Quick answer
The powertrain control module (PCM) uses crankshaft-position (CKP) and camshaft-position (CMP) signals to identify engine position, synchronize spark and fuel delivery, monitor the crank-to-cam relationship, and confirm variable cam timing (VCT) response. P0335 and P0340 concern position-signal integrity, P0013 concerns the VCT actuator-control circuit, and P0016 concerns the relationship between recognized crank and cam positions. None of these codes, by itself, proves that a sensor, solenoid, phaser, timing chain, or PCM has failed.
Applicability and service-information boundary
This overview applies to the 2019-2024 Ram 1500 Classic 5.7L HEMI Gas configuration. Authorized vehicle records confirm Ram 1500 Classic 4WD applications with the 5.7-liter gasoline engine at the 2019 and 2024 endpoints. Detailed system and diagnostic evidence for this overview was verified on the 2024 application.
Calibration, wiring, circuit identifiers, scan-tool functions, sensor and target design, component access, specifications, and repair procedures can change by year and equipment. Use current service information matched to the exact truck whenever a test requires a value, connector, command, special tool, relearn, alignment, or removal procedure.
What the timing and position system does
Mechanical timing establishes the physical relationship among the crankshaft, camshaft, pistons, and valves. CKP and CMP sensing tells the PCM where those rotating parts are. VCT adds a controlled change to camshaft position so the engine can meet operating, performance, and emissions requirements under different conditions.
The system has several connected layers:
- The timing chain, sprockets, guides, tensioner, phaser, and related hardware establish and maintain the mechanical crank-to-cam relationship.
- The CKP sensor and its rotating target give the PCM a detailed reference for crankshaft position and speed.
- The CMP sensor and its target identify camshaft position within the engine cycle.
- The VCT solenoid/oil-control valve meters engine oil to a hydraulic phaser.
- The PCM calculates desired cam position, commands VCT operation, monitors CMP feedback, and compares the recognized crank-to-cam relationship with learned information.
A DTC tells you which monitor failed. It does not identify the failed part without further testing.
How CKP and CMP signals establish synchronization
The crankshaft rotates twice for each camshaft revolution in a four-stroke cycle. The CKP pattern gives the PCM crankshaft speed and angle, while the CMP pattern identifies camshaft phase so the PCM can determine the correct cylinder stroke. After it recognizes and validates both patterns, it can synchronize spark and injection and monitor whether the cam remains where the operating strategy expects it.
This relationship is not judged from one static voltage. Each sensor produces a changing pattern as its target passes. A circuit can have reference voltage and ground yet still produce a missing, noisy, distorted, or mistimed pattern. Conversely, both signals can look active while their mechanical relationship is wrong.
That distinction separates signal DTCs such as P0335 and P0340 from a correlation DTC such as P0016. If a signal is missing or implausible, prove the circuit, mounting, sensor, and target first. If both signals are recognized but their relationship is outside the learned model, oil-controlled VCT and mechanical timing become more important branches.
How oil-controlled VCT fits into the system
The PCM calculates a target camshaft position from current operating conditions. It commands the VCT solenoid, which changes oil flow to the hydraulic phaser. The phaser then changes camshaft position relative to the crankshaft, and CMP feedback tells the PCM how the cam actually moved.
This creates a command-and-response chain: electrical command, solenoid and oil-control-valve movement, oil supply and pressure, phaser movement, CMP feedback, and crank/cam comparison. A failure anywhere in that chain can prevent actual cam position from matching the model.
P0013 belongs mainly to the electrical command layer. P0016 belongs to the resulting relationship layer. P0335 and P0340 belong mainly to the position-input layers. Codes from more than one layer can appear together, so code priority and shared-cause checks matter.
What the four linked DTCs are telling you
| DTC | Diagnostic category | What it directs you to prove |
|---|---|---|
| P0013 | VCT actuator-control circuit open or state mismatch | Whether the control and ground paths, connector and terminals, harness, solenoid, and controller-side command are electrically sound before a component is condemned |
| P0016 | Crankshaft/camshaft timing misalignment or correlation | Whether recognized CKP and CMP positions remain correctly related, then whether oil condition and pressure, VCT control, phaser or target condition, or mechanical timing explains the deviation |
| P0335 | CKP signal implausible | Whether the shared reference, signal and ground paths, connector, sensor mounting, CKP sensor, and crank target produce a credible position pattern |
| P0340 | CMP signal absent or implausible | Whether the shared reference, signal and ground paths, connector, sensor mounting, CMP sensor, cam target, and synchronization conditions produce a credible cam pattern |
P0013 does not automatically mean “replace the VCT solenoid.” P0016 does not automatically mean “replace the timing chain.” P0335 and P0340 do not automatically mean “replace the sensor.” Classify the failed behavior first, then make the next test prove one branch.
What the driver or technician may notice
Possible observations include:
- a malfunction indicator lamp with little immediate change in drivability;
- extended cranking, a no-start, or a stall when position synchronization is unreliable;
- rough idle, hesitation, reduced response, or related misfire symptoms when cam timing is affected;
- a fault that appears after oil service, sensor work, valvetrain work, timing-system repair, flywheel work, or programming;
- an intermittent code that changes with temperature, engine speed, vibration, harness position, or connector movement;
- related VCT, oil-pressure, reference-voltage, position-signal, or misfire DTCs.
These observations do not identify the failed branch. Preserve the complete scan and operating record before clearing codes.
Common failure categories
Shared reference, signal, ground, connector, or harness fault
CKP and CMP diagnosis begins with electrical integrity. An open, short, excessive resistance, weak ground, spread terminal, corrosion, water intrusion, heat damage, or harness rub can remove or distort a position pattern. A shared reference fault can affect more than one sensor and generate several DTCs.
Inspect routing, locks, seals, terminal fit, and recent service areas. Use terminal-safe methods and the exact circuit procedure. Do not force probes into protected control-module terminals or apply power to a controlled circuit unless current service information specifically permits it.
Sensor mounting, debris, air gap, or rotating-target fault
A good sensor cannot produce a trustworthy pattern if it is loose, incorrectly seated, contaminated, too far from its target, or reading a damaged, shifted, loose, or debris-covered target. The pattern may drop out only at a certain speed, temperature, or shaft position.
Inspect mounting and targets only with the approved access and engine-rotation procedure. A new sensor cannot correct damaged target hardware or an installation problem.
VCT control circuit, solenoid, or oil-control-valve fault
P0013 can result from a failed control or ground path, poor connection, or a solenoid that does not electrically or mechanically respond as commanded. Deposits or sticking in the oil-control portion can affect movement even when basic circuit checks pass.
Separate electrical command from hydraulic and mechanical response. Prove terminal contact, circuit load capability, and the solenoid branch before considering controller replacement.
Oil condition, filter, supply, or pressure fault
The phaser depends on clean oil of the correct specification reaching it at stable pressure. Low level, unsuitable viscosity, contamination, aeration, an incorrect filter, restricted flow, sludge, pump or pickup problems, and other oiling faults can make cam movement slow, incomplete, or unstable.
Verify oil level, condition, service history, filter application, and directed pressure evidence before condemning a phaser or opening the timing drive. Electrical command, oil supply, valve movement, and mechanical response are different diagnostic layers.
Phaser, chain, sprocket, guide, or tensioner fault
A phaser can fail to move to or maintain the commanded position. Incorrect chain or sprocket alignment, chain wear, a damaged guide or tensioner, a target problem, or an assembly error can shift the physical relationship.
This branch becomes credible after the signals are recognized and stable, related electrical faults are resolved, oil and VCT conditions are known, and correlation evidence remains. Do not begin with engine disassembly only because P0016 is stored.
Recent-service or relearn problem
A connector left loose, incorrect oil or filter, disturbed target, sensor installation error, misassembled timing hardware, or omitted relearn can create a post-repair fault. Review the timeline before treating the code as an unrelated new failure.
A relearn updates valid relationship information; it cannot repair a noisy signal, damaged target, low oil pressure, sticking valve, or incorrect mechanical alignment.
Controller or software is suspected too early
PCM involvement is possible but belongs late in the diagnostic tree. Applicable service information and software updates, power and ground integrity, external circuits, terminals, signals, sensor and target condition, oil/VCT response, learned information, and mechanical timing must be evaluated first.
A practical system-first diagnostic strategy
Step 1: Confirm applicability and preserve evidence
Verify the VIN, model year, 5.7-liter configuration, calibration, and current service information. Save the complete module scan, active/pending/stored DTCs, failure records, CKP/CMP synchronization or activity, commanded and actual cam data, oil information, and recent repair history before clearing anything.
Step 2: Classify the primary fault
P0335 and P0340 direct you first toward signal integrity. P0013 directs you toward the VCT control circuit and solenoid command path. P0016 requires recognized position information and directs you toward crank/cam relationship, oil/VCT response, target condition, and mechanical timing. Decide which layer failed before choosing tools or parts.
Step 3: Resolve shared and prerequisite faults first
Follow the current code-priority instructions. Diagnose active reference-voltage, power, ground, position-signal, or VCT electrical faults before relying on a correlation verdict. One shared circuit or connection can produce several codes and invalidate downstream conclusions.
Step 4: Inspect basics and recent service
Check battery and cranking performance when starting or synchronization is affected. Verify specified oil level, condition, viscosity, filter application, and pressure when directed. Ask whether the concern began after oil, sensor, harness, flywheel, valvetrain, timing, or programming work.
Step 5: Prove electrical integrity under the right conditions
Inspect CKP, CMP, and VCT harnesses and connectors, then isolate reference, signal, control, and ground paths with the exact procedure. Use load-capable or voltage-drop methods where specified rather than relying only on unloaded readings. Check terminal fit and intermittents while protecting the circuit.
Step 6: Prove position-signal quality and target condition
Use scan data to determine whether the PCM recognizes CKP and CMP activity. When needed, use the applicable signal or waveform test to look for dropout, noise, irregular spacing, or timing drift. Correlate the symptom with temperature, vibration, engine speed, and harness movement. Inspect mounting and targets when the evidence supports that branch.
Step 7: Separate VCT command from VCT response
When inputs and circuits are credible, compare commanded cam movement with actual feedback under valid conditions. If the command is correct but movement is not, follow the oil supply, oil-control valve, phaser, and mechanical branches in the current service-information order.
Step 8: Inspect mechanical timing only when supported
Evaluate chain and sprocket alignment, guide and tensioner condition, phaser and target condition, and related mechanical fitment only after earlier evidence supports this branch. Use the exact alignment tools, holding procedures, fasteners, sealing instructions, lubrication steps, and torque specifications for the truck.
Step 9: Perform required learning and verification
After specified position-sensor, target, flywheel, valvetrain, timing-drive, or related work, complete the required crank/cam learning procedure with every prerequisite satisfied. Reproduce the original operating conditions, confirm stable position recognition and cam response, rerun the relevant monitor, and verify that no pending or confirmed DTC returns. Clearing the warning lamp is not a verified repair.
Safety before testing or relearning
Position and VCT tests may require cranking, a running engine, or controlled changes in engine speed. Work in a ventilated area, set the parking brake, secure the truck against movement, and keep hands, clothing, tools, leads, and loose objects away from belts, pulleys, fans, and hot exhaust parts. Do not stand in front of or behind an unsecured truck during a commanded procedure.
Prevent unexpected cranking or starting before touching sensors, targets, timing hardware, or control-module connectors. Follow current power-down and battery procedures, use the specified engine-rotation method, and support removed components correctly. Stop a functional test or relearn if the engine behaves abnormally or a prerequisite is not satisfied.
Match the repair to the proven failure
The supported repair may involve terminal or wiring repair, connector service, correcting sensor or solenoid installation, replacing a proved CKP or CMP sensor, repairing a rotating target, replacing a proved VCT solenoid, restoring correct oil and filter condition, repairing an oil-pressure or oil-flow problem, servicing a phaser, correcting chain/guide/tensioner damage or mechanical alignment, updating applicable software, or completing the required relearn. PCM work belongs at the end of the applicable diagnostic path.
Mechanical timing repairs are precision work. Current service information for the exact truck controls alignment, holding, one-time-use parts, torque, sealing, lubrication, programming, learning, and final verification.
Final takeaway
On the 2019-2024 Ram 1500 Classic 5.7L HEMI Gas, timing diagnosis is a comparison among electrical command, oil-supported phaser movement, CKP/CMP signal quality, learned crank/cam relationship, and mechanical alignment. P0335 and P0340 ask whether the PCM receives credible position patterns. P0013 asks whether the VCT control circuit behaves as commanded. P0016 asks whether recognized crank and cam positions remain correctly related.
Preserve evidence, classify the failed layer, resolve shared electrical faults, verify oil and VCT response, prove signal and target quality, and inspect mechanical timing only when the evidence points there. Complete required learning and rerun the monitor before calling the repair finished. The linked STEP guides provide model-specific educational paths; current service information for the exact truck controls specifications, commands, connectors, component locations, disassembly, and verification.
