The camshaft position sensor, located inside the distributor, is the heart of the ignition system on the 1993-1998 3.0L Nissan Quest or Mercury Villager.
When it fails the 3.0L V6 engine in your mini-van will not start due to a lack of spark at all six cylinders.
The cool thing is that the camshaft position sensor can be easily tested to find out if it's bad or not.
In this tutorial I'm gonna' explain the four essential tests you need to do to find out if the camshaft position sensor is defective (or no).
NOTE: The camshaft position sensor in the 1993-1998 3.0L Nissan Quest and Mercury Villager is also known as the crankshaft position sensor (although it's located in the distributor).
Contents of this tutorial at a glance:
This tutorial applies to the following vehicles:
- 3.0L V6 Nissan Quest: 1993, 1994, 1995, 1996, 1997, 1998.
- 3.0L V6 Mercury Villager: 1993, 1994, 1995, 1996, 1997, 1998.
WIRING DIAGRAM: You can find the ignition system wiring diagram for the 3.0L V6 Nissan Quest and Mercury Villager here:
You can find the ignition coil and power transistor tests explained in detail here: How To Test The Ignition Coil And Power Transistor (1993-1998 3.0L Nissan Quest).
Important Tips And Suggestions
TIP 1: In TEST 3 and TEST 4 you're gonna' test for the presence of the camshaft position signals. It's important that you turn the engine by hand using a 1/2" ratchet wrench on the crankshaft pulley to get a correct test result. Don't use the starter motor!
TIP 2: Disable the fuel system before you perform TEST 3 and TEST 4. The fuel pump ban be disabled by removing the fuel pump fuse.
The fuel pump fuse location:
- 1993-1995 3.0L Quest and Mercury Villager: fuse 8 of the dash fuse box.
- 1996-1998 3.0L Quest and Mercury Villager: fuse 45 of the engine compartment fuse box.
TIP 3: Before you test the camshaft position sensor, you must first test the ignition coil. If the ignition coil sparks then you can conclude that the camshaft position sensor is good and therefore you don't need to test it.
You can find the ignition coil and power transistor tests explained in detail here: How To Test The Ignition Coil And Power Transistor (1993-1998 3.0L Nissan Quest).
TIP 4: If your test results confirm that the camshaft position sensor is bad then you're gonna' have to buy the entire distributor since it's not sold seperately (and if it is, it usually cost an arm and a leg).
How Does The Cam Sensor Work?
Here's a very brief description of how the camshaft position sensor works:
- The camshaft position sensor is located inside the distributor and its job is to tell the fuel injection computer the positions of the pistons (especially the position of piston #1).
- The cam sensor assembly is really a crankshaft position sensor, since the fuel injection computer uses it to control the creation of spark (thru') the power transistor and ignition coil.
- When you turn the key and crank the engine (to start it), the camshaft position sensor gets 12 Volts and Ground.
- As the engine turns, the camshaft position 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 120° REF signal.
- When the computer gets these two signals, it sends 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.
- With this ON/OFF signal the ignition coil starts to spark.
When the camshaft position sensor fails on your 3.0L Nissan Quest (or Mercury Villager); the engine is not going to start due to a lack of spark.
You're also going to see a trouble code 11: Crankshaft Position (CKP) Sensor registered in the fuel injection computer. This code will light up the check engine light on your Nissan's instrument cluster.
TEST 1: Making Sure The Cam Sensor Is Getting Power
The camshaft position sensor, in your 3.0L Nissan Quest (Mercury Villager) needs 12 Volts and Ground to generate its signals.
For our first test we're gonna' make sure that the camshaft position sensor is getting 10 to 12 Volts DC.
On the 1993, 1994, 1995 3.0L Nissan Quest and Mercury Villager, 10 to 12 Volts are fed to the camshaft position sensor by the red with black stripe (RED/BLK) wire of the distributor's 4-wire connector.
On the 1996, 1997, 1998 3.0L Nissan Quest and Mercury Villager, the camshaft position sensor gets 10 to 12 Volts on the black with white stripe (BLK/WHT) wire of the distributor's 4-wire connector.
NOTE: You'll be testing for 10 to 12 Volts on the 4-wire connector that belongs to the engine wiring harness. This connector has female terminals (as shown in the photo above).
These are the test steps:
- 1
Set your multimeter to Volts DC mode.
- 2
Disconnect the 4 wire connector from the distributor.
- 3
Probe the female terminal labeled with the number 2 with the red multimeter test lead.
NOTE: Be careful not to damage the female terminal of the connector with the red multimeter test lead. - 4
Connect the black multimeter test lead directly on the battery negative (-) terminal.
- 5
Turn the key on but don't crank the engine.
- 6
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 camshaft position sensor is getting power, your next test is to check for the presence of Ground in the female terminal labeled with the number 3. For this test go to: TEST 2: Making Sure The Cam Sensor Is Getting Ground.
CASE 2: Your multimeter DID NOT register 10 to 12 Volts. Without this voltage the camshaft position sensor will not function and if it does not function the fuel injection computer will not activate the ignition coil.
Although it's beyond the scope of this tutorial your next step is to find out why this voltage is missing and repair the problem. The following wiring diagram will help you: Ignition System Wiring Diagram (1993-1998 3.0L Nissan Quest).
