TEST 4: Testing The 1° POS Signal
For our last test we're gonna' make sure that the camshaft position sensor is producing a 1° POS signal. And we'll use the LED light to confirm its presence.
The wire that we're gonna' test is the wire labeled with the number 4 in the photo above.
On the Frontier and Xterra, this is the light green (LT GRN) wire of the distributor's 6-wire connector.
On the Quest and Villager, this wire is the orange (ORG) wire of the distributor's 6-wire electrical connector.
On the QX-4 and Pathfinder, this is the blue (BLU) wire of the distributor's 6-wire connector.
If the camshaft position sensor is producing the 1° POS signal, then the LED light will flash ON and OFF and it'll flash ON and OFF very rapidly.
When you tested the 120° REF signal with the LED light, you were able to see distinct on/off pulses of light from the LED light. The 1° POS signal pulses so fast that you won't see distinct on/off flashes of the LED light.
What you'll see is the LED light flashing so rapidly that it'll seem as if the LED light is just dimming. This is normal.
If the camshaft position sensor is bad and not producing a 1° POS signal, the LED light will not flash (stay OFF) the whole time you're turning the engine by hand.
NOTE 1: The distributor must remain connected to its 6-wire electrical connector for this test to function. You'll need to use a wire piercing probe to connect the LED light to the signal wire. You can see an example of this tool here: Wire Piercing Probe.
NOTE 2: This test requires that you turn the engine by hand (with the appropriate tools). Don't use the starter motor to test for the cam signal.
IMPORTANT: The fuel pump fuse must be removed before attempting this test. You can find the location of the fuel pump fuse here: Fuel Pump Fuse Location
OK, these are the test steps:
Locate the wire labeled with the number 4, in the photo above.
Connect the red lead of the LED light to the wire labeled with the number 4.
IMPORTANT: The distributor's connector must remain connected.
Connect the black lead of the LED light to the battery negative (-) terminal.
Turn the key ON but don't crank the engine.
The LED light should be off. If the LED light is ON at this point, the the camshaft position sensor is bad.
Slowly turn the engine by hand using the appropriate tools when you have everything set up.
Remember, the fuel pump fuse must be removed before attempting this test.
The LED light should flash ON and OFF as you turn the engine by hand.
NOTE: The slower you turn the crankshaft pulley, the better you'll be able to see the LED light flashing ON and OFF.
Let's analyze your test result:
CASE 1: The LED light flashed ON and OFF as you turned the crankshaft pulley. This is the correct test result and confirms that the 1° POS signal is present.
CASE 2: The LED light came ON as soon as turned the key ON and without turning the crankshaft pulley. This test result tells you that the camshaft position sensor is bad.
CASE 3: The LED light DID NOT flash ON and OFF as you turned the crankshaft pulley. This test result tells you that the camshaft position sensor is not producing the 1° POS signal.
You can conclude that the camshaft position sensor is bad if you have confirmed that:
- The ignition coil does not spark.
- The camshaft position sensor is getting 10 to 12 Volts.
- The camshaft position sensor has Ground.
- The camshaft position sensor is not creating a 1° POS signal.
Since the camshaft position sensor isn't sold separately, you'll need to replace the distributor.
Where To Buy The Distributor And Save
The distributor on your 3.3L V6 Nissan Frontier, Pathfinder, or Xterra isn't an inexpensive component. Check out the following links and compare prices, I think they'll save you a few bucks:
The distributors in the links above fit the following vehicles:
- 3.3L Nissan Frontier: 1999, 2000, 2001, 2002, 2003, 2004.
- 3.3L Nissan Pathfinder: 1996, 1997, 1998, 1999, 2000.
- 3.3L Nissan Xterra: 2000, 2001, 2002, 2003, 2004.
More Nissan 3.3L V6 Tutorials
If this tutorial was helpful, check out the others I've written for the 3.3L V6 equipped Nissan vehicles. You can find a complete list of tutorials here: Nissan 3.3L Index Of Articles.
Here's a sample of the tutorials you'll find there:
- Mass Air Flow (MAF) Sensor Test 3.3L Frontier, Quest, Pathfinder, XTerra.
- Power Transistor Test And Ignition Coil Test 3.3L Nissan (1996-2004).
- Ignition System Wiring Diagram (1999-2004 3.3L Frontier And Xterra).
- How To Test For A Blown Head Gasket (3.3L V6 Frontier, Pathfinder, Xterra).
If this info really saved the day, buy me a beer!