Ducati.ms - The Ultimate Ducati Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
2,050 Posts
Discussion Starter #1
Still having issues with my crank sensor. The resistance of the sensor is within spec, but I'm only getting 2.5v on the harness side - I thought it was supposed to have 5v like all the other sensors... Am I wrong? Can't find any voltage specs in my manuals, they only list resistance of the sensor itself.

If it is low I think I may have an ECU problem.
 

·
Premium Member
Joined
·
3,494 Posts
Still having issues with my crank sensor. The resistance of the sensor is within spec, but I'm only getting 2.5v on the harness side - I thought it was supposed to have 5v like all the other sensors... Am I wrong? Can't find any voltage specs in my manuals, they only list resistance of the sensor itself.

If it is low I think I may have an ECU problem.
The crank sensor differs from others like temp or oil pressure in that it generates pulses. The others vary in resistance and modify the voltage that the ECU sees. It's a different animal.
 

·
Registered
Joined
·
2,050 Posts
Discussion Starter #3
But if there is a voltage present, then there has to be a correct/incorrect reading. Maybe it is 2.5. I don't know... No one lists specs.

The problem is I replaced the crank sensor with a used one... It worked fine for 150 miles then started repeating the same problem again. I've ordered a brand new one now, I'm not going to get another used item and end up second guessing the fix.

The sensor exhibits correct resistance. It seems to work intermittently. All other issues have been checked and ruled out (including the TPS, relays, temp sensor, air pressure sensor, coils, fuel delivery, eprom, etc).

What I'm trying to do is determine if it is indeed the sensor (again) or if I am dealing with an ECU problem.
 

·
Chilehead
Joined
·
6,982 Posts
The sensor generates an analog signal, you will need an oscilloscope to check it.

2.5 V is probably the bias voltage, which is as one would expect.

The sensor on my ST2 got replaced with a new one last year, as I was having cutting-out problems at higher temps, problem solved (I had already tried replacing the relays).

Tom
 

·
Registered
Joined
·
2,050 Posts
Discussion Starter #6
It was a twofold problem for me.

The harness side was fine; the (used) replacement sensor I installed had a hairline fracture in the cylinder of the body. It had flexed slightly after I installed it, and was making it contact against the timing gear (the gear had chewed the face of the sensor!). So I installed a brand new one. Problem one solved.

The other issue was I had a short circuit coming off the regulator due to a power wire rubbing against the engine. Rewired it and installed a MOSFET kit while I was in there. Problem two solved.

Don't know which was the real culprit to be honest! Haven't had an issue since. I suspect the CPS was a red herring due to the short circuit... It was the power wire that runs directly to the ECU.
 
1 - 6 of 6 Posts
Top