1UZ with factory ECU into BMW e30

[black_LS]

Hi all,

I'm currently gathering parts for my swap, and had a question. I've been researching 1UZ swaps for that last couple of weeks, specifically e30 swaps. Most everyone has used a standalone engine management system. Why is that? I'm planning on using the original 1UZ ECU (non-vvti). Is that possible?

If it comes to using a standalone ECU, I will most likely scrap the project, as that would shoot it out of budget, and I don't want to deal with tuning.

Your input is greatly appreciated.

Thanks

 

[gloverman]

Factory ECUs work fine if you wire them correctly. I wire around 50-60 stock ecus a year with about 20-25 aftermarket ECUs on 1uzs. It may take some work to get the rest of the car functioning correctly. Cheers

 

[65gtmustang]

I built an E36 coupe with a 1uz and ran the stock ecu.Only required minor work to make all dash functions work okay and there have been plenty of E30's done over here and i would imagine the bmw ecu doesn't integrate into the car electronics at all just like the E36.

 

[George_R]

There's no major problems with non-vvti 1UZ factory ECU's, unless late non-JDM models which may have built in security functions.

Other than that, there's a rumor factory timing maps are somewhat retarded in low rpm range
I would go for vvti engine unless you plan to run some sort of boost later on

 

[black_LS]

Factory ECUs work fine if you wire them correctly. I wire around 50-60 stock ecus a year with about 20-25 aftermarket ECUs on 1uzs. It may take some work to get the rest of the car functioning correctly. Cheers

I built an E36 coupe with a 1uz and ran the stock ecu.Only required minor work to make all dash functions work okay and there have been plenty of E30's done over here and i would imagine the bmw ecu doesn't integrate into the car electronics at all just like the E36.

Thanks for your replies. I just spent quite a few hours reading Lexus and BMW wiring diagrams. The ECU is more or less separate from body functions. I think I've figured out how to go about it.

Some potential issues:

• In terms of A/C, the first gen LS has 2 pins on the engine ECU, AC and ACMG:
  • AC is connected to the MGC pin on the A/C ECU, which comes from the A/C button. From what I understand, AC is a constant 4-6V (10-14V for 1995) until it is grounded out by the MGC pin, at which point it triggers the next pin:
  • ACMG gives an output to magnetic clutch relay, which turns the magnetic clutch (compressor) on 0.5 seconds after the button is pushed so the ECU can raise the RPM - I think this gives ground to the relay, but I can't be sure.
  • The 1995 has an additional THWO pin that deals with A/C, but I'm not sure what it does.
  
  There is also a connector with 2 wires on the compressor itself which is used for the compressor lock sensor. I'm assuming I don't need this.
  
  So, I'm thinking if I can ground AC when the button is pushed on the dash, and send ACMG to the compressor through a relay, it might work. I'm wondering if the Lexus compressor will integrate with the rest of the BMW system.

• Another issue is the oil level and temperature gauge sensors. I'm wondering if the BMW cluster will accept the Lexus sensor readings.

There's no major problems with non-vvti 1UZ factory ECU's, unless late non-JDM models which may have built in security functions.

Other than that, there's a rumor factory timing maps are somewhat retarded in low rpm range
I would go for vvti engine unless you plan to run some sort of boost later on

All vvti ECUs have immobilizers here. I can potentially source a JDM ECU; I heard they lack the immobilizer and EGR system. Will a JDM ECU work with a USDM/Canadian engine? Another issue is the absence of transmission sensors throwing check engine codes.

 

[George_R]

All vvti ECUs have immobilizers here. I can potentially source a JDM ECU; I heard they lack the immobilizer and EGR system. Will a JDM ECU work with a USDM/Canadian engine? Another issue is the absence of transmission sensors throwing check engine codes.

you need UZS15x series ECU, it has no immo, and it's pin compatible with LS400. Or the security can be disabled on any LS400

didn't understand the other part of your message. UZS155 runs the same sensor on its transmission as any other LS400 or Celsior. You can display 2-digit flash codes on the warning light, or run a scanner for dirt cheap with any factory 1UZ-VVTI engine control computer

 

[Zuffen]

Just swap the BMW oil pressure sensor in place of the UZ one.

The oil level switch is a simple float switch that operates a micro switch, so it's either on or off.

 

[black_LS]

you need UZS15x series ECU, it has no immo, and it's pin compatible with LS400. Or the security can be disabled on any LS400

didn't understand the other part of your message. UZS155 runs the same sensor on its transmission as any other LS400 or Celsior. You can display 2-digit flash codes on the warning light, or run a scanner for dirt cheap with any factory 1UZ-VVTI engine control computer

I plan on disconnecting the automatic transmission and running a manual. I read that it's difficult to get the VVTi LS400 ECU to behave when doing that (it throws codes because of the speed sensor in the transmission, limp mode, etc.). I'm not sure if this is because of the newer VVTi 1UZ or because of OBD2.

Looks like UZS15x is a Crown Majesta. Is that the one that has the engine ECU separate from the transmission ECU?

Just swap the BMW oil pressure sensor in place of the UZ one.

The oil level switch is a simple float switch that operates a micro switch, so it's either on or off.

Thanks for the tip.

 

[George_R]

There're ways to stop vvti ecu from throwing a/t related obd codes, when there's no a/t . However non-vvti ecu would normally throw these codes as well.

I haven't seen a single 1uz with separate engine/ect computers . Maybe that's because I don't buy old crap to save a couple cents. All 1992+ toyotas have single computer.

 

[black_LS]

There're ways to stop vvti ecu from throwing a/t related obd codes, when there's no a/t . However non-vvti ecu would normally throw these codes as well.

I haven't seen a single 1uz with separate engine/ect computers . Maybe that's because I don't buy old crap to save a couple cents. All 1992+ toyotas have single computer.

Any info on stopping the a/t codes?

What are the differences in wiring an OBD2 motor vs. an OBD1 with a manual swap? All of the 96+ LS400s here are OBD2. Are there many differences between wiring a 96-97 and 98-00?

Thanks

 

[George_R]

I regard all no-vvti 1UZ's as OBD1 because I only deal with JDM parts. Non-vvti's are only a tad easier to wire properly in my opinion.

As for a/t related obd2 codes, here's a little hint. In properly wired vehicle with 1uz and its factory a/t, you may disconnect all solenoids and speed sensors, then start the engine. There will be no obd2 codes until you actually drive.

 

[black_LS]

I found a source for JDM import 1uz vvti motors. Did all Japanese market LS400/Celsior vvti 1uzs come without the immobilizer, or did I understand that wrong?

I'm hoping to get the ECU together with the motor and not have to deal with the security issues.

 

[black_LS]

If still immobilized, would it be possible to place the key sensor+transponder in the glove box and forget about it (use donor car's key and ignition)?

 

[George_R]

vvti ICF20's are all immobilized
You can however source native key from donor and any compatible antenna amplifier and be happy
Or, you may look for someone who offers immo bypassing. Me and a couple guys here can perform such a work.

 

[black_LS]

Interesting. So if I have the key and antenna, can I store them out of sight with the ECU and continue to use the original cars key/ignition system?

 

[George_R]

of course. The only things that matters regarding the key is a tiny transponder inside of it. As long as immo system detects the transponder it's locked on to, you can start your engine by shortening the appropriate wires anyway you like