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Discussion Starter · #1 ·
Hello all,

I have persistent CEL P1108 (Ambient Air Pressure sensor open or short circuit) and occasional P1698 (5V sensor supply malfunction). I already tried to clear the codes via Dealertools but P1108 remains persistent.

For P1108, According to the Service Manual, I need to conduct a "pinpoint test" to check the cable for short circuit before replacing the sensor. The service manual says:

-ECM pin B41 to sensor pin 2
-ECM pin B35 to sensor pin 1

1. If i cleared the code via dealertools, do I need to do a few rides for the code to completely clear or does this mean the issue still persists?
2. ECM = ECU right? And on this bike it's located under the gas tank but on top of the airbox?
3. I presume i need a multimeter where I'm touching 1 end to the ECM pin and the other to the sensor pin but I have no idea how to do this and what setting I should put on the multimeter and what is it supposed to read?

Any guidance on this, i appreciate it. I have almost 0 electrical experience but I have a multimeter. I google pinpoint test and all I get is bullshit and companies trying to sell me shit. Can't even find a good youtube video.

Thanks in advance.
 

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So what the test you've described is trying to do is find out if there's a break or short in the wires between the sensor and the ecu.
Yes the ecu is under the tank and on the airbox.
Set your multimeter to either the lowest ohms setting, or buzzer. Since you're only testing two wires and I have no clue what color they actually are I'll call them black and red. Pin B41 is one side of the red wire at the ecu, and is pin 2 on the sensor. Touch the probes on your multimeter to the two ends of the red wire, should be a very low reading. Now do the same for the black wire. If you get a similar result then connect the probes to the black and red wire to see if the wires are shorting. If you have good resistance from one side of the wires to the other, and they're not shorting, then it's either the sensor or the ecu.
 

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Discussion Starter · #3 · (Edited)
Ok I got it.

Pin 35 and Sensor pin 1 tested correctly but I did not get any response from Pin B41 and sensor Pin 2.

The good news is I did not get any response from cross checking the pins.

So not sure what to do. Everything looks fine. What wouldn't be apparent is if I got a cut or shorted out wire down in the belly of the harness.

I guess I'll just replace the sensor and take it from there.

Thanks!
 
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