why did my ecu blow???

[Beanokid69]

So a few weeks ago I blew out one or more of the driver chips on my ecu....My question is what can I do to figure out why this happened because I dont want to put in my other ecu if there is a problem somewhere blowing my ecu's.

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[yokotabrat]

Looks like your ISC might be shorted. Here's some info here:

http://www.dsmtuners.com/forums/showthread.php?t=116585

It looks like in your picture IC107 is the chip that's fried which would point to the ISC. You just need to measure the coils on the ISC to verify they're not in spec and replace the ISC before you put another ecu back in.

 

[BUCK]

The CLASSIC scenario is P/S leaks kill Voltage Regulator in Alternator - V/R fails to HIGH Voltage - HIGH VOLTAGE KILLS ECU - Throw in some clicking under the dash & you got the whole package~!

 

[steve]

Bad angle on the picture but it looks more like IC106 that's blown. It drives the BCS and FPS. If the solenoids are disconnected the connector from the harness is still hot with 12v on one pin and the ECU connected to the other. Add a little water and you get ECU smoke.

Steve

 

[Beanokid69]

well I have absolutly no power steering leaks and my altie is only maybe 6 months old, and as far as water getting on my ecu!!! never. not with a fresh dsmlink chip.

and where are you guys getting these numbers? I would like to see if there is a diagram floating around so I can compare directly to my ecu, so far I have been told to check my isc a few times and now my BCS and FPS too. Thanks for the info though. What should I look to first? Right before the ecu went....I had been having problems with the car bucking and loosing all throttle power for a few seconds then kick back in again and the rpms would jump up and down like the gauge was shorting out......

 

[Beanokid69]

oops sorry forgot about the url the driver that blew was

IC106 is Wastegate and Fuel pressure solenoids(turbo only)

and I want to go ahead and check the sensor ground trace too since I was throwing a 0022 (CAS) code too...but I only didnt have any volts (which should have been 5v) in the thing black wire that goes to that sensor....I believe its the rpm wire (the one that you tap your MAFT into)

I dont know where to start. I have never heard of a wastegate solenoid and I dont have a FPS I dont really need to check the sensor ground trace since Im replacing the entire ecu.....I just dont want this to happen again, Im going to go ahead and rewire the ecu and try to test the ISC, if someone knows of a page on that, that would be awsome.

 

[steve]

as far as water getting on my ecu!!!

Ah, water reaching the loose connector under the hood. Please read my posts more carefully.

 

[Beanokid69]

oh my bad I had just woken up....I just went and tested the ISC and the harness was hard to get off so I doubt that water got into it. I also noticed that there are a few exposed wires on the ecu pin harnesses from where my safc was uninstalled from. My only guess is maybe one of those touched and shorted. Still cant figure out why I wasnt getting any volts in that wire to my CAS thats whats bugging me because I didnt smell any smoke this last time the car died but I did hear the ecu click, A few months ago maybe 3 I did smell and see smoke which looked like it came from under the dash but my car ran fine after that and I thought nothing of it. Do you think the ecu could still have operated properly even with that blown driver since I dont even have an FPS. And Something else is the problem that wont let my car turn over? I cant figure out why my ecu wasnt putting volts to my CAS but still would throw codes. I see it as if your ecu is out its fully blown not partially but I could be wrong I dont know.

 

[yokotabrat]

The wastegate solenoid would be the bcs (boost control solenoid). If you're not using this or the fuel pressure solenoid the blown driver won't affect you since it's only used to control those two things.

I'd start by tracing the loose wires in the harness. Find out where they go to in the ecu and that might point to your CAS problem or other problem.

Here is the ECU pinout for the 1gs: http://www.vfaq.com/mods/ecu-harness-1G.html

I'd also use the pinout diagram to troubleshoot that the wastegate solenoid line and the fuel pressure solenoid line still isn't shorted. Check on the harness side (pin 57 and pin 105) and make sure they aren't shorted to ground so that you don't blow the driver on the other ecu if you decide to use it.

 

[Beanokid69]

ya I checked all the pinouts and pin 21 or 22 I cant remember which one....isnt putting out any volts at all....to my knowledge the ecu should put out 5v and the CAS pulls those 5v, moving the sensor. Im not getting my 5v!!! Im gonna swap the ecu today and see if i get my voltage/car started. Which im 99.99% sure will happen because Iv traced this problem all the way back to this dumb ecu and theres nowhere else it can be finally. I keep you guys updated as soon as I can find a jump.

P.S. Optima batteries suck

 

[steve]

A few months ago maybe 3 I did smell and see smoke which looked like it came from under the dash but my car ran fine after that and I thought nothing of it. Do you think the ecu could still have operated properly even with that blown driver since I dont even have an FPS.

Again, If that is IC106, it drives the Boost Control Solenoid (BSC or Wastegate Control Solenoid) and the Fuel Pressure Solenoid (FPS).

All DSM's started out life with these devices.

If someone removed then and just left the wires hanging loose under the hood then water or oil could short the pins in the connector and cause the driver to blow up. Besides smoke escaping you might not notice anything since the solenoid isn't in use. If the driver burned up the circuit board other parts of the ECU could be effected.

I can't make any sense out of the rest of your post.

 

[steve]

Check on the harness side (pin 57 and pin 105) and make sure they aren't shorted to ground so that you don't blow the driver on the other ecu if you decide to use it.

Shorting the driver control lines to ground won't damage the driver, shorting them to 12v is what causes the fireworks. The driver is only rated for something like pulling 2A to ground for a couple of milliseconds. Exceed that and they burn up.

 

[Beanokid69]

hmm...well I wasn't the person that removed the FPS and that spot where all those plugs SHOULD be are gone and im not sure where the wiring could be located so I guess I have to find them. Thanks for all your help, right now im charging my battery to try and start it.

 

[Beanokid69]

car still doesnt start...still dont get any voltage coming out from pin 22 which is top dead center sensor

 

[Beanokid69]

well no I get .19 volts....but aren't I supposed to be getting 5v? And still no voltage from the thin black wire on my CAS harness Which I think is the same wire as pin 22 am i right?

 

[Beanokid69]

Iv done the research and The two wires im talking about are in fact the same wire. Pin22 and the thin black wire on the CAS harness are the TDC sensor wire and should read 5v from the ecu and it reads .19....This is my second ecu and I know for a fact that the ecu is a good one becuase its out of my other dsm. Im still throwing the 0022 code also which is CAS related. Why is my ecu not giving the voltage my CAS needs?

 

[yokotabrat]

Just in case you see this before you see my PM, the CAS might be keeping that line pulled low. Unplug the CAS and measure the same pin on the harness side and verify it's 5V. If it is 5V, then the CAS has gone bad.

 

[yokotabrat]

Shorting the driver control lines to ground won't damage the driver, shorting them to 12v is what causes the fireworks. The driver is only rated for something like pulling 2A to ground for a couple of milliseconds. Exceed that and they burn up.

DOH! I forgot the drivers sink current instead of source. Thanks for correcting that.

 

[Beanokid69]

I have already tested the line several times with 2 different CAS's and without the CAS hooked up also. Nothing gives me voltage.