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Discussion Starter #1
Hi Guys,

Just bought a 2013 x5 diesel and it cut out on me driving home from work. Got it going again and it was displaying 4b99 injector, bank 2, activation. tried to drive it the next day and it died and would not restart. it added 4cfo misfire detection in several cylinders, 483d throttle actuator, and 4bbf injector, cylinder 6, activation. I have combed through all the posts about the water problem shorting out injectors and am trying to diagnose the problem. All the connections seam fine. the injectors all measure 180 across the terminals, I do do not know how to test them to ground, or what the resistance should be. Also how does the water kill the injector. Sorry for the long winded first post. Any help would be much appreciated.

Thanks,

Allstar
 

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Nuclear engineer
02/2012 X5 35d M57Y CPO 98K miles NOKIAN WR G3 12K miles
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16,373 Posts
They are not solenoid driven injectors, but piezoelectric injectors, presenting a reactive impedance. The electrically reactive component is a stack of 254 layers of quartz crystal that moves about one micro-inch on application of 200 VDC. In operation they run at about 6KHz.
 

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Ground should be above 100k
Put one lead on a metallic part of the engine like the injector body.
Touch the other lead on another metal part to check ground, should be below 5ohms.
Then check the injector plug each terminal to ground.
After check the ground again is below 5 to make sure your had a good ground reference point.
That is a key step because sometimes you could be touching metal and not have a good contact.

Do it for each injector, both terminals of each.

Water gets into the body and combines with the metal to create conductivity between internal wiring I think.
I had to do injector 5 and 6 2 years ago.
Check ebay with the bmw or Bosch part number.
 

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I have combed through all the posts about the water problem shorting out injectors and am trying to diagnose the problem.
Were you able to see any of the telltale signs of water intrustion Broken or missing rain gutter/aka partition, crude application of sealant... new parts..missing sound deadening material, etc.



Also how does the water kill the injector.
Corrosion inside likely interferes with the dynamic electrical impedance. As a caution it may 'ohm out' but when the DDE is trying to drive it at 500+Hz it may not look so good....
 

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Discussion Starter #6
Hi Rob, thanks for the reply. That is my problem when I test the injectors to ground they all fail so I will try again using your method. Ard there are salt stains on my intake and some of the bolts have corrosion on them, and the foam cover has a hole worn in it so it looks like a water issue.

Thanks again will keep you posted.
 

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Nuclear engineer
02/2012 X5 35d M57Y CPO 98K miles NOKIAN WR G3 12K miles
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16,373 Posts

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Nuclear engineer
02/2012 X5 35d M57Y CPO 98K miles NOKIAN WR G3 12K miles
Joined
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16,373 Posts
Piezoelectric stack equivalent electrical circuit

Electrical Properties
As an electrical element, piezoelectric ceramics are often modeled using the Butterworth Van Dyke equivalent circuit model shown in Figure 2-8. This circuit model captures both the first resonance and anti-resonance peaks that are characteristic of a piezo element's response to driving input signals of various frequencies. The impedance bode plot that corresponds to this circuit model is shown in Figure 2-9.
 

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Discussion Starter #11
So I tested from ground to ground and I get .6 with the metre set at 200ohms. I used injector 1 body to the engine hook. Same for body ground to engine hook. Also .6 touching test leads together. When I go from injector body to injector pin I get 1_. which to me means no continuity or bad ground. It does this on all of them. Is my method correct. I was hoping to isolate the bad injectors in bank 2 and replace them but this result is telling me they are all bad. also noted today that the valley that houses the injectors is very crusty. Thanks to everyone who chimed in.
 

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Nuclear engineer
02/2012 X5 35d M57Y CPO 98K miles NOKIAN WR G3 12K miles
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. Also .6 touching test leads together.
Lead resistance. Must be added to any resistance measurement. Any resistance less than an ohm should be measured with a 4-lead Kelvin Bridge.

There is little sense in using a meter when one does not understand its indication.
 
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