Help with 986 ECU Repair
#1
Help with 986 ECU Repair
Hello Everyone,
This is my first post on this forum and I am surely in need of your expertise I am going to attempt fixing my 1999 boxster dme. The car has had a variocam problem ever since I bought it few months back. After replacing the solenoid I traced the problem to the ECU. I called around and got a quote of $650 to solve this problem. I decided to try and fix this myself first since for that much money I could find a used ECU and have the dealer program it for me. So I am not too worried about ruining this one. Once I got inside the ecu I found a burnt Bosch transistor with the following #30046 44108.1 9908 written on it. I've tried locating a replacement, but without much success. Any ideas where to find one or any suggestions for a different brand replacement? Btw, I have ordered a couple of IRFZ44's which are on their way. I also found these Bosch BIP373 on http://www.diyautotune.com/catalog/b...kit-p-230.html Would any one of those work as a replacement? I thought it'd be best to ask someone before going ahead with this repair. Thanks in advance.
This is my first post on this forum and I am surely in need of your expertise I am going to attempt fixing my 1999 boxster dme. The car has had a variocam problem ever since I bought it few months back. After replacing the solenoid I traced the problem to the ECU. I called around and got a quote of $650 to solve this problem. I decided to try and fix this myself first since for that much money I could find a used ECU and have the dealer program it for me. So I am not too worried about ruining this one. Once I got inside the ecu I found a burnt Bosch transistor with the following #30046 44108.1 9908 written on it. I've tried locating a replacement, but without much success. Any ideas where to find one or any suggestions for a different brand replacement? Btw, I have ordered a couple of IRFZ44's which are on their way. I also found these Bosch BIP373 on http://www.diyautotune.com/catalog/b...kit-p-230.html Would any one of those work as a replacement? I thought it'd be best to ask someone before going ahead with this repair. Thanks in advance.
#2
Race Director
Digikey has a very large electrical components cross reference. I tried using it but I am a software person not a hardware person and get lost.
Be careful: IIRC the early Boxster DMEs cost around $5K, so you better be sure you can pick up a working one for just $650.
Sincerely,
Macster.
Be careful: IIRC the early Boxster DMEs cost around $5K, so you better be sure you can pick up a working one for just $650.
Sincerely,
Macster.
#3
Race Director
Asked a hardware engineer and he pointed me to:
http://www.nteinc.com/
He suggested if you are unable to find a cross reference you'll to find a replacement by 'spec'. This means -- I hope I'm not telling you what you already know -- you'll have to find the specs for the existing transistor and then of course find a transistor that has similar (close enough?) specs. There is of course the footprint/shape/form factor to consider. While the two devices may be similar in spec they may have dissimilar forms.
Sincerely,
Macster.
http://www.nteinc.com/
He suggested if you are unable to find a cross reference you'll to find a replacement by 'spec'. This means -- I hope I'm not telling you what you already know -- you'll have to find the specs for the existing transistor and then of course find a transistor that has similar (close enough?) specs. There is of course the footprint/shape/form factor to consider. While the two devices may be similar in spec they may have dissimilar forms.
Sincerely,
Macster.
#4
Macster, thank you for the quick reply, still can't find any specs on that bosch 30046 transistor or any reference to it. Just picked up a used boxster DME on ebay for $150 as a backup unit. Also ordered a bip373 bosch transistor and still going to try and repair my old DME. Will keep you posted with the results. Thanks again.
Simon
Simon
#5
Race Director
Macster, thank you for the quick reply, still can't find any specs on that bosch 30046 transistor or any reference to it. Just picked up a used boxster DME on ebay for $150 as a backup unit. Also ordered a bip373 bosch transistor and still going to try and repair my old DME. Will keep you posted with the results. Thanks again.
Simon
Simon
Before you put the repaired or replacement ECU in the car you want to be darn sure you have eliminated anything wrong in the wiring system.
The risk is obviously you could 'fry' the repaired/replacement ECU.
Sincerely,
Macster.
#6
Thank you for input Macster, I really appreciate it. I think I could have fried that transistor by experimenting. I started playing around with the wiring after I've replaced the solenoid (don't have to mention what pain in the neck that was without dropping an engine) and still couldn't activate bank 2 with the durametric tool. After much frustration and right before tearing into the engine again to replace the whole camshaft adjuster mechanism, I decided to switch the wires coming out of dme so that bank 1 wire triggers solenoid 2 and bank 2 wire activates solenoid 1. Then I was able to make bank 2 solenoid work (get the rpm drop and rough idle) and not able to make solenoid 1 work. Which then led to a brilliant idea, or so it seemed at that time, to hook both solenoid wires to a working bank 1 dme signal. And to my surprise it worked, i got an even rougher idle when activated and the check engine light didn't come on after driving few hundred miles. I was able to pass the inspection and thought I cheated my way out of this. Although after about a week of driving the check engine light started to blink just for a second or so usually on deceleration (in the region of 2500 to 1500 or so rpm) and a noticeable loss of power for that split second could be felt. Then I connected the wires back to where they originaly were and everything went back to the previous state of constant check engine light and not working bank 2 solenoid. So my guess is I could have cooked that transistor by running the two solenoids together. Still waiting on my replacement dme to come in so I can open it up and compare it to my fried one. I'll have an update as soon as I get it. Thanks again.
Sincerely,
Simon
Sincerely,
Simon
Last edited by szekas; 05-21-2012 at 10:31 PM. Reason: learned a few new things
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#8
It's been a while, just wanted to thank everyone for your help. I've replaced that burnt transistor with BIP373 and it seems to work just fine. Have been driving the car for few weeks now, no issues so far.