TEST 4: Testing The 1° POS Signal

Testing The 1° POS Signal. How To Test The Crank Angle Sensor (1990, 1991, 1992, 1993, 1994, 1995, 1996 2.4L Nissan D21 Pickup, Pickup, 240SX)

So far your test results have confirmed that:

  1. The crank angle sensor is getting 10 to 12 Volts.
  2. The crank angle sensor has Ground.
  3. The crank angle sensor is producing a 180° REF signal.

For our last test we're gonna' check for the presence of the 1° POS signal as the engine is turned by hand once again.

The wire that we're gonna' connect the LED light to is the green with black stripe (GRN/BLK) wire of the distributor's 4-wire connector (see photo above).

Before we start, let me tell you that you won't be able to see distinct ON/OFF flashes of light from the LED when testing the 1° POS signal (if the sensor is producing the 1° POS signal).

This is due to the fact that the 1° POS signal is produced 180 times each revolution of the distributor shaft. You were able to see distinct ON/OFF pulses of light from the LED when testing the 180° REF signal because it's produced only 4 times per distributor shaft rotation.

If the 1° POS signal is present in the GRN/BLK wire, the LED will flash so fast (as you slowly turn the crankshaft pulley) that you'll usually just see it turn on and produce a dim light. This is normal.

If the 1° POS signal IS NOT present, then the LED light will not light up at all as you turn the crankshaft pulley by hand.

NOTE: The distributor must remain connected to its 4-wire electrical connector for this test to function. You'll need to use a back probe or a wire piercing probe to connect the LED light to the GRN/BLK wire. You can see an example of this tool here: Wire Piercing Probe.

IMPORTANT: As a safety precaution, remove the fuel pump fuse before starting this test.

OK, these are the test steps:

  1. 1

    Locate the GRN/BLK wire of the engine wiring harness connector (see photo above).

  2. 2

    Connect the red lead of the LED light to the GRN/BLK wire using the appropriate tools.

    IMPORTANT: The distributor must remain connected to the engine wiring harness connector to test the 1° POS signal.

  3. 3

    Connect the black lead of the LED light to the battery negative (-) terminal.

  4. 4

    Turn the key ON but don't crank the engine.

  5. 5

    The LED light should be OFF. If the LED light is ON at this point, the the crank angle sensor is bad.

  6. 6

    Slowly turn the engine by hand using the appropriate tools on the crankshaft pulley.

    As a safety precaution the fuel pump fuse should be removed before attempting this test.

  7. 7

    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.

You can conclude that the crank angle sensor is functioning correctly if you have:

  1. Confirmed that the crank angle sensor is getting 10 to 12 Volts.
  2. Confirmed that the crank angle sensor has Ground.
  3. Confirmed that the crank angle sensor is producing a 180° REF signal.
  4. Confirmed that the crank angle sensor is producing a 1° POS signal.

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 crank angle 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 crank angle sensor is not producing the 1° POS signal.

You can conclude that the crank angle sensor is bad if you have confirmed that:

  1. The ignition coil does not spark.
  2. The crank angle sensor is getting 10 to 12 Volts.
  3. The crank angle sensor has Ground.
  4. The crank angle sensor is creating a 180° REF signal.
  5. The crank angle sensor is not creating a 1° POS signal.

More 2.4L Nissan Pickup Tutorials

You can find a complete list of 2.4L Nissan tutorials in this index:

  1. Nissan 2.4L Index Of Articles.

Here's a small sample of the tutorials you'll find in the index:

  1. How To Test The Throttle Position Sensor (2.4L Pick Up, Frontier, Xterra).
  2. Frontier, XTerra MAF Sensor Test P0100: Mass Air Flow (MAF) Circuit Malfunction.
  3. Mass Air Flow (MAF) Sensor Test 2.4L Nissan D21 Hard Body (1990-1995).
  4. How To Test The Idle Switch (2.4L Pick Up, Frontier, Xterra).
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Nissan Vehicles:

  • D21 Pickup 2.4L
    • 1990, 1991, 1992, 1993, 1994
  • Pickup 2.4L
    • 1995, 1996
  • 240SX 2.4L
    • 1989, 1990