Fix P0344: Mechanic’s solutions that WORKED

The code P0344: Camshaft Position Sensor Circuit Intermittent indicates an intermittent fault in the camshaft position sensor circuit. This issue is usually triggered by a malfunction in the sensor itself, its wiring, or related engine timing components. Given its critical role in engine management, addressing this fault is important for maintaining optimal engine performance.

P0344 quick overview

Meaning	P0344: Camshaft Position Sensor Circuit Intermittent.
Is it serious?	Yes, it can affect the engine’s performance and should be addressed promptly.
Possible causes	Faulty or failing camshaft position sensor Damaged or corroded sensor wiring and connectors Issues with the engine’s timing components Malfunctioning engine control module (ECM) Problems with related systems like Variable Valve Timing (VVT)
How to diagnose?	A faulty or failing camshaft position sensor Damaged or corroded sensor wiring and connectors Issues with the engine’s timing components Malfunctioning engine control module (ECM) Problems with related systems like Variable Valve Timing (VVT)

This error code means that there’s an intermittent problem with the sensor that helps your car’s computer understand the position of the camshaft. This sensor is crucial for your engine to work properly, as it affects the timing of fuel injection and ignition. If this sensor isn’t working right, it can cause your engine to run poorly or even prevent it from starting.

How to fix P0344 – learn from mechanics

I looked into P0344 service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.

Case #1: Dodge

Vehicle Information

• Make: Dodge
• Model: Neon SXT
• Year: 2003
• Engine: 2.0L

Issue + Repair History

• MIL Lamp on
• Initial Code: PO340 (CMP signal lost)
• Subsequent Code: PO344 (CMP signal erratic)
• Repair Attempt: Replaced CMP (Camshaft Position) Sensor

Other OBD2 Codes + Test Results

• No additional codes mentioned

Suggestions to Fix Issue

• Check connector pins for looseness
• Inspect the magnet on the back of the cam
• Examine wiring harness for damage or melting
• Verify crank sensor harness condition
• Check for spread terminals on CMP and CKP sensors
• Inspect pin from crank sprocket to camshaft
• Consider harness issues, especially shorting or melting
• Evaluate timing cover for noise, loose belt, or tensioner issues
• Replace both crank and cam sensors as a precaution
• Look into updated TSB for replacing Cam Sensor and wiring
• Check for oil in connector and wires
• Consider PCM flash update or replacement

Final Fix

• Replacing with OEM parts resolved the issue
• Key Finding: Aftermarket CAM DIFF pid read 5.2-6.0 degrees, while Chrysler CMP read 4.5-4.8 degrees, indicating a narrower margin for error with OEM parts.

Case #2: Chrysler

Vehicle Information

• Make: Chrysler
• Model: PT Cruiser Classic
• Year: 2005
• Engine: 2.4L

Issue + Repair History

• MIL Lamp on, vehicle cuts out
• Initial Code: P0340 (Cam Position Sensor Circuit)
• Subsequent Code: P0344 (Cam Position Sensor Circuit Intermittent)
• Replaced Cam Sensor with aftermarket part

Other OBD2 Codes + Test Results

• No additional codes mentioned

Suggestions to Fix Issue

• Consider the possibility of timing belt shift
• Check for wiring issues to the crank sensor connector in the harness
• Replace aftermarket cam sensor with a Mopar part
• Inspect the target magnet on the end of the camshaft
• Verify cam is not “walking”, altering sensor-magnet distance
• Scope pattern of CKP and CMP signals for waveform and sync
• Replace crank sensor along with cam sensor, using dealer parts
• Check and separate wiring at rear of engine below exhaust manifold

Final Fix

• Replacing the cam position sensor with another aftermarket unit temporarily resolved the issue
• Plans to install a Chrysler unit when possible

Case #3: Jeep

Vehicle Information

• Make: Jeep
• Model: Grand Cherokee Laredo
• Year: 2011
• Engine: 5.7L

Issue + Repair History

• Poor Idle Quality, MIL Lamp on
• Initial Codes: P0339, P0340
• Subsequent Code: P0344 (Intermittent CPS failure)
• Actions Taken: Replaced both cam and crank sensors with OE sensors, replaced wiring from cam sensor to PCM
• Notable: Issue only occurs when engine is hot and revving above 2000 RPM

Other OBD2 Codes + Test Results

• No additional codes mentioned

Suggestions to Fix Issue

• Check PCM for failure
• Inspect cam phasers and oil control solenoids for proper operation
• Ensure CMP sensor is properly tightened
• Confirm good oil pressure
• Scope signals at the PCM, not just at the sensors
• Consider VVT system influence on signal discrepancies
• Math channel on scope might help identify issues not visible in normal scoping

Final Fix

• Unplugging VVT system at left rear head prevented the fault
• Replaced cam sprocket, resolving the issue

Case #4: BMW

Vehicle Information

• Make: BMW
• Model: 330Ci
• Year: 2002
• Engine: 3.0L

Issue + Repair History

• No Start, MIL Lamp on
• Codes Initially Present: P0339, P0340
• Subsequent Code: PO344 (Cam Sensor A Circuit Bank 1 Intake)
• Replaced intake cam sensor, crank sensor, and spark plugs (which were fouled)
• Issue: Difficult to start when cold, requires multiple cranks

Other OBD2 Codes + Test Results

• No additional codes mentioned

Suggestions to Fix Issue

• Recheck spark plug application
• Inspect fuel injectors for leakage
• Check EWS module for security issues
• Evaluate fuel pressure, especially pump check valve
• Assess engine coolant temperature sensor
• Confirm good set of OE spark plugs
• Check compression and timing
• Consider recoding DME if cam sensor replaced on M54 engine
• Scope sensor on startup for any dropout
• Check for DME updates and OEM sensors only
• Investigate VANOS camshaft adjustment unit and camshaft timing
• Look for fuel pressure drops post shutdown

Final Fix

• Replacing with OEM cam sensor resolved the issue
• Initial replacement with aftermarket sensor proved inadequate

Case #5: Ford

Vehicle Information

• Make: Ford
• Model: F-250 XL
• Year: 1995
• Engine: 7.3L Power Stroke Diesel

Issue + Repair History

• No Start, Stall
• Code: P0344 (Cam Sensor Intermittent Failure)
• Repair Actions: Checked fuel pressure (30-70 psi fluctuating), bled air from fuel system multiple times

Other OBD2 Codes + Test Results

• No additional codes mentioned
• Fuel pressure fluctuated rapidly between 30 – 70 psi
• ICP pressure ranged from 0-782 when truck started

Suggestions to Fix Issue

• Possible injector O-rings issue
• Check fuel pressure again after removing air
• Likely bad fuel pump
• Normal for fuel pressure to fluctuate with a mechanical pump
• Check tachometer for steady reading (related to CMP signal)
• Possible bad injector O-rings, leading to oil in the fuel
• Inspect strainer cup beside fuel filter for deteriorating O-rings

Final Fix

• Replaced mechanical fuel pump, resolved starting issues

Common Advice	Diagnostic Step Description
Use OEM Parts	Replace sensors with original equipment manufacturer parts for reliability.
Check Fuel Pressure	Ensure fuel pressure is within the normal range; fluctuation may indicate issues.
Inspect Wiring and Connectors	Examine wiring harnesses and connectors for damage, looseness, or corrosion.
Scope Sensor Signals	Use an oscilloscope to monitor the waveform of sensors for irregularities.
Consider Related Systems	Evaluate systems that interact with the sensor, like VVT or fuel system components.
Bleed Air from Fuel System	Remove air from the fuel system, especially in diesel engines, to ensure proper fuel flow.
Monitor for Intermittent Failures	Be aware that intermittent sensor failures may not always show up in initial tests.