I guess we need to become electricians now to work on these things! I love the "remember to check expiration date on gloves" part, I thought only Hybrids were doing this, I guess now its coming across the board.
New Injector service warnings
- Thread starter 68skylark455
- Start date
Cat has been doing this for years, ecm converts the voltage from 24dc to 110ac. It's not a big deal but you do want to mind where you stick your hands...
Normal 110 will just get your attention unless you have a pacemaker, but 20 amps wouldn't be pleasant.....
Personally I would NOT take this lightly...we are not only talking about enough voltage to penetrate you, but there is some serious current too. It generally takes less than 1 amp to kill you.
ben
ben
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Yep, thats why I said electrician. My brother is a certified electrician and he has told me that several times. When the toyota hybrids came out and they said you have to flip a switch and then wait atleast 5 min for it to discharge I decided I didn't work on hybrids
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Yeah, that is way more than enough to fricassee your brain.
25 milliamps causes involuntary muscle contraction. 50 milliamps across the chest will drop you like a sack of crap....dirt nap style. Say for example one hand on a grounded object and the other on a hot wire. 20 amps @ 240 volts is enough to kill you and everyone around you.
The only reason that many people have been zapped by a 110 20 amp outlet at home and not died is because humans and all the stuff we wear make for bad grounds. Get sweaty, and grounded somewhere other than through your rubber soled shoes......and 110 will end you. 20 amps @ 240 isn't even a contest.
25 milliamps causes involuntary muscle contraction. 50 milliamps across the chest will drop you like a sack of crap....dirt nap style. Say for example one hand on a grounded object and the other on a hot wire. 20 amps @ 240 volts is enough to kill you and everyone around you.
The only reason that many people have been zapped by a 110 20 amp outlet at home and not died is because humans and all the stuff we wear make for bad grounds. Get sweaty, and grounded somewhere other than through your rubber soled shoes......and 110 will end you. 20 amps @ 240 isn't even a contest.
If they don't teach the techs to air check the gloves and wear appropriate over protectors there will be serious injury. I used to teach union electricians about this stuff I have been taught by some very smart people and seen some very gruesome accidents. Gotta respect electricity. if you screw up even once you pay right then....no 2nd chances.
Probably a bit bigger, but remember, the high current is only for a few milliseconds (probably less on a stock tune). This means the average current is low, probably similar to the current injectors.How big is the alternator on these trucks?
It probably uses a digital DC to DC converter, which are typically small. Sounds like they have a 240 volt DC rail inside the ECU that charges capacitors, which are then discharged to the injectors, giving a momentary high-voltage DC pulse, which, since it repeats, could be considered AC. This appears to be very similar to a CDI ignition, but with more current behind it.
Kind of cool, IMO. But then, I'm a nerd who loves all kinds of digital controls. I'm just saying, I'd take one!
I agree its very cool what they can do now. The pictures of the injector have it all cut out to see the inside workings and its about the size of a sharpe marker just a little longer. I just hate being in the field and not having the training aspects of a dealership who sends you to school. Then again, being self-employed has its benefits as well like my only "boss" is my father and he isn't bossy.:thumb:
There are alot more vehicles coming out that have lots of "electric" accessories like power steering pumps, water pumps, and even rack and pinion sets. Take a look at the breakdown of the Hybrid Tahoe/Escalade transmission/generator its fricking cool!
There are alot more vehicles coming out that have lots of "electric" accessories like power steering pumps, water pumps, and even rack and pinion sets. Take a look at the breakdown of the Hybrid Tahoe/Escalade transmission/generator its fricking cool!
yep, exactly. I doubt the alternator is any bigger. Doesnt need to be...as Dave said, thats what capacitors and the FETs/drivers and stuff are for.
ben
Actually, they probably use an inductor or bank of inductors for the voltage pump(s). Caps do not multiply voltage, they only store it. It is a simple thing to flash an inductor (you all know them as coils on gas engines) and get a voltage spike from the flyback when the current stops flowing.
In this case, I suspect they are simply flipping the polarity on the inductor.
The physical size of the inductor will depend on the amps supplied. An inductor about the size of you thumbnail would be more than sufficient for this application in my opinion.
But, what do I know.....
In this case, I suspect they are simply flipping the polarity on the inductor.
The physical size of the inductor will depend on the amps supplied. An inductor about the size of you thumbnail would be more than sufficient for this application in my opinion.
But, what do I know.....
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ahhh ok I see now. Isnt that what happens when you turn a relay on and off.....if you are driving the relay with a microcontroller or something, thats why you need the diode...to prevent the flyback spike from flying the microcontroller??
That is what I meant by a DC-DC converter. That's how we designed "Boost" and "Buck-Boost" converters in school - use a sufficiently sized inductor to give the voltage rise you want (with a reasonable duty cycle and output/filter capacitor size).
I was simply speculating that they could have one (relatively) large DC-DC converter used to regulate a 240V DC rail, which then charges capacitors to drive the injectors. Although it might have been easier/cheaper to do it the way Fingers described, with one inductor per injector.
My initial thought was to use a 240V rail and capacitors (which should be an easy to control method), but that may be too slow to respond. I was just going off the top of my head.
I would be very interested to see the inside of the new ECU. Even just hooking a scope to the injector harness could provide some interesting details.
unfortunately the ECM's are on a 6-month parts restriction/hold.
So basically unless an ECM fails and needs to be replaced under warranty, you cant just go to the dealer and order one over the parts counter.
I dont know if its a supplier issue or GM is trying to stall the aftermarket???
Its a Bosch E86...I think thats about all that anyone knows about it.
ben
So basically unless an ECM fails and needs to be replaced under warranty, you cant just go to the dealer and order one over the parts counter.
I dont know if its a supplier issue or GM is trying to stall the aftermarket???
Its a Bosch E86...I think thats about all that anyone knows about it.
ben