluid pressure to engage the clutch plates or work the torque convertor. Quote Link to comment Share on other sites More sharing options...
Homer Posted February 7, 2014 Author Share Posted February 7, 2014 Okay, that makes sense, thanks. The ECU is auto along with the engine loom, is that where the connectors are for the auto gearbox? Or, are they on the selector mechanism itself? Quote Link to comment Share on other sites More sharing options...
David P Posted February 7, 2014 Share Posted February 7, 2014 (edited) There's a connector block on the transmission and 3? sensors, just plug the original loom back in. If the loom has been converted to manual, the 2 reversing light wires will have been joined together. Just return them to stock. Edited February 7, 2014 by David P (see edit history) Quote Link to comment Share on other sites More sharing options...
GMan Posted February 7, 2014 Share Posted February 7, 2014 There's a connector block on the transmission and 3? sensors, just plug the original loom back in. If the loom has been converted to manual, the 2 reversing light wires will have been joined together. Just return them to stock. This, there is one big connector that is all of the control stuff and two speed sensors Mine is an NA but I am pretty sure, externaly anyways, tt and na boxes are very smilar Quote Link to comment Share on other sites More sharing options...
David P Posted February 7, 2014 Share Posted February 7, 2014 Yes, but it still wont function without the speed sensor and fluid temp signals. Quote Link to comment Share on other sites More sharing options...
Homer Posted February 7, 2014 Author Share Posted February 7, 2014 Thanks both, I'll have a look over the weekend. Do you know if that connector block is part of the engine loom? The body and engine BAY loom is still manual, I'm really hoping it's not on either of those! Quote Link to comment Share on other sites More sharing options...
David P Posted February 7, 2014 Share Posted February 7, 2014 The transmission loom is part of the engine loom. If it's the original auto loom it should be there tied up out of the way, however, if it's been swapped for a manual loom, your stuffed. Quote Link to comment Share on other sites More sharing options...
GMan Posted February 7, 2014 Share Posted February 7, 2014 Thanks both, I'll have a look over the weekend. Do you know if that connector block is part of the engine loom? The body and engine BAY loom is still manual, I'm really hoping it's not on either of those! The transmission loom is part of the engine loom. If it's the original auto loom it should be there tied up out of the way, however, if it's been swapped for a manual loom, your stuffed. looks like you will need the auto loom mate, I have a spare loom that I am hesistant to part with as it is in better shape than my original loom and I meant to replace it a while ago but decided that if it wasn't broke i wasn't going to fix it. So in the remote possiblity you cant get one let me know. Quote Link to comment Share on other sites More sharing options...
Homer Posted February 7, 2014 Author Share Posted February 7, 2014 Good stuff. It's an auto engine loom (UK) so I guess is not plugged in. I'm having a look at the wiring diagrams now, there's a fair bit more involved that I first thought. Something is connected somewhere as the shift lock is working (i.e. if I select drive it won't turn the engine over, in park or neutral it's okay. Quote Link to comment Share on other sites More sharing options...
Homer Posted February 7, 2014 Author Share Posted February 7, 2014 looks like you will need the auto loom mate, I have a spare loom that I am hesistant to part with as it is in better shape than my original loom and I meant to replace it a while ago but decided that if it wasn't broke i wasn't going to fix it. So in the remote possiblity you cant get one let me know. Thanks, very good of you Just to be clear: Engine loom: UK Spec Auto Engine Bay loom: VVTI Manual Body Loom: VVTi Manual Quote Link to comment Share on other sites More sharing options...
Homer Posted February 7, 2014 Author Share Posted February 7, 2014 David, Gman, hope I can pick your brains here. Is the Park/Neutral switch relevant to being able to engage drive? I think this is the switch on the handbrake. I can't imagine the ECU wouldn't allow the gearbox to engage drive with the handbrake on, but it seems to be quite critical in the wiring diagrams. That switch is currently removed from the handbrake as the prats who did the trans tunnel mod mounted the plate too far over meaning the sensor doesn't fit. I can work around that with something custom (i.e. bodge!), but it's not clear how relevant it is to being able to select drive. Quote Link to comment Share on other sites More sharing options...
David P Posted February 7, 2014 Share Posted February 7, 2014 (edited) The handbrake switch only lights the bulb on the dash, it has no transmission function. Find the loom and plug it in, that'll get everything working except maybe the reversing light if the 2 wires have been altered. Edited February 7, 2014 by David P (see edit history) Quote Link to comment Share on other sites More sharing options...
Homer Posted February 7, 2014 Author Share Posted February 7, 2014 Thanks David, I'll cross that off the list. I've had a look at the trans sockets you mentioned. The speed sensor and the main plug are connected up to the engine loom. I need to check further but it does look like everything is plugged in. The only bits not plugged in are two sockets on the shifter mechanism. The blue plug can be connected, but the other (white plug) is a different size and shape with a different number of connection points Quote Link to comment Share on other sites More sharing options...
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