1UZ ECU - How specific are they to each engine/model - LS400/Celsior

**roadkill** · 24-09-2012, 11:44 AM

hi,

yeah i wondered how the fan control worked between the hydraulic fan and the electric fan.....

So, the only ECU i've managed to find so far for a 93/94 was a cali spec ls400. Finally got it last night but it wouldn't even start the car (not really surprised, more frustrated still) but didn't have any time to diagnose. So i'll do the usual spark timing fuel check today. To me it sounded like it wasn't getting fuel so maybe the cali setup was a little different.

I've got my eye on one in NZ, so i'll probably buy that as well. Money money money, must be funny,.......

bEn

**CrUZida** · 24-09-2012, 04:39 PM

I didn't think any had electric and hydraulic?

The Celsior has hydraulic and no electric, where as the LS400 has electric for the aircon, and viscous for radiator cooling.

**nathanshnoz** · 26-09-2012, 10:57 PM

Originally Posted by roadkill

Hi All,
Now, so far i haven't been able to find anyone with the same part numbered ECU. I have an 89661-50180.
bEn

i have the same model ECU - but i need it so you can't have it.....sorry! good luck with sorting out this annoying problem!

**roadkill** · 27-09-2012, 07:27 AM

yeah, i mean that there is probably something different in the ecu to control the electric fan vs controlling the hydro fan.

Originally Posted by CrUZida

I didn't think any had electric and hydraulic?

The Celsior has hydraulic and no electric, where as the LS400 has electric for the aircon, and viscous for radiator cooling.

**slipway NZ** · 27-09-2012, 08:41 PM

Had the same problem with my LS, was the ecu. Im 100% sure it wil be your problem. In NZ we will have a ecu for you

**roadkill** · 11-10-2012, 10:39 AM

Hi,

so I fiiiiiiiiiiiiiiiiiiinally managed to get an ECU for this. It's actually a celsior ECU, not an LS400 (different part no) but it works! Hurrah! I haven't driven it yet but i can floor board the engine and it red lines, doesn't cough splutter or anything. Just runs as it should! Would love to know what the difference actually is between the two. I've still gotta take the sump off of the auto, re-seal and fill it back up before i take it for a spurt.

So, anybody want a somewhat stuffed LS400 ECU?

bEn

**4th surf** · 11-10-2012, 11:02 PM

I think that I know which Celsior ECU that you have got. Late UCF11 which as you've found has better fuel and ignition maps. Pinouts are pretty much the same and these ones did have another ECU for the hydrofan so you shouldn't have any probs with code 56. Just remember to run it on 95 octane fuel or better

**Herus** · 14-10-2012, 07:18 PM

Whats the part number on this new ECU?

Herus

**roadkill** · 14-10-2012, 11:42 PM

Hi,

the old ecu for the ls400 was 89661-50180 and i replaced it with a 89661-50170. I can confirm too that the US spec ls400 ecu does not work. Doesn't even start the friggin car.....

bEn

**dumbass** · 15-10-2012, 08:57 PM

doesnt the us spec motor have the igntiion outputs of somehting swapped over
i know this is the case with 95 or 96 or 97 ls400 ecus

**roadkill** · 16-10-2012, 08:25 AM

nfi man. When i got it i just plugged it in and crossed my fingers. It would crank but not even a hint of it starting. I had a look into the pinouts of it all and there were a few that were different so hence didn't go any further with it. Since then it's friggin disappeared. Have no idea what i did with it.....

bEn