Cam Position Sensor p0340

[Mektek]

Getting a P0340 I figured replacing the old original CPS was a good idea. However the same code continued with the new sensor.
So I tested the old sensor and found that the output latched when activated. Is that the way it's supposed to work? I have battery voltage at the connector, so that appears normal.

The new sensor output was less than 5 volts, so it has a problem. And it also exhibits the latching behavior, so I'm thinking that its normal.

Interestingly enough, it starts just fine with the CPS disconnected. Even the SES light goes out.

 

[TJBaker57]

I believe the output is a square wave.

The P0340 is a missing cam position signal.

"No change in cam activity>30 cycles
As compared to crankshaft events"

Could be a poor quality connection somewhere in the wiring.

 

[Mektek]

Swapped out the new sensor with the old one again. SES light is out and cruise control works!

I'm not sure what fixed the problem, but it's OK now. Maybe it was just a bad connection that was fixed by several plug-unplug cycles.....

New sensor will be returned for refund. It dropped the output voltage from 12v to 4.5, while the original cps kept it at 12v.

I think the latching output is normal. It's triggered by the tooth on the cam gear and stays in that state until the next tooth changes it. From other diagnostics on the tube it is possible for the sensor to produce a random short pulse which can also cause a problem.
So I'll add a CPS to the spare parts bin, just in case.

 

[Mektek]

It was easy to open the CPS and see what's inside.


I noticed that there was a "burned electronics" smell to it, even though nothing appears burned out. A rainy day project may be to replace 120 ohm resistor on the + line with a 50 and see if that bumps up the output voltage.