I purchased a 2016 FIAT last year with the P0339 DCT (crankshaft position sensor Intermittent).The car is in limp mode and wont go over 3500, it cuts out when the RPMS hit or exceed 3500.
I was a parts changer last year and placed the crankshaft position sensor. The code didnt go away and came back soon as the motor was cranked.
I thought it didnt work due to the sensor being unlearned, so I took it the the Chry$ler dealership where the charged me for an unsuccessful crankshaft learn.
They came back with it its probably the tone wheel, reluctor wheel. I didnt get it replaced because the entire motor has to come out to replace the wheel.
About a month later, it wouldnt start after changing the oil. Had it towed back to the Chry$ler dealership and the service advisor said I needed a new engine due to shininess in the oil that probably clogged the VVT.OK.
A month later, I had a replacement motor installed from a 2017 with the brand new Mopar tone wheel. The P0339 is still there!
After going thru some basic multimeter diagnosis, I discovered the 5V signal will not pull down to 0 when the care is running.
With the latest sensor pulls down to ~4.6 with the car running and stays there. (I've installed 3 sensors, a used one from Chrysler and two from O'riellys $170)
Checks done thus far:
- The 5V reference is good with the key on
- 5V signal wire reads 5V with the key on, 0V with the key off and ~4.6 with car running with no variation.
- Harness ground to battery ground is less than .1V No excess voltage
- Sensor harness ground to ECU pin continuity is good
- Sensor harness signal to ECU pin continuity is good
- Sensor harness to ground ohms <.3 per service manual
- I can pull the 5V signal down to 0 with the key on using a test light connected to the sensor harness ground and signal wire
- Weird: The battery has been disconnected multiple times for hours and the radio stations are still saved!
At this point, I'm not sure if replacing the ECU will make a difference since I was able to pull the signal down to 0 with a test light.
Hoping someone has a suggestion because Im out of options, things to test and losing my mind in the process.
I dont own an Oscillator yet.
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