HELP! Swapped motors from is300 to gs300 ECU problem/question
08-21-11, 06:15 AM
#1
Driver School Candidate
Thread Starter
Join Date: Aug 2011
Posts: 4
Likes: 0
Received 0 Likes
on
0 Posts
HELP! Swapped motors from is300 to gs300 ECU problem/question
HELP!
So, I recently had my '00 GS300 stock engine seize up on me. I found an 04'
IS 300 engine with only 50,000 miles on it. I have already swapped out
engines. Upon putting the new engine in, I noticed that not all the plugs go
into the "gs300" ecu. I then went to the IS 300 seller and requested their
ECU. I put the new ECU and noticed that all the engine wires plug in, but not all
the GS300 body wires do not.
My question, would I be better off with the new ECU or old one? I'm trying to figure out what else would need to be done without the hassle of rewiring.
I did try the search function, however, I can't find a clear cut answer. Any help would be appreciated!!
-Rhett
So, I recently had my '00 GS300 stock engine seize up on me. I found an 04'
IS 300 engine with only 50,000 miles on it. I have already swapped out
engines. Upon putting the new engine in, I noticed that not all the plugs go
into the "gs300" ecu. I then went to the IS 300 seller and requested their
ECU. I put the new ECU and noticed that all the engine wires plug in, but not all
the GS300 body wires do not.
My question, would I be better off with the new ECU or old one? I'm trying to figure out what else would need to be done without the hassle of rewiring.
I did try the search function, however, I can't find a clear cut answer. Any help would be appreciated!!
-Rhett
08-21-11, 07:39 AM
#2
Lexus Test Driver
iTrader: (14)
Join Date: Jan 2003
Location: Charleston,SC
Posts: 855
Likes: 0
Received 0 Likes
on
0 Posts
well first of all you would be better off posting this question in the correct section....
However im not sure why you are doing extra work for nothing switching ECU's and trying to plug in other wiring harnesses, of course they are going to be different they are completely different cars...
you SHOULD have taken the OLD GS wiring harness off the OLD GS engine when you removed it and put it on the NEW IS engine when you installed it, you may have had to change a few sensors for the plugs at most and never touched the ECU.
However im not sure why you are doing extra work for nothing switching ECU's and trying to plug in other wiring harnesses, of course they are going to be different they are completely different cars...
you SHOULD have taken the OLD GS wiring harness off the OLD GS engine when you removed it and put it on the NEW IS engine when you installed it, you may have had to change a few sensors for the plugs at most and never touched the ECU.
08-21-11, 10:30 AM
#4
Driver School Candidate
Thread Starter
Join Date: Aug 2011
Posts: 4
Likes: 0
Received 0 Likes
on
0 Posts
well first of all you would be better off posting this question in the correct section....
However im not sure why you are doing extra work for nothing switching ECU's and trying to plug in other wiring harnesses, of course they are going to be different they are completely different cars...
you SHOULD have taken the OLD GS wiring harness off the OLD GS engine when you removed it and put it on the NEW IS engine when you installed it, you may have had to change a few sensors for the plugs at most and never touched the ECU.
However im not sure why you are doing extra work for nothing switching ECU's and trying to plug in other wiring harnesses, of course they are going to be different they are completely different cars...
you SHOULD have taken the OLD GS wiring harness off the OLD GS engine when you removed it and put it on the NEW IS engine when you installed it, you may have had to change a few sensors for the plugs at most and never touched the ECU.
08-21-11, 10:35 AM
#5
Driver School Candidate
Thread Starter
Join Date: Aug 2011
Posts: 4
Likes: 0
Received 0 Likes
on
0 Posts
I wish I would have done more research before I started.
08-21-11, 11:53 AM
#7
Lexus Test Driver
iTrader: (14)
Join Date: Jan 2003
Location: Charleston,SC
Posts: 855
Likes: 0
Received 0 Likes
on
0 Posts
Sounds more like someone didnt know what they were doing and started hacking things up, better go buy you a soldering iron and get to fixing it.
Seriously man??? you bought an engine from a COMPLETELY different car and you expect the wiring and ecu to plug and play perfectly??? 
If you didnt want to do any extra work you should have bought the correct engine for your car instead of buying a different one.
Both jeff and i have told you what you need to do already... DITCH THE IS300 ECU AND WIRING HARNESS IT WONT WORK!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Is that clear enough????
either fix your GS harness or get another one and stop trying to be cheap and rigging stuff up.
If you didnt want to do any extra work you should have bought the correct engine for your car instead of buying a different one.
Both jeff and i have told you what you need to do already... DITCH THE IS300 ECU AND WIRING HARNESS IT WONT WORK!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Is that clear enough????
either fix your GS harness or get another one and stop trying to be cheap and rigging stuff up.
Last edited by IOWNALEXUS; 08-21-11 at 11:57 AM.
Trending Topics
08-21-11, 04:25 PM
#8
Driver School Candidate
Thread Starter
Join Date: Aug 2011
Posts: 4
Likes: 0
Received 0 Likes
on
0 Posts
Sounds more like someone didnt know what they were doing and started hacking things up, better go buy you a soldering iron and get to fixing it.
Seriously man??? you bought an engine from a COMPLETELY different car and you expect the wiring and ecu to plug and play perfectly???
If you didnt want to do any extra work you should have bought the correct engine for your car instead of buying a different one.
Both jeff and i have told you what you need to do already... DITCH THE IS300 ECU AND WIRING HARNESS IT WONT WORK!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Is that clear enough????
either fix your GS harness or get another one and stop trying to be cheap and rigging stuff up.
Seriously man??? you bought an engine from a COMPLETELY different car and you expect the wiring and ecu to plug and play perfectly???
If you didnt want to do any extra work you should have bought the correct engine for your car instead of buying a different one.
Both jeff and i have told you what you need to do already... DITCH THE IS300 ECU AND WIRING HARNESS IT WONT WORK!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Is that clear enough????
either fix your GS harness or get another one and stop trying to be cheap and rigging stuff up.
I was told by three different people that it was a perfect fit. That to me means aligning up with the wiring. I am going to put the GS harness on and use the GS ECU. Anything else I should expect?
Sorry, I'm new engine swapping, didn't know what to think.
Thanks for the advice though.
08-21-11, 05:00 PM
#12
Driver School Candidate
Join Date: Aug 2011
Location: AL
Posts: 32
Likes: 0
Received 0 Likes
on
0 Posts
I don't...just surprised is all...I am a mod on 2 other forums, I was just wondering is this is the type of responses I should expect...thanks for clearing it up. Back on topic...
08-21-11, 05:19 PM
#13
Asking in the first gen IS or the second gen GS forums would've made a lot more sense... he just got lucky to have a few folks who know 2JZ wiring also be in this forum (which is for cars that use several totally unrelated engines to either of the ones involved in his situation)
Last edited by Kurtz; 08-22-11 at 07:57 AM. Reason: Pronoun correction
12-31-11, 12:44 PM
#15
Driver School Candidate
Join Date: Aug 2011
Location: FL
Posts: 9
Likes: 0
Received 0 Likes
on
0 Posts
im a little late here but...
is300 harness works on a gs300.
the problem i see here is that the IS harness and ecu that was used was from an 04 and the gs is a 00.
for the IS harness to work on a 98-00 gs the IS harness would have to be from an 01.
thats why you can do aristo(GS300) swap to an IS300 without any issues with electical stuff, its the same crap from either platform, just gotta make sure the years are compatible.
IS300/2001 ok with gs300/1998-2000
IS300/2002-up ok with gs300/2001-up
is300 harness works on a gs300.
the problem i see here is that the IS harness and ecu that was used was from an 04 and the gs is a 00.
for the IS harness to work on a 98-00 gs the IS harness would have to be from an 01.
thats why you can do aristo(GS300) swap to an IS300 without any issues with electical stuff, its the same crap from either platform, just gotta make sure the years are compatible.
IS300/2001 ok with gs300/1998-2000
IS300/2002-up ok with gs300/2001-up