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108 and 99 are the supply voltage and the ground for each of the sensors and should have continuity between each of the bonnet connectors as they are spliced somewhere in the harness/setup at least that is what is shown IMG_20190523_224917.jpg
 

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Discussion Starter #23
I don’t have a lot of time today to check this out on the car. But it seems like pin 2 should have continuity between all 3 sensors and same with pin 3. I also haven’t checked any wiring from the speed sensor... could be a short coming from that.
 

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Discussion Starter #24
Also what is the line and box inside the connectors between pin 1 and 2? Is it saying they are connected at the plug?
 

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the little line inside the box is an internal connection ,possibly could get an ohm reading accross those for reference....the dotted oval line designates shielding from electrical "noise" usually and as it is there connected to ground
 

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Discussion Starter #27
I’m back. Sorry for delay. I’m gonna run through continuity tests again between connectors. I’ll update when I get it all finished.
 

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Discussion Starter #28
Ok finished. These were the ohm readings of each pin combination. If a pinout isn’t listed then consider it open. Here are my results:

With ECM unplugged,

G61 pin 2 - pin 2 G66; .3 ohm
G61 pin 3 - pin 3 G66; .3 ohm
G61 pin 3 - pin 3 G28; .3 ohm
G66 pin 3 - pin 3 G28; .3 ohm

With ECM plugged in,

G61 pin 2 - pin 3 G61; .3 ohm
G61 pin 2 - pin 2 G66; .3 ohm
G61 pin 2 - pin 3 G66; .3 ohm
G61 pin 2 - pin 3 G28; .3 ohm
G61 pin 3 - pin 2 G66; .3 ohm
G61 pin 3 - pin 3 G66; .3 ohm
G61 pin 3 - pin 3 G28; .3 ohm
G66 pin 2 - pin 3 G66; .3 ohm
G66 pin 2 - pin 3 G28; .3 ohm
G66 pin 3 - pin 3 G28; .3 ohm
 

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OK, digested again, first I believe that the wiring is all functioning as intended, you have checked and confirmed this. Since sensor two is operational it also follows that sensor one is recieving a ground connection and a power source ,the +12v. and the ground,since they share (splice)in wiring diagram. Now I believe this is how they (two sensors) work, a "potential" is set up within the sensor itself +12v and ground. as vibration occurs an electronic "gate" allows voltage to increase/decrease (which you have observed as engine rpms increase/decrease, without an ocilloscope cannot tell if it is digital pulsed/modulated or purely analog, it matters not. The sensors are different in their "tuned" frequency so if there is knocking (which would occur in all four cylinders) the two would get different responces thus signalling ECM....you could have two bad #1 sensors which is highly doubtful or bad input "receiver" circuit in the ECM . When you unplug sensor # two you should get "low voltage" code there .....correct? so I would go back to junkyard and get "bonnets" off knock sensors and put your good sensor #2 and "pin in" to sensor #1 circuit, that will tell you if it is the ECM once and for all. Even if a hot +12v wire were to touch/short to #1 sensor "input" wire it would not cause it to fail since it gets that voltage at some point in the rpm range......
 

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edit
"as vibration occurs an electronic "gate" allows voltage to increase/decrease (which you have observed as engine rpms increase/decrease" this is the inputs to pin outs #106 and #107
 

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Discussion Starter #31
So basically you want me to jumper G66 to G61 bonnet to see if I can get any voltage readings off the bank 2 sensor to determine if my ECM is actually bad?
 

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you know G66 works (cyls. 3&4) as get voltage variation....... as throttle is moved..... so if possible get a used G66 bonnet connector that plugs into the G66 and "gender" change it using some small bayonet (probably have to trim) connector to plug into the G61 wiring and actually could do same with the new G61 sensor you bought to also confirm it is good, gonna see if I can get pic from ECS web page to see what connector actually looks like
 

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some place like an ACE hardware sells male and female "bayonet" style electrical connectors ,the most common has a 1/4" /.250" blade /tab width which you see everywhere on appliances ,but they make/have really small ones with .110 width you can trim down and get in the bonnet with a little fanagling and securely
 

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Discussion Starter #34
G61 is green G66 is blue. They are similar oval connectors just slotted differently so they can’t be connected wrong. I can maybe just trim that edge and maybe get the connector plugged in. I’ll work on something tomorrow morning and give an update.
 

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the smallest male and female bayonet connectors will work....piece of wire, male on one end ,female on the other end ,that way you save a trip to the salvage yard
 

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as a sidebar they both function the same ,however I believe they are "tuned" differently in the sense their harmonic frequencies are different
 

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while system is "on"(where you are getting a good power reading to ECM from G61 sensor plugged into G66 bonnet) check for power at G61 bonnet, should have +12vdc at pin#2 across to pin#3( ground) if so, and you have/had good continuity from G61 bonnet pin #1 to ECM connection #106 pinout proven by the lamp bulb then itbwould confirm it isnthe ECM....ugh....really unusual
 

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Discussion Starter #39
I’m getting my readings from vag tool block 26 but I can back probe G61 bonnet with G66 plugged into it.
 

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leave G61 sensor plugged in to the G66 bonnet/loom ,take the G66 sensor out of G61 bonnet/loom and see what the voltage is with multimeter, should get a reading of +12vdc. with positive probe on #2 terminal on inside of bonnet and negative probe on #3 terminal on inside of bonnet
 
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