93-94 ECU part numbers?
01-26-10, 09:34 PM
#1
93-94 ECU part numbers?
My 94 ECU part number is 89661-50142. I've been doing research and it seems like 93-94 came with either 89661-50140, 89661-50141, 89661-50142. I understand one of these is California specific, not sure which. I need to know if any of these are compatible.
02-08-11, 04:13 PM
#3
A friend has a spare 1UZ ECU from a motor swap he's doing and heard I'm looking for one (ECU) for my pretty much undrivable 94 LS400 so he tried looking up the LS ECU's in alldata and they claim the following, which isn't very helpful...
1994 LS400 89661-50142 (only the one is listed, no mention of TRAC)
1993 LS400 with TRAC 89661-50032
w/o TRAC 89661-50042
They didn't mention TRAC at all for the 1994 model and no mention of the Cali versions at all.
His ECU is a 93 with TRAC so I don't know if my 94 W/O TRAC car is going to like it or not but we'll find out when the usps delivers it to me later this week since he lives 3 hours away from me.
Assuming it's not a bad ECU too, we figure I'll have a lit CEL and trac related diag error codes at all times due to my car's lack of any TRAC components and everything else may be fine otherwise and get me back on the road again, or drivability may be a little wierd if I hit a situation where I get some wheel-spin which the ECU would feel needs the TRAC system, or at the worst that ECU might go into "limp it home" mode if it gets too upset about the missing TRAC components, but we'll see...
I went "yarding" yesterday and out of EIGHT 90-94 LS400's that FIVE of which were 1993 models only ONE still had its' ECU and someone had ripped the dash open to get to it but left it mounted and connected, and for some stupid reason they took the cover off and left it like that with a broken window and it had gotten rained in, damit!
That LS was a 93 with the exact same option packages mine has and was probably one of the ECU models I needed but it was in pieces and wet inside so I didn't even want to try it.
Then I found 2 LS400 ECU's laying loose in the trunk of a 91 with 2 different part numbers and google'd them on my phone while standing at the car in the junkyard.
One P/N search said 91-92 so I left it there. The other said 93 in google but didn't say anything about TRAC or no TRAC and I had no way to tell which 93 it had come out of since it was hidden loose in the trunk of a 91 and of course top top it all off it had yellow junkyard writing on it like it had already been bought and returned but for $30 with a 30 day return option and all the screws still marked with the paint pen to indicate that it probably hasn't been opened up and being the only one that was there and intact I didn't have much choice in the matter.
Oh, and it's a 89661-50141 versus the 50142 alldata part number which leads me to believe it's from a 94 instead of a 93 but I have no clue whether it's for TRAC or no TRAC or possibly a Cali version yet.
My 94 LS400 is apparently a base-model with only the sunroof option. No TRAC or VSC or CD changer or even any seat presets and the tilt is power but the telescopic is manual like the 3rd gen 86.5 - 92 Supras have, and thank god it didn't get the "bag phone" option chewing up the center console bin like EVERY 93 at the yard had but the very cleanly designed and installed steering wheel mounted volume/mute/answer buttons and mic for the bag phone on the left side of the wheel in those cars was pretty cool to see and 'ya gotta love that vintage retro-80's giant cell phone handset with the wired coily cord tucked neatly away on its "cradle" in the center console that was just so cheezy-cool luxury looking for sure!
and I LOVED the actual regular key on/off lock mechanism on the main cell unit in the trunk to prevent unauthorized use of the phone and the phone lock key was still in one of the cars too! The joys of 'yarding...
But anyway...
My 94 LS400 appears to have what I believe are two separate issues/problems, both of which I believe and hope are flaky ECU related but I'm not sure yet. It may be ECU AND something else, but time will tell...
1. goes from running just fine to acting like I'm rapidly switching the key off/on/off/on/off/on and lighting the CEL while it's in the off state without any warning that it's about to get unhappy. It usually happens the first time on decel but then comes and goes and can also happen while easing into accel and it goes into this off/on/off/on cycle with maybe 1/3 or 1/2 second intervals and yes it's that rapid and the tach falls to either 200-400 at moderate speeds or flat out 0 at low speeds and then jumps back up to normal as the engine is actually cutting out and jumping right back to life in perfect sync with the tach drops and the matching CEL on/off patterns, and it also stalls eventually while trying to continue cruising as it goes in and out of that fubar state and it will definitely stall at low speeds whenever turning while it's in that flaky state, but when I get to a stop in a safe enough location to open the hood and I get a chance to insert the diag jumper it simply flashes "all good", no codes at all like there's nothing wrong whatsoever.
If I turn the key off then try to start the car it does start back up and seems to idle but may or may not go back to doing that or may run normal from that point on...
It's very prone to that on decel, especially after a 5-20 minute cruise down the freeway as I decel down an exit ramp but it WILL sometimes happen while cruising or trying to accelerate too!
I haven't noticed a speed relationship or duration relationship to it yet as I've had it happen while only running around town at 20-35mph one afternoon and I've had it happen while getting off the interstate after 5-10 minutes of freeway speeds.
2. goes crazy rich afr's (exhaust makes your eyes water!) and idles either really high like 1,400rpm's or more or really low like 400rpm's or less, lights the CEL, and loses all resemblance of power in Drive like it's really low on transmission fluid and really doesn't want to move (I could get out, stand up, let someone else get in the car, and easily outrun this car from a stop for a block or two on my feet, I'm not exaggerating, it's THAT BAD!) BUT will "burn out" like a mad-man in Reverse, and the ECU totally ignores the diag jumper being inserted and you can try to reset the ECU and it just remains in that state and refuses to respond to the diag jumper at all...
Then 10-20 minutes later after sitting with the key off it eventually begins responding to the diag jumper, flashes the "all-clear" pattern, and goes back to being normal, if you're lucky... When it does finally begin flashing the "all good" it occasionally stumbles on the flashes (O/D Off stumbles too) like it lost the jumper connection momentarily, but if I check it the next day it behaves fine and the car runs normal for a while.
I tried leaving the jumper in and the key on with the engine off while the CEL was lit and the car was in that undrivable state and eventually the ECU finally acknowledged the jumper being inserted and proceeded to claim everything was fine...
SOOOO.... With the exception of the MkIII Supras' 1JZ-GTE ECU that's prone to shutting the car down randomly for a while and then totally failing as it gets old (due to bad capacitors as I understand it), as unlikely as any other Toyota ECU failure has ever been in my 20+ years of owning Toyota/Lexus vehicles it seems to me that my ECU is actually going bad.
I have not dismantled my dash to see which ECU P/N is in my car now.
You've got a -50140 pictured above,
I've got a -50141 in my hands from the junkyard out of an unknown donor car,
and alldata says there's only a -50142 for the 94 model year.
So how do we determine which one's TRAC, which one's W/O TRAC, and what the 3rd one is for the 94LS?
1994 LS400 89661-50142 (only the one is listed, no mention of TRAC)
1993 LS400 with TRAC 89661-50032
w/o TRAC 89661-50042
They didn't mention TRAC at all for the 1994 model and no mention of the Cali versions at all.
His ECU is a 93 with TRAC so I don't know if my 94 W/O TRAC car is going to like it or not but we'll find out when the usps delivers it to me later this week since he lives 3 hours away from me.
Assuming it's not a bad ECU too, we figure I'll have a lit CEL and trac related diag error codes at all times due to my car's lack of any TRAC components and everything else may be fine otherwise and get me back on the road again, or drivability may be a little wierd if I hit a situation where I get some wheel-spin which the ECU would feel needs the TRAC system, or at the worst that ECU might go into "limp it home" mode if it gets too upset about the missing TRAC components, but we'll see...
I went "yarding" yesterday and out of EIGHT 90-94 LS400's that FIVE of which were 1993 models only ONE still had its' ECU and someone had ripped the dash open to get to it but left it mounted and connected, and for some stupid reason they took the cover off and left it like that with a broken window and it had gotten rained in, damit!
That LS was a 93 with the exact same option packages mine has and was probably one of the ECU models I needed but it was in pieces and wet inside so I didn't even want to try it.
Then I found 2 LS400 ECU's laying loose in the trunk of a 91 with 2 different part numbers and google'd them on my phone while standing at the car in the junkyard.
One P/N search said 91-92 so I left it there. The other said 93 in google but didn't say anything about TRAC or no TRAC and I had no way to tell which 93 it had come out of since it was hidden loose in the trunk of a 91 and of course top top it all off it had yellow junkyard writing on it like it had already been bought and returned but for $30 with a 30 day return option and all the screws still marked with the paint pen to indicate that it probably hasn't been opened up and being the only one that was there and intact I didn't have much choice in the matter.
Oh, and it's a 89661-50141 versus the 50142 alldata part number which leads me to believe it's from a 94 instead of a 93 but I have no clue whether it's for TRAC or no TRAC or possibly a Cali version yet.
My 94 LS400 is apparently a base-model with only the sunroof option. No TRAC or VSC or CD changer or even any seat presets and the tilt is power but the telescopic is manual like the 3rd gen 86.5 - 92 Supras have, and thank god it didn't get the "bag phone" option chewing up the center console bin like EVERY 93 at the yard had but the very cleanly designed and installed steering wheel mounted volume/mute/answer buttons and mic for the bag phone on the left side of the wheel in those cars was pretty cool to see and 'ya gotta love that vintage retro-80's giant cell phone handset with the wired coily cord tucked neatly away on its "cradle" in the center console that was just so cheezy-cool luxury looking for sure!
and I LOVED the actual regular key on/off lock mechanism on the main cell unit in the trunk to prevent unauthorized use of the phone and the phone lock key was still in one of the cars too! The joys of 'yarding...But anyway...
My 94 LS400 appears to have what I believe are two separate issues/problems, both of which I believe and hope are flaky ECU related but I'm not sure yet. It may be ECU AND something else, but time will tell...
1. goes from running just fine to acting like I'm rapidly switching the key off/on/off/on/off/on and lighting the CEL while it's in the off state without any warning that it's about to get unhappy. It usually happens the first time on decel but then comes and goes and can also happen while easing into accel and it goes into this off/on/off/on cycle with maybe 1/3 or 1/2 second intervals and yes it's that rapid and the tach falls to either 200-400 at moderate speeds or flat out 0 at low speeds and then jumps back up to normal as the engine is actually cutting out and jumping right back to life in perfect sync with the tach drops and the matching CEL on/off patterns, and it also stalls eventually while trying to continue cruising as it goes in and out of that fubar state and it will definitely stall at low speeds whenever turning while it's in that flaky state, but when I get to a stop in a safe enough location to open the hood and I get a chance to insert the diag jumper it simply flashes "all good", no codes at all like there's nothing wrong whatsoever.
If I turn the key off then try to start the car it does start back up and seems to idle but may or may not go back to doing that or may run normal from that point on...
It's very prone to that on decel, especially after a 5-20 minute cruise down the freeway as I decel down an exit ramp but it WILL sometimes happen while cruising or trying to accelerate too!
I haven't noticed a speed relationship or duration relationship to it yet as I've had it happen while only running around town at 20-35mph one afternoon and I've had it happen while getting off the interstate after 5-10 minutes of freeway speeds.
2. goes crazy rich afr's (exhaust makes your eyes water!) and idles either really high like 1,400rpm's or more or really low like 400rpm's or less, lights the CEL, and loses all resemblance of power in Drive like it's really low on transmission fluid and really doesn't want to move (I could get out, stand up, let someone else get in the car, and easily outrun this car from a stop for a block or two on my feet, I'm not exaggerating, it's THAT BAD!) BUT will "burn out" like a mad-man in Reverse, and the ECU totally ignores the diag jumper being inserted and you can try to reset the ECU and it just remains in that state and refuses to respond to the diag jumper at all...
Then 10-20 minutes later after sitting with the key off it eventually begins responding to the diag jumper, flashes the "all-clear" pattern, and goes back to being normal, if you're lucky... When it does finally begin flashing the "all good" it occasionally stumbles on the flashes (O/D Off stumbles too) like it lost the jumper connection momentarily, but if I check it the next day it behaves fine and the car runs normal for a while.
I tried leaving the jumper in and the key on with the engine off while the CEL was lit and the car was in that undrivable state and eventually the ECU finally acknowledged the jumper being inserted and proceeded to claim everything was fine...
SOOOO.... With the exception of the MkIII Supras' 1JZ-GTE ECU that's prone to shutting the car down randomly for a while and then totally failing as it gets old (due to bad capacitors as I understand it), as unlikely as any other Toyota ECU failure has ever been in my 20+ years of owning Toyota/Lexus vehicles it seems to me that my ECU is actually going bad.
I have not dismantled my dash to see which ECU P/N is in my car now.
You've got a -50140 pictured above,
I've got a -50141 in my hands from the junkyard out of an unknown donor car,
and alldata says there's only a -50142 for the 94 model year.
So how do we determine which one's TRAC, which one's W/O TRAC, and what the 3rd one is for the 94LS?
02-09-11, 04:51 AM
#6
Pole Position
02-09-11, 09:59 AM
#7
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02-09-11, 11:17 AM
#8
Pole Position
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My 93 came with (had in it when I bought it) 89661-50140 I replaced with one from a '94 89661-50142 both worked fine (was chasing another problem hoping this would fix it). My car is still running the '94 ECU and the '93 is fine and in the basement.
$50 from local yard where I bought my car - non returnable.
$50 from local yard where I bought my car - non returnable.
02-10-11, 03:06 AM
#9
So it turns out that my 94 LS was running on a -50142 but it's obvious that the dash has been opened up before and the actual back cover plate of this -50142 ECU was actually missing and the circuit board was completely exposed so I have no idea if this ECU is original to this car or not (probably not), or what the original ECU P/N would be for this car.
My car is a base-model, no TRAC or any other options besides sunroof.
I installed the -50141 junkyard ECU I bought 2 days ago, stuck the diag jumper in to check for codes and it flashed the "all good" pattern. I started the car, it fired right up, and still flashed the "all good" pattern.
I did a variety of interstate/city driving for about 1/4 tank of fuel today, got no warning lights along the journey anymore, and it still continues to flash the "all good" pattern when I insert the jumper into the diag connector after all that driving.
The car behaves a bit differently now, including transmission shifting a bit more slow/gentle and loosely, and a high 1,200 - 1.400 rpm idle in park or neutral even after it warms up, along with a few other mild inconsistencies, which makes me fairly suspicious of this ECU as well but at least it's drivable now...
My car is a base-model, no TRAC or any other options besides sunroof.
I installed the -50141 junkyard ECU I bought 2 days ago, stuck the diag jumper in to check for codes and it flashed the "all good" pattern. I started the car, it fired right up, and still flashed the "all good" pattern.
I did a variety of interstate/city driving for about 1/4 tank of fuel today, got no warning lights along the journey anymore, and it still continues to flash the "all good" pattern when I insert the jumper into the diag connector after all that driving.
The car behaves a bit differently now, including transmission shifting a bit more slow/gentle and loosely, and a high 1,200 - 1.400 rpm idle in park or neutral even after it warms up, along with a few other mild inconsistencies, which makes me fairly suspicious of this ECU as well but at least it's drivable now...
02-15-11, 09:41 AM
#10
50140, 50141, and 50142 will all work. the 50142 is more deireable as supposedly they fixed some issues. HA!
as for your high idle speed. sounds like the iscv is stuck. take it off the intake manifold and clean it. prolly got carbon buildup on it preventing it from moving.
as for your high idle speed. sounds like the iscv is stuck. take it off the intake manifold and clean it. prolly got carbon buildup on it preventing it from moving.
02-16-11, 02:10 PM
#11
50142
I took off my ecm and the part # was 50142 it been replaced cause a nut was missing. I don't think thats the right ecm my car have heated seat trac and everything else. I brought the car for 1300 put some money into it and have me a nice car. I sent a email to lexus with my vin and imma see if they gon tell me the right ecm number. If unsure should try it
02-17-11, 05:04 AM
#15