Hi all, first post. I bought an LS400 1994 UCF10 a couple months ago, have completely rebuilt the engine. Original issues were typical ECU issues such as not going above 2k revs. After rebuilding the entire engine because the previous owner decided a radiator is an opinion, coating in Cerakote and Piston coat because why not, and replacing the capacitors on the ECU, we plugged everything in, and found that we're getting a code 47, which according to Lexls is "47 - Sub-throttle position sensor signal". Along with that, the left side cylinders seem to be getting far higher fuel pressure than right side, and the cat is spitting pure flame compared to right. No mufflers and only cats for testing means we can hear a lot of the issues that we previously didn't think were there. Probably the fuel pressure regulator; in the process of checking pressure today.

Regardless, my inquiry is about the ECU. I don't HAVE a sub throttle. The car is non-trac variant, and only has the main Throttle Position Sensor. I've been doing some digging around and found there seems to be seperate ECU's for trac and non-trac variants, and the ECU has been replaced 2006, meaning the seller I got the car from does not have the original ECU. My ECU model number is 89661-50160 and according to this post seems to be from a 1993 variant.
From what the Colin said the difference between trac and non-trac is the ending of 60 and 50. Would that still apply for my ECU's 160? If so, what would the correct model numbers be for the 1994 UCF10 non-trac ECU be?

Thank you very much, I appreciate all the help.

 

This thread discusses the 60 and 70 variant:
https://www.clublexus.com/forums/ls-...1-50160-a.html

 

It gets A LOT more complicated than that. Trac vs non-track, California, USA, Canada, Taiwan... and then the years and months... Thankfully, I found this list of ECU P/N on my computer. It should be accurate if incomplete as I don't see RHD P/N here, nor the 50224, which judging by this list is for early 2nd gen. (and I just realized there is a gap from Jan 1994 until Oct 1994 for California spec, but not for the rest of US):

90-93 model
Part Number, Production Date, Model(Description)
89661-50010, 05/1989-08/1990
89661-50020, 05/1989-08/1990 W(TRACTION CONTROL)
89661-50030, 05/1989-08/1990 CALIFORNIA SPEC
89661-50031, 08/1990-09/1990
89661-50032, 09/1990-08/1992
89661-50040, 05/1989-08/1990 CALIFORNIA SPEC & W(TRACTION CONTROL)
89661-50041, 08/1990-09/1990 W(TRACTION CONTROL)
89661-50042, 09/1990-08/1992 W(TRACTION CONTROL)
89661-50140, 08/1992-01/1993
89661-50141, 01/1993-08/1993
89661-50142, 08/1993-10/1994
89661-50150, 08/1992-01/1993 CALIFORNIA SPEC
89661-50151, 01/1993-01/1994 CALIFORNIA SPEC
------------------------------------------------
94-97 Model
89661-50220, 10/1994-02/1995
89661-50221, 02/1995-08/1995
89661-50230, 10/1994-02/1995 CALIFORNIA SPEC
89661-50231, 02/1995-08/1995 CALIFORNIA SPEC
89661-50290, 10/1994-02/1995 USA TAIWAN SPEC
89661-50291, 02/1995-08/1995 USA TAIWAN SPEC
89661-50302, 08/1995-09/1995
89661-50303, 09/1995-08/1996
89661-50330, 08/1995-08/1996 USA TAIWAN SPEC
89661-50340, 08/1996-09/1996
89661-50341, 09/1996-07/1997
89661-50370, 08/1996-11/1996 USA TAIWAN SPEC
89661-50371, 11/1996-07/1997 USA TAIWAN SPEC
------------------------------------------------
Model after 98
89661-50430, 07/1997-10/1997
89661-50431, 10/1997-11/1997
89661-50433, 11/1997-02/1998
89661-50434, 02/1998-08/1998
89661-50480, 07/1997-10/1997 USA TAIWAN SPEC
89661-50481, 10/1997-11/1997 USA TAIWAN SPEC
89661-50483, 11/1997-02/1998 USA TAIWAN SPEC
89661-50484, 02/1998-08/1998 USA TAIWAN SPEC
89661-50501, 08/1998-05/1999
89661-50502, 05/1999-08/1999
89661-50511, 08/1998-05/1999 USA TAIWAN SPEC
89661-50512, 05/1999-08/1999 USA TAIWAN SPEC
89661-50530, 08/1999-11/1999
89661-50531, 11/1999-08/2000
89661-50540, 08/1999-08/2000 USA TAIWAN SPEC

 

That whole scenario with a CA spec cars was