earossi

I am investigating the purchase of a new ECU for my 98 993. Porsche is now "remanufacturing" ECU's for the 993. Very pricey, but they are the only game in town. I can purchase one through Sunset for around $2000 plus a core charge of about $1800. My understanding is that Porsche reuses the ECU case but adds all new internals.

My question is about commissioning the new ECU. Is this a DIY or do I have to get a dealership involved. Hopefully it is plug and play. Also, what needs to be done to my car since the current ECU had had the immobilizer decommissioned?

JM993

Plug and play. You will probably need to deal with the immobilizer (re-install it) or have your new ECU modified.

Basal Skull

I have had 6 different ecu's in my turbo and have never had to mess with the immoboilizer

hoggel

Wow. I bought one from Sunset a few years ago for ~$1000 outright. I had a different experience than plug and play. I was told the software had to be installed using the PWIS. The VIN is entered and the PIWIS downloads the correct program for the car. I had some peculiarities that the two local dealers could not deal with so I sent mine to Steve Weiner for programming.

JM993

That's strange. Unlike later Porsches and other German cars, the ECU, immobilizer and key are not linked. You can substitute replacements for any of the above without programming. Like Basal, I've swapped ECUs back and forth with no issue.

hoggel

That may work with used ECUs. It is my understanding that new ones do not have software loaded.

nine9six

Hmm, that's interesting...So the $2k only buys the module, then you have to pay a dealer to flash the chip? What a pita, along with a gouging to boot!

Hilltopper

Buy new with chip and immobilizer programed out from Steve W. Power increase for real and will now work like a normal car re: lock button on fob. May be one of the best of many investments I have made on my 993.
Plug and play!

TheBen

+1 on Steve Weiner

golfnutintib

may i ask perhaps a naive question -- why in the normal course of owning/driving a 993 would a new ecu purchase be necessary?

...and how is this materially different that re-flashing an ecu with an aftermarket tune like many shops do... protomotive, steve wong, etc etc...

earossi

I've had the original ECU worked on numerous times due to a stalling issue. We now believe the unit is malfunctioning and the solution is to replace it.

Hilltopper

Thread started with assumption new ECU needed and if it is 1995/1996, will need new. Especially if going with LW RS clutch. Search the forum. Mine from Steve is a new, not rebuilt 1998 ECU with chip and immobilizer delete and worth every penny. I owe Steve!

hoggel

I bought a new ECU after I swapped the transmission from tiptronic to manual in my car. After the swap, with the manual trans and the tiptronic ECU, the car had a CEL with a fault for transmission status. The car would stall every time I engaged the clutch. The tiptronic deceleration and idle maps were wrong for the manual trans. I looked in the PET and saw that the manual trans ECU had a different part number. So I bought a new one. It came with a some kind of tag that said it had to be initialized by an authorized Porsche service center. I called my local dealers and they both said that software needed to be loaded into it with the PIWIS. They both told me that they had to enter the VIN to get the software and that it would be tiptronic software for my car. One told me they could use a VIN from another 97 with manual transmission but then both cars would be flagged in the Porsche database as having replacement ECUs. I called Steve Weiner and he said he could take care of it. He included some other options that I appreciate. Yes, I bought a new ECU for a bit more than $1k and paid Steve ~$1k to program it. Money well spent at that point. Steve saved my project! In retrospect, he probably could have reprogrammed the tiptronic ECU for me. But I bought the new one before I talked to him.

For all of the years I had the car before the transmission swap I had problems getting the car to pass emissions. It would intermittently reset the readiness flags. A couple times I would have them all set, pull into the test station, and when the tech would pull it in and hook it up they would be reset. Most years I would have to do the drive cycle multiple times. I tried all the troubleshooting I could think of, looked for intermittent power and grounds , ... . After replacing the ECU for the project described above I have had no problem with the readiness codes. Must have been an intermittent connection inside the ECU.

I posted most of this before. Some one IM'd me and asked if they could buy the used tiptronic ECU. I told them that I thought it had issues with the readiness codes. He said that his shop told him that would not be a problem for his race car
application. And they said that they would load different software so it didn't matter that it was tiptronic.

For whatever that's worth.

golfnutintib

After I put in an RS camshaft into my 993 C2S along with a top end rebuild I also had an idle/stalling problem. Messing with the gross control on the ISV did not solve it. So we sent the ECU to Protomotive and they raised the idle setting by 150 rpm... so this aspect you mention I do understand...but in my case I solved it with a remap of the existing ECU...my car is a 97...

Steve W certainly the man... I am picking up a 95 soon, so maybe this is a bridge I will soon need to cross...

Major tranny swap out like this case, of course, I get that a new ECU, freshly written on, may make the most sense.

Thanks all for educating me.

earossi

I had a long chat with Steve Weiner last night about my thoughts to purchase a new ECU for my car. We discussed if a new ECU from Porsche was plug and play or not. Steve said that the new ECU would be plug and play UNLESS I wanted the immobilizer activated which has to be done through the dealer since it is VIN dependent. Since I don't want the immobilizer, I should be able to install a new unit right out of the box. Obviously, the new ECU would have to go through an adaptation before the car sorts itself out.