E36 ECU EPROM swap

[LCP]

I got hold of a used Hiop chip for my M50B25TU 325i(M)... decided to put in the chip myself, so here goes the steps, plus photos...1) Disconnect the -ve lead of the battery

2) Remove the two round clips holding the foam rubber insulation, and remove the foam rubber piece

3) Remove the fusebox cover, and unplug the rearmost relay for easier access. Remove the ECU compartment cover, held by five size 8 bolts.

4) Two shots of the ECU, gently unclip the cable loom from the cover

5) Remove the ECU gently from the compartment, and finally undo the connector locking clip and remove the connector from the ECU.

6a) Open up the ECU by undoing the clips (which are actually part of the aluminium cover). The EPROM chip is the one with the plastic cover on top of it. The chip is sitting on an IC socket.

6b) Macro shot of the stock EPROM chip. It's a Texas Instrument chip, with customised markings, but I believe this is a 20nanosecond 27C512 EPROM.

6c) Macro shot of the Hiop chip. This chip is meant for stock M50B25TU.

6d) The Hiop EPROM in place, taking care to put the pin 1 location (notch on the chip) the same way as the stock chip, else there will be some holy smoke...

6e) and 6f) View of ECU PCB after the EPROM swaphttp://i76.photobucket.com/albums/j37/cplim/E36EPROMswap/Step6e.jpghttp://i76.photobucket.com/albums/j37/cplim/E36EPROMswap/Step6f.jpgRefittting is the reverse of the above procedure.Improvement is noted for mid and high rpm, especially more from 4000rpm onwards, car pulls much harder from that point, all the way till the redline.LCP

 

[E28driver]

Great pics!

How did you know that the chip was for a 413 ECU? I believe that there were quite a few ECU #s for M50, 402, 405 etc.

 

[Lee36328]

I still have not decided whether this is one of the Best DIY Thread Of The Year, or one of the Worst Racun Thread Of The Year....

Either way, it's great.

Now, very itchy, looking for a chip...

 

[ALBundy]

Originally posted by E28driver@May 15 2006, 06:21 AM
Great pics!

How did you know that the chip was for a 413 ECU? I believe that there were quite a few ECU #s for M50, 402, 405 etc.

402 and 405 is non vanos ECU if I remember correctly. This chip is for the M50TU.

 

[LCP]

Yes, this chip is meant for the M50B25TU single Vanos, for both E34 and E36...

Anyway, don't worry, I ain't no big racun... But on the other hand, the improvement is really felt, now can do 0-100 as fast as a.... stock Proton Putra! But I have to exercise restraint, my car and engine is 11.5 years old, hafta be a bit careful about revving till kingdom comes...

LCP

 

[Lionel_Koh]

Great job.........

BTW how much the chip cost?

 

[Fireblade]

Good pics LCP. Just curious to find out from you guys - after re-chipping the ECU would Modic/Gt1/Gt2 be able to diagnose all the functions/faults as per original chip?

 

[ALBundy]

Yup, it shouldnt be a problem for the various BMW diagnostic machines to read it.

However if the mechanic is using Launch Diagnostic machine, he may not be able to.

 

[LCP]

Lionel, this is just a one-off sale from someone I know. New is in the region of RM1.5k-2k I think. But if you are going to USA or you know someone going to USA, get the equivalent chip there, cheaper... Dinan, etc, many other brands are available.

LCP

 

[LCP]

Guys, can anybody with computer and electronics background confirm that this EPROM is the 512kbit (64kbyte) 27C512 chip? The stock chip has customised markings, I can't decipher it (shame on me, working in the chip industry), but I do know that this is a 20nanosec chip. Some websites do say the chip is a 27C512.

LCP

 

[weechoon]

LCP,
so...what is the horsepower of your car now ?

 

[dee136]

Originally posted by LCP@May 16 2006, 09:24 AM
Guys, can anybody with computer and electronics background confirm that this EPROM is the 512kbit (64kbyte) 27C512 chip? The stock chip has customised markings, I can't decipher it (shame on me, working in the chip industry), but I do know that this is a 20nanosec chip. Some websites do say the chip is a 27C512.

LCP

Yes bro, it is CMOS 512k(64kx8), 20ns UV EPROM.
I could be wrong then.

 

[LCP]

weechoon,

No dyno available here up north, just relying on my good ol' butt dyno... But then human butts are only good at detecting differences in torque, and lousy when it comes to detecting absolute torque. And definitely useless when it comes to detecting absolute power.

Okay, here's what I felt... I think the improvement in max power is about 5-10hp only, best case 10-15hp. The most important aspect is not the absolute max horsepower, it's how the chip gets you there (max power). On the whole the engine is more revvy, especially from mid range rpm onwards, and it really pulls much harder from 4000rpm onwards. In other words, improvement in mid and high rpm torque is the biggest item here, giving rise to better driveability.

LCP

 

[masCh]

It is a TI chip, the logo gives it away
But to determine what chip it is, would be harder

Is there any designation UNDER the chip to say its 27C512 EPROM?

 

[jarance]

getting the chip is one thing. To be able to write the "program" into
the new eeprom is another thing all together.

It just you are buying a computer without the operating system.

pss..st.. cloneing the chip is illegal and infringed copyright..

 

[jsen]

LCP,

how about fuel consumption.. any improvements on tat part?

do we need any resetting done..?

 

[LCP]

jsen, no difference in fuel consumption... when the chip is plugged in, the battery is already disconnected so the ECU can be taken out, that already reset the ECU

 

[jsen]

thks man for the info.. great DIY..

did u solder yrself or how?...

 

[LCP]

No need to solder, the original EPROM chip is already on a socket, just a plug and play literally.

 

[jsen]

alrite thks man for the info n great pics..

cheers.