What this code means
P0016 may mean the PCM is seeing the Bank 1 exhaust camshaft and crankshaft relationship out of the expected range.
What the vehicle may do
- The MIL may illuminate.
- If equipped, the stop/start system can be disabled while the code is active.
- The engine may run rough or show misfire-related behavior when cam phasing is affected.
Possible fault areas
- Engine oil level, oil condition, oil viscosity, or oil filter concerns may be involved.
- Engine oil pressure or a mechanical oiling problem may be involved.
- The camshaft oil control valve or VCT solenoid may be involved.
- The cam phaser or cam sensor target wheel may be involved.
- Timing chain, sprocket, tensioner, or guide issues may be involved.
Diagnostic path
Open on what P0016 is telling us
On this Ram 2500HD with the 6.4 gas engine, P0016 means the PCM is seeing the Bank 1 exhaust camshaft position and the crankshaft position out of sync. In plain language, the cam and crank relationship is not where the controller expects it to be. The truck may turn on the MIL, and if it has stop/start, that system may be disabled while the code is active. It may also run rough or show misfire-related behavior if the cam phaser or oil control side is acting up. The broad areas we are thinking about are engine oil quality and level, oil pressure and oiling problems, the cam oil control valve or phaser, the target wheel, and the timing chain, sprocket, tensioner, or guides. Before going deep, start with the basic system checks, and check for any applicable bulletins or case information for this fault.
Confirm the fault and separate the monitor logic from the test path
The code sets when the difference between the Bank 1 exhaust camshaft position and the crankshaft position is more than 10.0 degrees. The monitor only runs under the right enable conditions: battery voltage above 11.0 volts, engine speed between approximately 500 - 5500 rpm depending on PCM calibration, coolant temperature above 10°C (50°F), oil temperature above between 5°C (41°F) and 10°C (50°F) depending on calibration, and engine oil pressure above approximately 220 kPa (31.9 psi). Treat those as monitor gates. For diagnosis, save the scan report and recorded data, erase the codes, turn the ignition off for a minimum of 10.0 seconds, turn it back on, then operate the vehicle under the captured conditions and the monitor conditions. Read the codes again. If P0016 does not return, handle it as an intermittent condition. If it does return, keep moving down the path.
Run the exhaust phaser cleaning routine
Next, use the scan tool to run the Exhaust Phaser 1 Cleaning function. After that routine, erase the codes, start the engine, and let it idle. It may need a test drive so cam phasing can occur and the fault can reset if the problem is still there. Read the codes again. If P0016 does not return, the cleaning routine corrected the fault condition, and the next move is to verify the repair and confirm the code stays gone. If it does return, continue with the diagnostic path.
Check whether another cam control fault is driving this
Now look back at the recorded codes. If there are active or pending camshaft oil control valve circuit faults or slow response faults, diagnose those first because they can explain why the cam is not landing where commanded. Do not treat P0016 in isolation if the control circuit or slow response side is already giving you a direction. If those faults are not active or pending, move on to the oil checks.
Check oil level, filter, and oil condition before condemning parts
Before replacing anything, check the engine oil level and condition. Look for low oil, the wrong oil filter, dirty or deteriorated oil, contaminated oil, incorrect viscosity, or aerated oil. This is one of the spots where skipping the basics can lead to a bad diagnosis. If one of those oiling concerns is present, repair the oiling issue as needed, then verify the repair and confirm the code stays gone. If the oil level, filter, and condition check out, go to the pressure and mechanical check.
Check oil pressure and mechanical oiling condition
Turn the engine off and install an oil pressure gauge on the engine. Start it and let it idle while watching the gauge. The decision here is not just whether there is pressure, but whether the reading is steady and above the engine specification. If the reading is not steady and above specification, repair the engine mechanical or oiling condition, such as an oil drainback problem, blocked screen in the cylinder head, sludge, worn main or rod bearings, damaged oil pump, pickup tube, or seal, then verify the repair and confirm the code stays gone. If oil pressure is steady and above specification, continue to the VCT solenoid and camshaft oil control valve step.
Replace the VCT solenoid and camshaft oil control valve, then retest
If the oil checks pass, turn the ignition off and replace the VCT solenoid, also called the camshaft oil control valve. After this kind of repair, the Cam/Crank Relearn must be performed with the scan tool. That relearn is required any time there has been a repair or replacement involving a CMP sensor, CKP sensor, flywheel, valvetrain, timing chain, or gears; skipping it can set a misfire fault. Connect the VCT solenoid harness connector, turn the ignition on, erase the codes, and then run the vehicle under the captured conditions and the monitor conditions. Read the codes again. If P0016 does not return, that repair corrected the fault, and you still finish by verifying the repair. If the code returns, move on to the mechanical timing checks.
Check mechanical timing and phaser-related hardware
At this point, check the engine timing alignment. Verify the timing chain and sprocket alignment, and inspect the cam sensor target wheel, timing chain tensioner, and guide for broken or faulty components. If you find an alignment problem or damaged component, make the appropriate repair, perform the Cam/Crank Relearn, and verify the repair. If no timing alignment or component issue is found, the path points back to a lack of oil pressure in the cylinder head or a faulty cam phaser assembly. Make the appropriate repair, perform the Cam/Crank Relearn, and then verify the repair and confirm the code stays gone.
Close with the diagnostic takeaway
The key with P0016 is to prove the fault comes back, clean and retest the exhaust phaser first, check for cam control faults, then work through oil condition, oil pressure, the oil control valve, and finally the timing and phaser hardware. Do not guess at the timing drive or phaser until the oiling side has been checked. For more diagnostic training, visit stepdiagnostics.com.
Final check
P0016 often needs a disciplined path: confirm the code, address phaser cleaning and related cam control faults, verify oil condition and pressure, then move into the oil control valve, timing, and ph
For more guided automotive diagnostics, visit STEP Diagnostics.
