Thanks for all who replied. So in short, if I keep driving it with the sensor u plugged, (even though it seems as if it is running fine) I'm starving the motor of oil and it's only a matter of time before it leaves me stranded?

 

Pretty much

 

Definitely agree. But if you're trashing the motor anyway why would it matter

 

I have a f150 2004 with 5.4l engine. Did a new engine swapped. And now i don't have power in the cam sensors. Anyone experience the same thing? All fuses and relays are ok. Could it be the ECM ??

 

Sensor is telling you drivers side cam phasor not moving to correct point .
First thing check oil pressure gauge on dash is junk . . It goes bad because of broken guide pieces in oil pickup and/ or blown tensioner seals .
Drop oil pan and clear pieces but if there you must do timing job . Much cheaper than $7500 reman motor .
Any one with the will can do this job, it is doable as long as the heads are in good shape , But to hire it done is iffy. Probably better do reman then .
Driving this with sensor unplugged is causing pcm to run in a default mode .
This lack of oil pressure is going to come to a bad end .
Kinda like running your heart with a bad ekg reading -- no fix bye bye . Blame the EKG machine sensors .

 

I am having the same issue. Zero voltage to the cam sensor plugs. No broken wires as i have checked with my meter. Of course, my truck runs rough.. the cam sensors aren't even working due to no voltage from the pcm. HELP

 

I asked the Grok AI and this is what it replied. Lengthy but comprehensive. Hope it's helpful.

The camshaft position sensors (CMP) on your 2004 Ford F-150 with the 5.4L Triton engine are 2-wire variable reluctance (VR) type sensors. This is important because, unlike Hall-effect sensors in some other vehicles, VR sensors do not receive a reference voltage (like 5V or 12V) from the PCM. Instead, they generate their own AC voltage signal as the camshaft rotates past a reluctor wheel (tone ring) on the cam. If you're measuring zero voltage at the disconnected sensor plugs with a multimeter set to DC volts (key on, engine off), that's actually normal—there shouldn't be any voltage supplied by the PCM.


The rough running you're describing is a classic symptom of CMP issues on these engines, often triggering codes like P0340 (CMP sensor circuit malfunction, Bank 1), P0344 (intermittent signal, Bank 1), P0345 (circuit malfunction, Bank 2), or P0349 (intermittent, Bank 2). Since there are two CMP sensors (one per bank), the problem could affect one or both. Here's how to diagnose and fix this step by step, building on your wiring continuity checks.
Step 1: Confirm the Basics and Pull Codes

• Scan for DTCs: Use an OBD-II scanner to read any stored codes. This will pinpoint which bank/sensor is faulty (e.g., Bank 1 is driver side, Bank 2 is passenger side). If no scanner, many auto parts stores like AutoZone will scan for free. Common related codes also include cam phaser/VCT issues (P0011, P0012, etc.), as these engines are prone to timing problems.
• Battery and Charging System: Ensure the battery is fully charged (12.6V+ at rest) and the alternator is outputting 13.5-14.5V while running. Low voltage can cause erratic sensor signals.
• Fuses and Relays: Even if you checked some, double-check Fuse #18 (5A, PCM power) and Fuse #23 (20A, engine sensors) in the under-hood fuse box. Also inspect the PCM relay (in the same box). Swap relays with known-good ones if possible.

Step 2: Test the CMP Sensors Themselves
Each sensor has a 2-pin connector: one wire is the signal (usually dark green or violet, depending on bank), and the other is the signal return/ground (gray/red or brown/blue stripe). No power wire.

Resistance Test (Sensor Disconnected):
Set your multimeter to ohms.Probe across the two pins on the sensor.
Expected reading: 450-1,000 ohms (Ford spec; if outside this, the sensor is bad—common failure from heat/oil exposure).
Also check each pin to ground (engine block): Should be infinite resistance (open circuit). If low, there's a short.

AC Voltage Test (While Cranking):
Reconnect the sensor.
Backprobe the connector (probe through the back without disconnecting).
Set multimeter to AC volts.
Have a helper crank the engine (don't start it if it's too rough).
Expected: At least 0.4-1V AC fluctuating. If zero or very low, the sensor isn't generating a signal.

Repeat for both banks. Sensors are cheap (~$20-30 each, part # like DU-89 or PC643), so replace if tests fail. They're located at the front of each cylinder head, behind the timing cover—passenger side is easier to access.

Step 3: Wiring and Circuit Checks (Beyond Basic Continuity)
Since you already checked for breaks:

• Shorts to Ground: With sensor disconnected and PCM connector unplugged (104-pin connector under the hood, passenger side firewall), check resistance from each wire at the sensor plug to ground. Should be infinite. If low, trace for chafed insulation (common near exhaust manifolds or valve covers).
• Signal Wire Integrity: From sensor to PCM:

Bank 1 (driver): Signal wire to PCM pin 85, return to pin 91.
Bank 2 (passenger): Signal to PCM pin 79, return to pin 103.
Resistance end-to-end: <5 ohms per wire.

• Shielding: These wires are shielded to prevent interference. If shielding is damaged (e.g., from rodents or prior repairs), it can cause signal loss/noise, leading to rough running.

If wiring passes, unplug other sensors on shared circuits (like crankshaft position sensor—CKP, which is also VR type at the front crank pulley) and retest. A shorted CKP can pull down the CMP signals.

Step 4: Deeper Causes if Sensors/Wiring Test Good
If the sensors generate signal but the truck still runs rough:

• Timing Chain/Phasers: The 5.4L 3V is notorious for stretched timing chains, failed tensioners/guides, or stuck VCT (variable cam timing) solenoids/phasers. This misaligns the reluctor wheel, causing weak/no CMP signal. Symptoms: Rattling at startup, rough idle, power loss. Listen for chain noise; check with a scope if possible. Fix often requires timing chain kit (~$300-500 parts, but labor-intensive).
• Oil Pressure/Flow Issues: VCT system relies on oil pressure. Low oil, clogged screens, or bad oil pump can cause phaser failure, indirectly affecting CMP. Check oil pressure (should be 25-65 psi hot).
• PCM Fault: Rare, but if all else fails, the PCM could have an internal issue (e.g., failed driver circuit). Reflash or replace (~$200-400, plus programming). Test by swapping if you have access to a known-good one.
• Other Tests: Try running with one CMP unplugged—sometimes it smooths out if one bank is faulty (PCM defaults to crank sensor only). Also check for vacuum leaks, bad coils/plugs (common misfire cause), or dirty MAF sensor.

 

I checked the sensor on ohms and they both are 333. The guy I got the truck from said they are new sensors. Also I noticed all the spark plug boots are broken at the bolt on area, the engine block is broken but as long as they are on secure that shouldn’t matter. The plugs on the spark plugs are broken on the clip part and are easily pulled off but seem to be on good enough.