Engine & Auto ECU

[jet150]

I was reading a thread in here about converting an auto to a manual and there were some questions raised about if the ECU needed to be changed.

Carsten (aka Gly) posted that the engine ecu and the auto ecu are 2 seperate units.

Can anyone confirm this?

Reason I would like to know is for the people who own autos and wish to install a full stand alone ECU. As we all know it is almost impossible to fit a stand alone ECU to an auto due to the fact that no full ECU's out there can communicate with the auto transmission.
(not sure if a MOTEC can?)

If they are 2 seperate units then surely you can leave the auto unit in and replace the engine unit with an ECU of your choice.

 

[snickells]

Yes Robbie, you have two ECU's in your car

I've got a spare auto one if you need it???

 

[jet150]

Thanks Steve but my car already has one.

This is good to know so when I do my Garrett turbo upgrade I can install a stand alone ECU for the engine and leave in the stock auto ECU to run the transmission.

Or do the 2 units even though they are seperate communicate to one another thus can't be seperated?

 

[Kitty's VR4]

they communicate........

I'm still trying to get a definite answer on whether you'll get error codes becuase A/T ECU cant see the A/T transmission if you do a manual conversion, and what the work round is for this scenario, A few of our members have done conversions, I'm sure they'll jump in here shortly with a learned answer....

 

[bradc]

Converting from an auto to manual is easy, just install the manual gearbox and drive The engine ecu is perfectly fine. There are other problems like the reverse light switch and so on, but if anyone is doing the conversion they'll figure all those small things out.

 

[Guest]

Is it a preface your converting as one of the guys in the UK has had problems with the TCL kicking in when he did his conversion. Also Caveman on CVR4 had an Autronic ecu fitted as Brad has and they are supposed to have manged to get the 2 ecu's working together

 

[jet150]

No, im not doing a conversion to a manual I want to install a full stand alone ECU with the auto.

My problem is that most aftermarket ECU's won't communicate with the auto.

A tuner I know said that they can install an aftermarket ECU but leave the original one in the car to. They will cut the engine management wires that control air/fuel & ignition and join them to the aftermarket ECU, and let the original ecu control the auto and other things like cold start.

The dudes at Microtech said this can be done but im willing to listen if anyone on here thinks it won't.

 

[Madhav]

No, im not doing a conversion to a manual I want to install a full stand alone ECU with the auto.

My problem is that most aftermarket ECU's won't communicate with the auto.

A tuner I know said that they can install an aftermarket ECU but leave the original one in the car to. They will cut the engine management wires that control air/fuel & ignition and join them to the aftermarket ECU, and let the original ecu control the auto and other things like cold start.

The dudes at Microtech said this can be done but im willing to listen if anyone on here thinks it won't.

I came up across this exact problem, communication issues, even though my old mechanic assured me it would be ok and I handed over the money for the ECU in good faith... in the end it actually destroyed my perfectly good Auto gearbox...

So yeah I can assure you it doesn't work on a series 1 leggie with the haltech E11v2, my new mechanic has spent literally countless hours trying every possible way around it, he even had a specialist come and assist him, a dude that installs them aftermarket ECU's everyday for a living... And believe me when I say I would love to be proven wrong... please prove me wrong!!!

Make sure if they try to convince you it is possible that you get a written quote, and that this should cover all possible complications and extra time needed and also any damage that may arise from these complications.

 

[jet150]

The tuner is speaking with the guys at Microtech and they think they can install an ecu by leaving the original in the car and having their unit only controlling air/fuel & ignition.

Did your mechanic try that Madhave?

This problem is pissing me off! lol.

 

[Madhav]

The tuner is speaking with the guys at Microtech and they think they can install an ecu by leaving the original in the car and having their unit only controlling air/fuel & ignition.

Did your mechanic try that Madhave?

This problem is pissing me off! lol.

Yeah like I said, EVERY possible combination. I had the E11 only controlling a very limited range of functions, the rest were being done with the factory ECU and auto trans ECU.

 

[montgomery]

your ecu is prob only controlling fuel/ign/spark/boost , all the basic things.

 

[bradc]

Someone in the UK managed to get an Autronic SM4 working with the stock auto and engine ecus still in the car controlling the auto box.

My tuner gave up and my car became a manual when he was installing my SM4, he could get it to select 1st and 2nd in tiptronic mode, but nothing else.

 

[Guest]

Someone in the UK managed to get an Autronic SM4 working with the stock auto and engine ecus still in the car controlling the auto box.

My tuner gave up and my car became a manual when he was installing my SM4, he could get it to select 1st and 2nd in tiptronic mode, but nothing else.

I posted the info about Caveman and the Autronic earlier Brad though he has now sold the VR4

 

[Madhav]

Someone in the UK managed to get an Autronic SM4 working with the stock auto and engine ecus still in the car controlling the auto box.

My tuner gave up and my car became a manual when he was installing my SM4, he could get it to select 1st and 2nd in tiptronic mode, but nothing else.

My car is becoming a manual, got the clutch and flywheel on the way, just keep hitting walls with sourcing a reasonably priced manual conversion kit.