[SwissXC90]

I will approach this from the viewpoint of tracking down an intermittent electrical contact problem.

For reference I found a 2005 wiring diagram, it will be similar (I hope) to the 2003 model.

There are two Camshaft Posiiton Sensors:
7/172 Position sensor, camshaft, intake side
7/173 Position sensor, camshaft, exhaust side

Both are wired directly from the sensor to the ECM, without any connectors in the way. This is done for maximum reliability.

So for intermittent contacts you can only have the following issues:
Poor connection at either connector (sensor or ECM)
Wiring loom fault (abrasion with intermitten short to ground, or a wire break)
ECM fault (faulty inputs for the camshaft position sensors)


I recommend the following:
Inspect and clean the sensor connector, and inspect and clean the ECM connector. Use contact cleaner spray to clean them.
Be suspicious of any connector which is dirty, oily, greasy, or corroded,
Ensure the pins has a sufficiently tight fit on their mating surfaces, so that no intermittent contacts can result. this can be dificult to determine unless you have a mating pin you can use to check pin contact force.
Inspect the cabling from the sensor, along the loom, to the ECM.
Look for signs of adbrasion through vibration and rubbing on any surfaces.
Look for any signs of damage anywhere: such as cable loom pulled tight over any obstruction.

Both sensors have a red, a black and a blue wire
Red and black will be the power, and blue the signal
But all 3 are equally important

Red goes to ECM pin A:57
Black goes to ECM pin A:65
Blue goes to ECM pin A:47 for device 7/172 and to pin A:27 for device 7/173

Good luck!