Fix P0349: Mechanic’s solutions that WORKED

The P0349 code indicates a problem with the camshaft position sensor “A” circuit in bank 2 of the engine, signaling an intermittent signal issue. This sensor plays a vital role in managing the engine’s timing and fuel injection by monitoring the speed and position of the camshaft.

An intermittent signal can lead to various performance issues, including difficulty starting, rough idling, and a possible decrease in fuel efficiency. Addressing this issue promptly is crucial for maintaining optimal engine performance and preventing potential damage.

P0349 quick overview

Meaning	P0349: Camshaft Position Sensor “A” Circuit Intermittent (Bank 2)
Is it serious?	Yes, because it can affect engine performance and, if left unaddressed, may lead to more significant engine issues.
Possible causes	– Faulty camshaft position sensor – Damaged or corroded sensor connector or wiring – Issues with the camshaft phaser – Poor electrical connections – Engine timing issues
How to diagnose?	Check for service bulletins related to the issue, as manufacturer updates may recommend specific repairs. Perform a wiggle test on the cam sensor connector to identify any intermittent connection issues. Check continuity and resistance in the wiring from the cam sensor to the PCM for potential high resistance. Verify oil pressure to ensure it’s within the proper range for engine operation. Inspect the camshaft phaser for signs of being stuck or malfunctioning without making noise. Consider replacing the camshaft sensor if testing indicates it is faulty. Inspect timing components like tensioners, guides, and chains for wear or failure.

How to fix P0349 – learn from mechanics

I looked into P0349 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: Ford

Vehicle information 2006 Ford Expedition King Ranch 5.4L

Issue + repair history

• MIL lamp on
• Trouble codes: P0345 – Cam sensor ckt bank 2, P0349 – Camshaft sensor signal intermittent bank 2
• Previous repair attempt: Customer replaced bank 2 cam sensor
• Immediate setting of trouble codes after startup
• Engine purchased at auction, no maintenance history known
• No noise or drivability issues observed

Other OBD2 Codes + Test Results

• OBD2 Code: P0345 – Cam sensor ckt bank 2
• OBD2 Code: P0349 – Camshaft sensor signal intermittent bank 2

Mechanic suggestions

• Check for service bulletins (TSB 06-19-12) recommending replacement of phaser solenoids
• Perform a wiggle test on the connector to cam sensor bank two, consider replacing with junkyard connector if necessary
• Check continuity for high resistance from cam signal to PCM
• Consider that the phaser may not necessarily be noisy and could be stuck in one position
• Verify oil pressure (should be 30 psi or better when warm), check for a bad new cam sensor or damaged wires

Final fix Replacement of both tensioners, all guides, chains, and timing chain tensioner for bank #2 collapsed and jumped a tooth.

Case #2: Chrysler

Vehicle information 2014 Chrysler 300 3.6L

Issue + repair history

• MIL lamp on
• Trouble code: P0349 – Camshaft position sensor circuit bank 2 sensor 1
• Previous repair attempt: Another shop replaced all lifters
• Engine idles okay
• Noisy lifters reported prior to repair
• Same shop removed camshafts to check for timing problems, found them to be okay
• Vehicle purchased at auction, no maintenance history known

Other OBD2 Codes + Test Results

• OBD2 Code: P0349 – Camshaft position sensor circuit bank 2 sensor 1

Mechanic suggestions

• Check for loose oil galley bolts in the front of the head
• Verify the integrity of the cam position target magnet at the rear of the camshaft, as it can be damaged during repair
• Ensure the oil galley bolts near the camshaft sprockets are present and torqued correctly
• Use a scope to compare the bank #1 to bank #2 CMP signals, they should look the same
• Verify circuit voltage values and focus on potential circuit issues rather than timing problems
• Consider the possibility of a damaged cam sensor tone wheel caused by magnetic tools during repair

Final fix A pulse wider than normal was found during waveform analysis, causing the cam signal to be out of alignment. No defects were found with the camshaft itself, but the signal was not correct. Adjustments made to correct the pulse width resolved the issue.

Case #3: Chevrolet

Vehicle information 1997 Chevrolet Commercial 5.7L

Issue + repair history

• Check engine light on
• Trouble code: P0102 – MAF Low Frequency
• MAF sensor readings not present despite voltage input
• Replaced MAF sensor with OEM part, same readings persisted
• Engine stalling when airflow obstructed over MAF sensor
• Checked power going into sensor: 5.10 volts, return side signal: 0.032 volts
• Replaced MAF sensor, no change in readings
• Checked MAF ground, found no issues
• Checked power to MAF sensor, found 5.10 volts
• Receiving numerous replies but unable to resolve issue
• Checked fuse for MAF sensor and heated oxygen sensors
• Discovered 15 Amp Eng fuse powering MAF sensor was removed, causing lack of power to the sensor
• Realized MAF sensor requires ignition voltage to operate properly

Other OBD2 Codes + Test Results

• OBD2 Codes: P0102 – MAF Low Frequency, P0349 – CMP Cam Sensor Circuit

Mechanic suggestions

• Check MAF ground and ensure it’s functioning properly
• Investigate the ground circuit for any issues
• Consider the computer as a potential source of the problem
• Verify the frequency mode of the MAF sensor and inspect the cam sensor circuit

Final fix The issue was traced to the 15 Amp Eng fuse that powers the MAF sensor and heated oxygen sensors. The absence of this fuse resulted in a lack of power to the MAF sensor, causing the low frequency readings. Once the fuse was replaced, the MAF sensor began functioning properly.

Diagnostic Step	Explanation
Check for service bulletins (TSB)	Identifies manufacturer-recommended fixes for known issues.
Perform a wiggle test on connectors	Helps uncover intermittent electrical connections.
Check wiring continuity and resistance	Ensures electrical signals travel without excessive resistance.
Verify oil pressure is adequate	Low oil pressure can affect camshaft operation and sensor performance.
Inspect the camshaft phaser and timing components	Ensures mechanical parts related to timing are functioning correctly.
Use a scope to compare signals	Helps diagnose signal integrity issues by comparing with a known good waveform.
Replace faulty components as needed	Addresses any identified failures in sensors, wiring, or mechanical parts.

The P0349 code signals an intermittent problem that requires careful diagnosis to identify and correct the underlying issue. As seen in the service cases of a Ford Expedition, Chrysler 300, and a Chevrolet Commercial vehicle, solutions can vary from electrical repairs to mechanical timing adjustments. Each case highlights the importance of thorough testing and inspection to resolve the intermittent signal issue properly. Addressing this code promptly can help maintain engine performance and prevent further damage.