As you're probably already aware, when the crank angle sensor fails, the engine is not going to start due to a lack of spark and fuel injection.
In this tutorial I'm going to show you how to test the crank angle sensor with 4 simple tests. With your test results you'll be able to find out if it's defective or not.
NOTE: The crank angle sensor is known by several names: distributor pickup, crankshaft position (CKP) sensor, and camshaft position (CMP) sensor. To keep things simple, I'll be calling it the crank angle sensor throughout the tutorial.
Contents of this tutorial at a glance:
You can find this tutorial in Spanish here: Cómo Probar El Sensor De La Posición Del Cigüeñal (1990-1996 2.4L Nissan Pickup) (at: autotecnico-online.com).
This tutorial applies to the following vehicles:
- 2.4L Nissan D21 Pickup: 1990, 1991, 1992, 1993, 1994.
- 2.4L Nissan Pickup: 1995, 1996.
- 2.4L Nissan 240SX: 1989, 1990.
Important Tips And Suggestions
TIP 1: In this tutorial I'm going to show you how to test the crank angle sensor signals with an LED light. Since you'll be using an LED light, you'll need to turn the engine by hand. In other words, you cannot use the starter motor to crank the engine to perform TEST 3 and TEST 4.
If you'd like to see what LED light looks like, you can see an example here: The LED Light Test Tool And How To Make One.
TIP 2: The fuel system must be disabled before you do TEST 3 and TEST 4. You can easily do this by removing the fuel pump fuse.
TIP 3: Before testing the crank angle sensor, it's important that you first test for spark. If any of the four spark plug wires are sparking, then you can correctly conclude that the crank angle sensor is working correctly.
To be a bit more specific, when the crank angle sensor fails, you're not going to see spark at any of the spark plug wires because the ignition coil is not working.
If you haven't tested the ignition coil yet, start with that test first. You can find the ignition coil test here: How To Test The Ignition Coil 1992-1994 Nissan D21 Pickup.
How Does The Crank Angle Sensor Work?
The fuel injection computer uses the crank angle sensor to activate the power transistor. The power transistor in turn activates the ignition coil. Here's a very brief description of how it all works:
- The crank angle sensor is located inside the distributor.
- Now, when you turn the key and crank the engine (to start it), the crank angle sensor gets power thru' the black with white stripe (BLK/WHT) wire of the distributor's 4-wire connector.
- As the engine turns, the crank angle sensor starts to create two specific position signals that it sends directly to the computer. One signal is called the 1° POS signal and the other is called the 180° REF signal.
- When the computer gets these two position signals, it does its little song and dance and shoots an activation signal to the power transistor.
- When the power transistor gets its activation signal from the fuel injection computer, it now starts to switch the ignition coil's power ON and OFF. This ON/OFF action is what makes the ignition coil spark and is referred to as the switching signal.
When the crank angle sensor fails on your 2.4L Nissan Pickup (D21 and 240SX), the engine is not going to start due to a lack of spark.
You're also going to see a trouble code 11 registered in the fuel injection computer.
TEST 1: Making Sure The Crank Angle Sensor Is Getting Power
To get our crank angle sensor diagnostic started, we're going to make sure that it's getting 10 to 12 Volts DC.
The wire that delivers 12 Volts to the crank angle sensor, is the black with white stripe (BLK/WHT) wire of the engine wiring harness connector.
The BLK/WHT wire connects to the female terminal labeled with the number 1 in the photo above.
NOTE: The distributor's engine wiring harness connector has female terminals.
These are the test steps:
Set your multimeter to Volts DC mode.
Disconnect the 4 wire connector from the distributor.
Probe the terminal labeled with the number 1 with the red multimeter test lead.
Connect the black multimeter test lead directly on the battery negative (-) terminal.
Turn the key on but don't crank the engine.
Your multimeter should register 10 to 12 Volts DC.
Let's examine your test result:
CASE 1: Your multimeter registered 10 to 12 Volts. This is the correct test result.
Now that you know that the crank angle sensor is getting power, the next step is to make sure that it's getting Ground. Go to: TEST 2: Making Sure The Crank Angle Sensor Is Getting Ground.
CASE 2: Your multimeter DID NOT register 10 to 12 Volts. Without this voltage the crank angle sensor will not function.
Your next step find out why this voltage is missing and repair the problem.