It is a 2005 E-150 Van 5.4 2v engine 60k miles. After warmed up and under partial load this thing misses, Scanner shows very negative short term fuel trim when the missing occurs -29% both banks. There are no misfire codes. There is a p0340 but it has been happening for awhile and hadn't been affecting performance. help me fix this so wifey doesn't decide it's time for a new ride.

From reading Ford documentation the CPS is only used once during a drive cycle and that is at start up. I have ran the through the diagnostic flow chart and it ends abruptly that this is an intermittent problem. Ie it can't be replicated by three rpm run ups above 1500 rpms. My plan today is to follow through the flow chart as if the failure is being detected during the initial testing phase. Will probably also replace the connector to the CPS. The CPS is a new motorcraft. One thing that can cause issues is noise in the circuits with the alternator being the usual suspect. I did have .125 milli-volts of ac on the charging system. I now have that down .015 milli-volts with the replacement of the alternator. The new alternator did bring the voltage up to 14.2 - 14.5 range. It had been down as low as 12.8 with air on and the old alternator.

P0340
Camshaft Position Sensor A (Bank 1) - Circuit Malfunction

Status of this DTC
Confirmed DTC

Engine state when the fault appeared
Freeze frame trouble code: P0340
Fuel system status 1: Closed loop
Fuel system status 2: Unused
Calculated load value: 80.0 %
Coolant temperature: 195 °F
Short term fuel % trim Bank 1: -5.5 %
Long term fuel % trim Bank 1: +3.1 %
Short term fuel % trim Bank 2: -6.2 %
Long term fuel % trim Bank 2: +4.7 %
Engine RPM: 2161 rpm
Vehicle speed: 42 mph
Timing advance: 12.0 °
Intake air temperature: 82 °F
Maf air flow: 10.34 lb/min
Absolute Throttle sensor position: 33.3 %
Oxygen sensor voltage bank1 sensor1: 0.805 Volt
Short term fuel associated to bank1 sensor1: -3.1 %
Oxygen sensor voltage bank1 sensor2: 0.595 Volt
Short term fuel associated to bank1 sensor2: +99.2 %
Oxygen sensor voltage bank2 sensor1: 0.800 Volt
Short term fuel associated to bank2 sensor1: -6.2 %
Oxygen sensor voltage bank2 sensor2: 0.660 Volt
Short term fuel associated to bank2 sensor2: +99.2 %
Time since engine start: 394 seconds
Fuel rail pressure relative manifold: 39.9 psi
Commanded EGR: 56.1 %
EGR error: +4.7 %
Commanded evaporative purge: 50.2 %
Fuel level input: 99.6 %
Number of warn-ups since DTCs cleared: 3
Distance traveled since DTCs cleared: 11 miles
Evap system vapor pressure: 32.268 inH2O
Barometric pressure: 30.1 inHg
Catalyst Temperature bank 1, sensor 1: 1488 °F
Catalyst Temperature bank 2, sensor 1: 1488 °F
Control module voltage: 14.655 Volt
Absolute load value: 66.7 %
Fuel/air commanded equivalence ratio: 0.999
Relative throttle position: 20.8 %
Ambient air temperature: 77 °F
Absolute throttle position B: 54.9 %
Accelerator pedal position D: 40.8 %
Accelerator pedal position E: 46.7 %
Accelerator pedal position F: 35.3 %
Commanded throttle actuator control: 32.9 %


Report generated with EOBD-Facile App compatible with iPhone/iPad

 

May I suggest you reread that documentation again (or it is in error). The Cam Position Sensors are used all the time to verify proper ignition, ie determine cyl #1 and establishing firing order, as well as variable cam positioning and other things. See https://www.ford-trucks.com/forums/1...l#post15723152

 

This same thread is in the Full Sized Vans forums where I questioned the rationale of the CPS's intermittent behavior not affecting engine operations---same citation its not relevant.

Because I know that's not the case I stepped away from the thread---nothing to offer at that point. I mean disconnect the CPS and see what happens.

 

Gentlemen: Allow me to add - along with my apology - some additional information on the CPS and code 0340.


I strongly expressed doubt of this statement here as well as in another thread started by the OP - https://www.ford-trucks.com/forums/1...l#post15723152

@JWA added -

I later noticed in both threads @wtroger stated he was talking about 5.4l "2v". My vehicle is a 5.4l "3v". Not only do I need to pay better attention to the OP before posting, that got me thinking -----
I've OFTEN seen where members would "unplug" the CPS as some sort of a diagnostics procedure, only to state that it made "no difference", and if not reach a false conclusion therefrom, at least ponder WHY. @JWA suggested to me "disconnect the CPS and see what happens", so I did just that. But not casually. I did so with Torque Pro running! And I find we're ALL right to some degree but spoke without sufficient specifics.


It appears that on the 5.4l '2v', @wtroger is correct, the CPS is probably used for ignition & timing verification early in the drive cycle (if not only at startup). That of course would make logical sense in absence of variable cam operation. If the chains are on properly at startup - we're not going to monitor for a chain jumping time while driving! However, an over-retard or over-advance DTC can be detected and set (P0021 - 22) on either engine configuration. Everything we need to know after that can be determined solely by the CKP. Then the "circuit" is monitored continuously for opens and shorts (DTC 0340).


Things work differently in the '3v'. In addition to the above operation, the PCM sets up a "closed loop" operation for managing the Phasers (exactly like the fuel systems "open/closed loop" between O2 sensors & injectors). A flag is set and maintained in the PCM called "Conditions Correct for Variable Cam Timing" (VCTENA). When this flag is set, the PCM is constantly monitoring cam positions and diddling with pulse-width duty cycle (CAMDCR) to the VCT Solenoids to establish the desired retard (RCAM) shift between crankshaft position and camshaft positions.


When either CPS is unplugged (on my '3v'), VCTENA immediately goes false or will not go true when all other conditions are met for enabling variable valve timing (25% engine load and > 800 rpms). Unplugging, as @JWA states, appears to "have NO EFFECT on engine operations--". On a 5.4l '2v', that would be in fact true. On a '3v', that is true at idle or under <25% engine load or < 800 rpms. Otherwise, the effect of variable valve timing is merely sacrificed. That is ONLY noticeable in fuel trim readings, spark advance readings (and probably MPG), and engine torque power under certain conditions (then only slightly).


HOWEVER, in BOTH CASES ABOVE, the appropriate DTC will be set according to their respective rules. NOTE: A P0340 (as is P0021, 22 etc) set as a "pending" code immediately - but require multiple drive cycles with the condition persisting before it sets a flag in the PCM (CMPFM) when it becomes a hard DTC and lights the MIL.


THE BOTTOM LINE, AND IMPORTANT CONCLUSION. UNPLUGGING A CPS is a useless exercise that has zero diagnostic value.

 

F150torqued thanks for you input very good info. Look at this graph and see what you think. Once again thanks for all your help.Here is graph (don't laugh at my Excel skills) of the fuel pressure issue i am seeing. I swapped the FPDM with another one I will swap the fuel pump relay. But unless you pros think of something else I am changing the fuel pump. Also this run was about 13 mins long no p0340 code pending or set. As you can see there are a lot of zero pressures. and that corresponds to the missing episodes

 

QUESTION. May sound dumb, but the graph would look just fine under one of the following scenarios.


Is the graph data from monitoring FP [Fuel Pump Duty Cycle (PID 1672 hex), which is in %], or the FRP [Fuel Rail Pressure (PID 168C hex), which is in Lbs pressure - relative to IM vacuum]?


If you are graphing Fuel Rail Pressure, you might try graphing fuel pump duty cycle and overlay that graph over this one in EXCEL and see if the FPDM is commanding the pump to do this flakey Stuff. Otherwise I would WTS out of the fuel rail pressure sensor. I don't think its reference vacuum could possibly change that rapidly.

 

Lb's relative to im. WTS meaning whack the s out of it

 

Yea, that's the best repair procedure I could think of given the symptoms its exhibiting. Sorta like when I ran outa ideas with my kids - just WTS out of them.


But on a more serious note. I would try to determine if the pressure is ACTUALLY fluctuating like that (ie: fuel pump duty cycle commanding fuel pump to do something stupid), or is the sensor giving stupid readings? I know of no PCM logic that would result in misfires under similar stupid conditions - but it could exist, some sort of fail safe - limp mode or something. Does the data stream look level in KOEO state?

 

The way it acted (stumbled/missed) is exactly what I have experienced when there is low to no fuel pressure. I don't think the psi readings are wrong. I just don't know what is causing it. Will see if I can get the duty cycle in the AM. I did change the FPDM today no change in symptoms. Forever more acts like a bad pump. It usually does it after about 4 mins run time. Although Saturday it did it on a cold startup. As I said today no codes of any kind. Not sure how long fuel pressure has to be down to get a p0192

 

This thing continues to baffle me. Swap fuel pump relay. No change. Fuel pressure will plummeted to zero and then bounce to over 80 psi. This then causes everything to go rich. P0172 errors. Wish me luck on my fuel pump change

 

I replaced the fuel pump an the Fuel pressure sensor. No fix *@$%. It was the F*****G computer replaced it with one of the exact same part number and short code VPN1. Runs Like A champ. I know the vin doesn't doesn't match but so far no codes of any sort. time will tell.