Ibreakstuff Posted January 5, 2013 Share Posted January 5, 2013 So i've been driving my 1990 loyale with a 5mt swap (fwd) for a couple years now. Its smog time again (california); so instead of taking the dash apart again to hack the check engine light again I am looking to fix the issue properly.. I am wondering, what exactly tells the ECU that the car is auto/manual? Is there a pin that needs to be grounded or jumped? I've scoured over hundreds of forum posts and the manuals I have access to and cannot find the exact solution. Notes: -Car was originally FWD 3AT -Currently swapped 5MT fwd -Currently using an ECU from a 5MT loyale (still thinks its automatic) -Only showing ECU codes 08 (ca automatic) and 51 (neutral switch) I'm tempted to do a full wiring swap, as I already have the bulkhead harness from a 5mt loyale.. Which would give me the correct transmission connectors. But swapping the body harness doesn't sound like much fun. Anyone familiar with this? Most people seem to just jump the inhibitor switch and call it done. 1 Link to comment Share on other sites More sharing options...
jono Posted January 6, 2013 Share Posted January 6, 2013 Can't see that Subaru would change things that much between the years and models. If it helps, a few years earlier the EA82 L Series ECU with three plugs 85 and 86 models it was a simple ground or not grounded pin on the ECU. What is it doing that makes you aware it thinks it is still an auto? Link to comment Share on other sites More sharing options...
Ibreakstuff Posted January 6, 2013 Author Share Posted January 6, 2013 Can't see that Subaru would change things that much between the years and models. If it helps, a few years earlier the EA82 L Series ECU with three plugs 85 and 86 models it was a simple ground or not grounded pin on the ECU. What is it doing that makes you aware it thinks it is still an auto? I wish I could figure out which pin that would be, looking at the schematics I can't seem to find it. It definitely still thinks its auto tho per the 08 identification code, would show code 07 if it was cali manual (which is what the ecu came from). In "auto" mode the neutral switch is on to start, then off when in gear. In manual mode it is reversed, so currently I am not able to wire in the neutral switch directly from the transmission. Also in auto mode, if the switch is continuously on it gives a CEL and code 51. I guess I could just wire in a toggle switch to the inhibitor for starting only, this to prevent it from popping the 51 code (at least to smog). The only adverse effects that I have noticed day to day are a higher than normal idle and lifting off throttle too fast will try to throw my face into the steering wheel. I believe both of these would be resolved with the correct fueling from the ECU with a working neutral switch. Maybe my understanding of how it works is skewed, please someone correct me if I an wrong. Link to comment Share on other sites More sharing options...
86BRATMAN Posted January 6, 2013 Share Posted January 6, 2013 do you still have the tcu plugged in, or does that even apply to the 3at Link to comment Share on other sites More sharing options...
TomRhere Posted January 6, 2013 Share Posted January 6, 2013 Been digging thru diagrams myself, trying to clear some errant codes. Not sure if it's what you'll need but got a few wires for you to check on the connection to the ECU. This is on the middle connector plug. Looking at it from the wiring side, catch-clip up. Pin #1 top row left side, Blue/green wire, AT kick-down control. Pin #13 bottom row 4th position from left side, Yellow/red wire, AT inhibitor switch. Neither of those wires are present in the connector on a Manual trans car. Or atleast they're not on my '88 GL Wagon or the '92 Loyale Wagon, both are Manuals. Link to comment Share on other sites More sharing options...
ivans imports Posted January 6, 2013 Share Posted January 6, 2013 the front car wire harnes is a bugger to change but not impossibble takes about 3 hours and have to pull bumper and both front fenders and dash and i whould change the whole front harness leave the rear harness alone Link to comment Share on other sites More sharing options...
Ibreakstuff Posted January 6, 2013 Author Share Posted January 6, 2013 do you still have the tcu plugged in, or does that even apply to the 3at No TCU on the 3at Been digging thru diagrams myself, trying to clear some errant codes. Not sure if it's what you'll need but got a few wires for you to check on the connection to the ECU. This is on the middle connector plug. Looking at it from the wiring side, catch-clip up. Pin #1 top row left side, Blue/green wire, AT kick-down control. Pin #13 bottom row 4th position from left side, Yellow/red wire, AT inhibitor switch. Neither of those wires are present in the connector on a Manual trans car. Or atleast they're not on my '88 GL Wagon or the '92 Loyale Wagon, both are Manuals. Thanks for the lead Tom, the kickdown control seems like a good suspect. I'll test those pins today. Link to comment Share on other sites More sharing options...
Wayback Posted January 6, 2013 Share Posted January 6, 2013 For an AT SPFI, ECU pin 32 is grounded. To make it an MT, you need to cut that wire. It's a black/red on the largest of the 3 ECU connectors, second from one end between a brown and a light green. Link to comment Share on other sites More sharing options...
Caboobaroo Posted January 6, 2013 Share Posted January 6, 2013 Nw ant to do it the easy way? I believe the 6 pin connector that plugged into the original automatic shifter needs to have a jumper wire installed. Out of the 6 wires, find the two largest and put a wire to connect them. I then wrapped the jumper wire and the connector with electrical tape to keep the jumper secured. This was on my '87 but I don't see it being that much different. Wires should be Black/Yellow stripe and Black/Red stripe. Link to comment Share on other sites More sharing options...
Ibreakstuff Posted January 7, 2013 Author Share Posted January 7, 2013 the front car wire harnes is a bugger to change but not impossibble takes about 3 hours and have to pull bumper and both front fenders and dash and i whould change the whole front harness leave the rear harness alone Its a lot easier if you just pull the headlights, then you don't have to pull the bumper/fenders. The hardest part to reach being the plastic ties on the lower radiator support. I got away without pulling the dash too, but the driver side fender liner does have to come out. And installing it would probably be a hell of a lot harder! I have learned so much in the last couple years from pick-n-pull lol. Nw ant to do it the easy way? I believe the 6 pin connector that plugged into the original automatic shifter needs to have a jumper wire installed. Out of the 6 wires, find the two largest and put a wire to connect them. I then wrapped the jumper wire and the connector with electrical tape to keep the jumper secured. This was on my '87 but I don't see it being that much different. Wires should be Black/Yellow stripe and Black/Red stripe. This is what I did and has been running for the past year or 2, the problem is that it pops a CEL (code 51). And runs a bit weird. The CEL and high idle keeps me from passing smog, tho there are ways to get around that. For an AT SPFI, ECU pin 32 is grounded. To make it an MT, you need to cut that wire. It's a black/red on the largest of the 3 ECU connectors, second from one end between a brown and a light green. This is what I was looking for!!! Thank you so much, I'll give this a try in the AM and post back with confirmation. Now that I take a second look at the wiring diagram.. I do see that pins 32, 1, 46, and 13 are designated for AT. I feel dumb that I did not see these before. Link to comment Share on other sites More sharing options...
markjw Posted February 26, 2016 Share Posted February 26, 2016 (edited) This is what I wayou s looking for!!! Thank you so much, I'll give this a try in the AM and post back with confirmation. Now that I take a second look at the wiring diagram.. I do see that pins 32, 1, 46, and 13 are designated for AT. I feel dumb that I did not see these before. I'm wondering if ever sorted out your erratic idle after you did the swap. I'm having the same dilemma. Also, did you ever look into pins 1,13 and 46. Edited February 26, 2016 by markjw Link to comment Share on other sites More sharing options...
markjw Posted February 26, 2016 Share Posted February 26, 2016 One thing is for certain, at least on my car, jumpering the two fat wires together at the shifter console is a Bad Idea. I've had to remove the jumper after startup or the ecu freaks out when I start driving. Link to comment Share on other sites More sharing options...
markjw Posted February 28, 2016 Share Posted February 28, 2016 (edited) So, I've followed some of the advice of this thread and managed to get the idle somewhat under control. You can leave the fat wires connected, but you have to cut the inhibitor switch wire on the ecu harness. At least then the ecu functions normally. Previously, I left the fat wires connected with the inhibitor switch wire still connected to the ecu, that was causing wild idle fluctuations. At this point I think the idle isn't perfect like it should be, but the car is drivable and throwing no codes. If anyone has any ideas for me, please share. Thanks! Edited February 28, 2016 by markjw Link to comment Share on other sites More sharing options...
wagonist Posted February 28, 2016 Share Posted February 28, 2016 I also would like some similar advice for the 4EAT to manual swap. There's a lot more wiring in the harness than for the 3AT, but I can't just swap looms because of the digi dash & other JDM goodness that wasn't available on local cars. Link to comment Share on other sites More sharing options...
markjw Posted March 3, 2016 Share Posted March 3, 2016 In the end, I disconnected the electrical connections to the IACV. Aside from having to depress the accelerator a little on cold start up, it's running near perfect now. The idle is sweet (after warm-up) but of course it's throwing a CEL code. I can live with it until I sort thru why following the recommended advice on the board here isn't working out too well for me Link to comment Share on other sites More sharing options...
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