How to Replace the Camshaft Position Sensor on a Jeep Wrangler JK

Chris

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Edwin H. Hall was an American physicist, who in 1879 discovered that he could accurately change and measure voltage on a conductor by passing it through a perpendicular magnetic field. Today his "Hall effect" magnetic sensing is used in your Wrangler's camshaft position sensor and crankshaft position sensor to precisely control engine timing. However, several Wrangler Technical Service Bulletins have been released for camshaft position sensors that cause long engine start cranking times and continued cranking for several seconds after the key is released. Also, when the camshaft position sensor goes bad, it will throw code P0340: "Camshaft position signal is not detected by the Power Control Module (PCM)."

The 2007 to 2011 Wrangler 3.8L uses camshaft position sensor 5149078AD and the 2012 to 2016 Wrangler 3.6L Pentastar uses camshaft position sensor 5149141AF. This DIY will cover the 3.8L procedure first, followed by the 3.6L Pentastar procedure.

Note
To insure correct parts, always order parts by your specific Vehicle Identification Number (VIN).

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Materials Needed
  • Camshaft position sensor
  • 10mm wrench
  • T30 Torx driver
  • Mechanic's gloves
  • Clean rags
Before beginning, disconnect the negative (black) battery cable. Also, always work when the engine is cold.
  1. Write down any radio or navigation security codes.
  2. Use a 10mm wrench to remove the negative battery cable.
  3. Ensure the negative cable cannot contact the negative or positive terminals.
1-WranglerJK-DisconnectNegativeBatteryCable-119655.jpg

Figure 1. Disconnect negative battery cable.




3.8L Camshaft Position Sensor Replacement

Step 1 – Camshaft position sensor familiarization
The sensor for the 3.8L is Mopar part 5149078AD. It is also widely available on the aftermarket and the price varies from $35 to $65. The sensor body is sealed into the timing cover with an O-ring and is retained by one 10mm bolt.

-WranglerJK3-8L-CamPosSensorFamiliarization-119661.jpg

Figure 2. Camshaft position sensor familiarization.

Step 2 – Camshaft position sensor location
The sensor is located on the upper front of the engine. Follow the upper radiator hose back to the engine. Directly below that is the water pump. The sensor is just above the water pump and directly behind the accessory belt.

3-WranglerJK-CamPosSensorLocation-119676.jpg

Figure 3. Camshaft position sensor location.

Step 3 – Camshaft position sensor replacement
  1. Clean the sensor body and the area around it.
  2. Disconnect the electrical plug.
  3. Remove the 10mm bolt.
  4. Turn and pull on the sensor body to remove it.
  5. Check that the hole is clean and the old O-ring is removed.
  6. Lubricate the O-ring on the new sensor with motor oil. (If the new sensor has a paper spacer on the end, leave it in place.)
  7. Push in the new sensor and tighten the bolt.
  8. Connect the electrical plug.
  9. Reconnect the negative battery cable.
4-WranglerJK3-8L-CamPosSensorRemoval-119678.jpg

Figure 4. Camshaft position sensor removal.




3.6L Pentastar Camshaft Position Sensor Replacement

Step 1 – Engine cover removal
The sensor is under the engine cover. The engine cover is held by two ball-pins at the front and two hooks at the rear.
  1. Pull up on the front of the cover to release the ball-pins.
  2. Pull the cover forward to release the rear hooks.
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Figure 5. Engine cover removal.

Step 2 – Camshaft position sensor familiarization
On Oct 8, 2014, Chrysler released TSB 18-054-14 for cam position sensors that cause long engine crank times in 2014 Wranglers. The failed sensor is on Bank 1 (passenger's side cylinder head) and its serial number begins with "D." The replacement sensor for the 3.6L Pentastar is Mopar part 5149141AF, which replaces all previous versions. It is available on the aftermarket and the price varies $30 to $50.

-WranglerJK3-6L-CamPosSensorFamiliarization-119692.jpg

Figure 6. Camshaft position sensor familiarization.

Step 3 – Camshaft position sensor location
The sensor is located at the top-rear of the passenger's side valve cover. Look directly below the transmission dipstick. You may have to move some wires for a better view.

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Figure 7. Camshaft position sensor location.

Step 4 – Camshaft position sensor replacement
  1. Clean the sensor body and the area around it.
  2. Disconnect the electrical plug.
  3. Loosen the T30 Torx screw.
  4. Pull the sensor straight out, without turning it.
  5. Note the keyed shape of the sensor and push it straight in.
  6. Tighten the T30 Torx screw.
  7. Connect the electrical plug.
  8. Reinstall the engine cover.
  9. Allow the Wrangler to sit overnight with the negative battery cable disconnected.
  10. Connect the negative battery cable.
  11. Start the engine and allow it to idle for 15 minutes for the PCM to do crank/cam re-learn.
8-WranglerJK3-6-CamPosSensorRemoval-119697.jpg

Figure 8. Camshaft position sensor removal.

Pro Tip
The TSB 18-054-14 calls for the PCM crank/cam re-learn to be done on the dealership computer. However, many Wrangler owners report that the re-learn can be done by leaving the battery disconnected overnight.