CMP Circuit Code NO SENSOR?
Hey all, I am completely stumped and looking for some insight.
This truck was brought in to us from a customer who JUST bought it from a local mining company. The truck only has 65K miles but looks like it has over 300k based on the condition!
Customers complaint is MIL on, found codes P0365 and P0369 indicating circuit fault on Bank 1 Sensor 2 Camshaft Position sensor. After looking all over the engine and through service information I can only find 2 cam sensors one on each bank camshafts. So I scoped both cam sensors and crank sensor, all look good. Performed deep measure and used a frequency math channel on a long buffer and found no glitches. I turned the diag in as a likely intermittent bad cam signal caused by failed sensors and recommended replacing both (yeah it was a guess). I installed both sensors and after two key cycles both codes return. I then measured timing of the camshaft sensors to crankshaft sensor compared to a known good waveform and they are on.
At this point I decided to purchase a short subscription to Motorcraft service information. Looking on there I found the description of the code (attached) is indeed Bank 1 SENSOR 2 circuit. So I looked at description and operation of cam sensors (attached) and found it says "Engines with 2 camshafts and variable camshaft timing (VCT) are equipped with 2 CMP sensors. Engines with 4 camshafts and VCT are equip with 4 sensors" This vehicle does have VCT, there are solenoids in both valve covers. I believe it has 2 camshafts based on valve cover shape and putting an inspection camera in the oil fill tube. So I looked up location of camshaft sensors (attached) and the illustration shows only the 2 camshaft sensors. I then looked at wiring diagrams (attached) and found again only 2 camshaft sensors.
What am I missing? How can I have circuit codes for a sensor that does not exist?
I looked at current PCM software version and found it is not the current version. I will try a re-flash in the morning, maybe incorrect calibration file? I would assume if the calibration file for the 4 cam motor was installed I would have these same codes for Bank 2 sensor 2 not to mention several others like VCT actuators?
This is a capture of a 2011 F-250 6.2 with cmp codes and intermittent stalling. CH A is the bad ckp and the ckp output voltage is too low at idle, causing the cmp codes and the intermittent stalling. The fix is to replace the ckp. CH B good cmp 1 CH C good cmp 2
I measured the crank signal amplitude on my wave form and found about 3.3-3.5 volts. The known good I have is about 4.5-4.7 volts, I guess I will try a crank sensor. I am still curious why I have a cam sensor circuit fault and code setting criteria describes loss of the bank 1 sensor 2 signal which is not present on this motor?
You may want to disconnect sensors 1 at a time and then perform KOEO/KOER On Demand Self tests to identify what faults trigger with the cmp sensors disconnected. This may help identify the sensor.
Do you happen to have the waveform files you can post? Have you looked at charging system? And when you say key cycles, is that with engine running or KOEO?
Here is the Crank and both Cam signals. I have not looked into charging system however I don't see much noise in my signals. Two key cycles with engine running.
We had one of these in the shop several weeks ago with the same codes. The crankshaft sensor was bad.
Well, the fix was a PCM. I replaced the crankshaft position sensor as several others had this issue and my signal amplitude was low (3.3 Volts). After replacement my signal amplitude increased to 7 volts (better than my known good). However after two key cycles the code returned. I then unplugged the sensors one at a time documenting what codes set as suggested by Chris Snyder. I found with…