Nissan Altima Crankshaft Position & Camshaft Sensor Replacement Guide
Pictures & instructions on how to replace the crankshaft position sensor & camshaft sensor in a L31 2002 to 2006 Nissan Altima.
Driver's Side, Below Throttle Body
Camshaft Sensor Location
Driver's Side, Rear Side of Engine
Crankshaft Position Sensor Location
Broken Wire Connector
This guide covers the replacement of both the camshaft and crankshaft position sensors since they are both identical.
Owners of other 3rd generation 2002, 2003, 2004, 2005 & 2006 Altima sedans should find these DIY instructions to be helpful.
In the above row of photos you can see the location of the camshaft sensor on the driver's side of the engine and the crankshaft position sensor is down on the back side of the engine (best seen from under the car & removed from above).
To replace either sensor you will need a 10mm metric bolt and a ratchet wrench. Don't forget the rubber o-ring.
Now for our saga. On a holiday weekend we discovered that the 2.5L inline 4 cylinder engine in the L31 generation 2002 Nissan Altima was leaking oil.
Upon inspection of the motor, my brother pinpointed the source of the oil leak to be the crankshaft position sensor.
The reason that the engine was leaking oil was that a careless auto mechanic neglected to install an o-ring on to the sensor during the car's 60,000 mile service.
When replacing either sensor, be sure to inspect the rubber o-ring and verify that it is actually on the sensor!
The mechanic also must have removed the wire harness connector with a screwdriver because it was practically falling apart.
A few compatible replacement camshaft position sensors with their part numbers include the following: OEM 96239, Standard Motor Products PC464, Nissan 23731-6N21A, Dorman 530-010 and Delphi SS10818.
Some replacement crankshaft position sensors with their part numbers are as follows: Nissan 23731-6N21A, Wells SU6364, Standard Motor Products PC464T, Hitachi W0133-1796511-HIT and Delphi SS10816.
Broken Harness Connector
Crankshaft Position Sensor
Engine Camshaft Sensor
Broken Air Box Tab
Camshaft Sensor Removed Besides destroying the wire connector & forgetting the o-ring, the thoughtless "automotive repair technician" also broke a retaining tab on the air box cover, crushed the air filter with his elbow, and neglected to replace a vacuum hose's clamp.
Camshaft & Crankshaft Sensors
Connector From Junkyard We needed to get this car running today and the only option was to visit a wrecked automobile parts recycling center, a.k.a. a junkyard.
Luckily the junkyard had a totaled 2006 Nissan Altima with the engine wiring still intact.
After we cut off the camshaft position sensor wire harness connector, all we had to do was splice it up to the '02 Altima with butt wire connectors.
If you don't have a junkyard in your area, I recommend buying the OEM Nissan 23731-6N21Acamshaft sensor and also the Nissan 23731-6N21Acrankshaft sensor.
Sensor With Rubber O-Ring
Butt Wire Connectors
Wire Butt Connectors Crimped For the best electrical connection, I recommend using crimp connectors.
If necessary, you could also just twist the wires together, wrap them in electrical tape and use cable ties to secure the tape.
10MM Sensor Bolts
Attaching New Connector
Protective Wire Loom
Connector Replacement Complete
Camshaft Sensor Inserted
10 Millimeter Bolt Secured
Altima Air Box & Air Intake Tube