P0365 on 2014-2018 Ram 2500: Camshaft Sensor 'B' Circuit Causes and Fixes

What's Unique About the 2014-2018 Ram 2500

For this generation of Ram trucks, the manufacturer issued a Technical Service Bulletin (TSB #05149141A) covering code P0365 and other related cam sensor faults. 🎬 Watch: Understanding the causes and fixes for code P0365. The TSB instructs technicians to contact a specific factory representative before replacing the sensor and to send Freeze Frame and Cam/Crank Sync Event Monitor data to an FCA engineer. This strongly implies that a simple sensor swap may not be the correct fix and that more complex issues, such as wiring, PCM software, or other intermittent problems, are known to occur. This makes it critical for owners to diagnose the entire circuit rather than immediately assuming the sensor has failed.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• Check Engine Light is on
• Engine is difficult to start or cranks but won't start
• Rough idling or stalling
• Poor acceleration and loss of engine power
• Engine misfiring
• Vehicle enters 'limp mode' with reduced power
• Traction control light may illuminate simultaneously

Most Likely Causes

1. Faulty Camshaft Position Sensor 🔴 High Probability → Shop Engine Camshaft Position Sensor Sensors are electronic components exposed to extreme heat cycles and engine vibrations, which can lead to internal failure over time. Oil leaks from valve covers can also seep into the sensor's connector, causing damage.
   How to confirm: After verifying the wiring is intact, the easiest way to test is to swap the suspect sensor with an identical one from another position (e.g., the intake sensor or the sensor from the other bank on V8s) and see if the fault code follows the sensor. A multimeter can also be used to test the sensor's internal resistance against manufacturer specifications.
   Typical fix: Replace the Bank 1 exhaust camshaft position sensor. For Hemi engines, this is on the front of the engine block, under the alternator. 🎬 See this walkthrough for replacing the Hemi cam sensor. For the 6.7L Cummins, the single cam sensor is on the driver's side of the block, below the injection pump, and 🎬 Watch: Step-by-step 6.7L Cummins cam sensor replacement guide. may require removing the PCM for access. A cam/crank relearn procedure with a capable scan tool may be required after replacement.
   Est. part cost: $25-$100
2. Wiring Harness or Connector Issue 🟡 Medium Probability The engine wiring harness is exposed to significant heat and vibration, which can lead to chafed or broken wires, especially where the harness may rub against the engine block or other components. A specific chafe point has been noted on some Ram trucks near the transmission bell housing where the harness passes a metal grounding strap.
   How to confirm: Visually inspect the sensor's wiring harness for any signs of melting, chafing, or corrosion. Check the connector for a secure fit and clean pins. Use a multimeter to test for the 5-volt reference signal, proper ground, and signal continuity between the sensor connector and the PCM.
   Typical fix: Repair the damaged section of the wiring harness or replace the connector pigtail. Secure the harness away from sharp edges or heat sources to prevent future damage.
   Est. part cost: $15-$50 for a pigtail
3. Weak Battery or Charging System Issue ⚪ Low Probability → Shop Vehicle Battery The PCM is sensitive to system voltage. A weak battery or failing alternator can cause voltage drops during cranking, which may trigger spurious sensor circuit codes. This can sometimes be accompanied by other electrical-related codes like U1424.
   How to confirm: Test the battery voltage with a multimeter; it should be above 12.4V with the engine off. Have the battery and alternator tested under load at an auto parts store.
   Typical fix: Replace the weak battery or faulty alternator.
   Est. part cost: $150-$400

Rare But Worth Checking

• Powertrain Control Module (PCM) Fault: While rare, a failing PCM can cause a variety of incorrect sensor codes. The existence of TSB #05149141A suggests that Chrysler was investigating issues beyond simple sensor or wiring failures, which could include the PCM itself. This should be considered a last resort after all other possibilities are exhausted. A PCM software update may also be a potential fix for false codes, as seen in similar TSBs for other models.
• Timing Chain or Phaser Issue: → Shop Engine Timing Chain If the timing chain has stretched or a cam phaser is malfunctioning, the camshaft's position may not correlate correctly with the crankshaft's position, leading the PCM to flag a sensor circuit fault. This is a more serious mechanical issue and is often accompanied by rattling noises from the front of the engine, especially on startup.

Diagnosis Steps

1. Read all active and pending codes with an OBD-II scanner. Note the freeze frame data, which is critical information if TSB #05149141A needs to be followed.
2. Check the engine oil level and condition. Low or dirty oil can affect VVT system performance, which can indirectly trigger cam sensor codes.
3. Perform a detailed visual inspection of the Bank 1 exhaust camshaft sensor, its connector, and the wiring harness. For Hemi engines, this is on the front of the block. For Cummins engines, it's on the driver's side. Look for loose connections, oil contamination, or any signs of damage like melting or chafing.
4. With the engine running, carefully wiggle the wiring harness and connector to see if it causes the engine to stumble or the code to set, indicating an intermittent connection.
5. Use a multimeter to verify that the sensor connector has the correct 5V reference voltage and a good ground connection from the PCM.
6. If possible, use an oscilloscope to check the sensor's signal pattern against a known-good waveform. This is the most definitive way to confirm sensor functionality.
7. If wiring and power are good, consider swapping the sensor with an identical one from another location (on V8s) to see if the code follows the sensor. If it does, the sensor is faulty.
8. If the code remains after swapping, the issue is likely in the wiring or, in rare cases, the PCM.

Parts You'll Likely Need

• Camshaft Position Sensor (OEM #5149054AC) — This is the most frequently replaced component to resolve a P0365 code after wiring issues have been ruled out. This part number is applicable to the 5.7L and 6.4L Hemi engines and supersedes part number 5149054AB.
  Trusted brands: Mopar, Bosch, NTK
  OEM price range: $50-$100
  Aftermarket price range: $25-$75

Related Codes That Often Appear With This One

• P0369 — This code indicates an intermittent signal from the same sensor (Camshaft Position Sensor 'B' Circuit Intermittent), often pointing to a wiring or connection issue rather than a completely failed sensor.
• P0340 — This code is for the Bank 1 intake ('A') camshaft sensor. If both appear together, it could suggest a shared wiring problem (power or ground) or a larger mechanical timing issue on Bank 1.
• U1424 — This code for 'Implausible Engine Torque Signal' can appear with sensor codes like P0365 when a significant electrical fault in the harness or PCM causes multiple modules to report bad data. Owners have reported this combination when experiencing limp mode.

Technical Service Bulletins (TSBs) & Recalls

• 05149141A: Instructs technicians to contact a factory representative and provide freeze frame data before replacing a camshaft position sensor for P0365 and other related codes, suggesting a known complex issue.

Platform-Specific Known Issues

• A known Technical Service Bulletin (TSB #05149141A) was issued for this and other camshaft position sensor codes. It advises technicians to contact a specific factory engineer and provide diagnostic data before replacing the sensor, indicating that the root cause may be more complex than a simple part failure.
• For the 6.7L Cummins, accessing the single cam sensor is notoriously tight. It is located on the driver's side of the block, and mechanics often need to unbolt and move the PCM (four 10mm bolts) to gain enough clearance to remove the sensor's 5mm hex bolt.
• On Hemi V8 engines, the sensor is located on the front timing cover, below the alternator, making it relatively easy to access with a 10mm socket once the engine cover is removed.

Mechanic-Grade Diagnostic Values

• Camshaft Position Sensor 5-Volt Supply — expected: 4.5 - 5.2 Volts with key on, engine off.. Failure: Voltage below 4.5V or absent points to a wiring or PCM issue, not the sensor.
• Camshaft Position Sensor Ground Circuit Resistance — expected: Below 5.0 Ohms between the ground pin at the sensor connector and the corresponding pin at the PCM connector.. Failure: Resistance above 5.0 Ohms indicates an open or high resistance in the ground circuit (K900 on Hemi).
• Camshaft Position Sensor Signal Circuit Resistance — expected: Below 5.0 Ohms between the signal pin at the sensor connector and the corresponding pin at the PCM connector.. Failure: Resistance above 5.0 Ohms indicates an open or high resistance in the signal circuit (K441 on Hemi).
• Camshaft Position Sensor Signal Waveform — expected: A digital square wave switching between approximately 0V and 5V when viewed on an oscilloscope while the engine is cranking or running.. Failure: An absent, erratic, or misshapen waveform indicates a faulty sensor or a problem with the reluctor wheel.

Scan Tool Commands That Help

• Witech, Appcar DiagFCA, or other professional scan tools: Cam/Crank Relearn (or Cam/Crank Sync) — This procedure is required after replacing the camshaft or crankshaft position sensor, or after performing major engine work like timing chain replacement. It allows the PCM to learn the new sensor's specific signal characteristics. Failure to perform this can result in persistent running issues, rough idle, or other codes even with a good part. The engine coolant temperature must typically be above 158°F (70°C) to initiate the procedure.

Wiring & Ground Locations

• Hemi V8 Sensor Circuits — Wiring harness between the camshaft position sensor and the PCM.. Technicians must test specific circuits for continuity and shorts. These are the (K856) 5-volt Supply, (K900) Sensor Ground, and (K441) CMP Signal circuits. Testing these circuits by name helps isolate the fault between the sensor, harness, and PCM.
• 6.7L Cummins Cam Sensor Connector — On the driver's side of the engine block, below the CP3 injection pump.. Knowing the pinout is essential for testing. Pin 1 is the 5-volt supply, Pin 2 is the ground, and Pin 3 is the signal wire. Correctly identifying these pins is the first step in diagnosing the circuit.

Real Owner Repair Stories

• Reddit user in r/AskMechanics (2016 Ram 1500 3.6L V6 with 160k miles) — Randomly entering limp mode with Check Engine Light and disabled traction control. Codes P0365, U1424, and P1DD2 were present.
  ❌ Tried (didn't work) Replacing only one camshaft position sensor initially.
  ✅ What actually fixed it The issue was resolved only after replacing the *second* camshaft position sensor. The codes indicated a fault on one bank, but it turned out both original factory sensors had failed in close succession. After replacing the second sensor, the codes were cleared and did not return.