How To Test The Starter Motor (1996-1997 3.3L Pathfinder)

TEST 6: Testing The Inhibitor Switch Signal

In this section, we're gonna' make sure that the inhibitor relay is getting an Inhibitor Switch Signal.

As mentioned earlier the inhibitor relay only receives this signal when the automatic transmission is in Park or Neutral.

This signal is a 12 Volt signal that arrives on the female terminal labeled with the number 1 in the photo above.

We'll use a multimeter to verify the presence of this 12 Volt signal when the key is turned to start the engine.

NOTE: The automatic transmission must be in Park or Neutral for this test to work.

These are the test steps:

1. 1

   Disconnect the inhibitor relay from its connector.

2. 2

   Place your multimeter in Volts DC mode.

3. 3

   Probe the female terminal labeled with the number 1 with the red multimeter test lead.

4. 4

   Connect the black multimeter test lead to the battery negative (-) terminal.

5. 5

   Have your helper turn the key to crank the engine.

6. 6

   The multimeter should read 10 to 12 Volts DC with the transmission in Park.

Let's examine your test results:

CASE 1: 10 to 12 Volts are present. This is the correct test result and tells you that the inhibitor switch is OK.

The next step is to check that the inhibitor relay is getting Ground. For this test go to: TEST 7: Making Sure The Inhibitor Relay Has Ground.

CASE 2: 10 to 12 Volts ARE NOT present. This test result usually tells you that the inhibitor switch or the ignition switch is bad.

Your next step is to test the inhibitor switch.

TEST 7: Making Sure The Inhibitor Relay Has Ground

If you've reached this point, you have:

• Confirmed that the starter motor cranks the engine only when you bypass the inhibitor relay (TEST 1).
• Confirmed that the inhibitor relay is getting a Start Signal (TEST 5).
• Confirmed that the inhibitor relay is getting an Inhibitor Switch Signal (TEST 6).

In this test section, we're gonna' make sure that Ground is present in the female terminal labeled with the number 2 in the photo above.

To test for the presence of this Ground we'll do a simple multimeter voltage test.

These are the test steps:

1. 1

   Disconnect the inhibitor relay from its connector.

2. 2

   Place your multimeter in Volts DC mode.

3. 3

   Probe the female terminal labeled with the number 2 with the black multimeter test lead.

4. 4

   Connect the red multimeter test lead to the battery positive (+) terminal.

5. 5

   The multimeter should read 10 to 12 Volts DC.
   
   NOTE: You should have 10 to 12 Volts with the key on or the key off.

Let's examine your test results:

CASE 1: The multimeter registered 10 to 12 Volts. This is the correct and expected test result and confirms that the inhibitor relay is getting Ground.

You can conclude that the inhibitor relay is bad and needs to be replaced only if you have:

• Confirmed that the starter motor cranks the engine only when you bypass the inhibitor relay (TEST 1).
• Confirmed that the inhibitor relay is getting a Start Signal (TEST 5).
• Confirmed that the inhibitor relay is getting an Inhibitor Switch Signal (TEST 6).
• Confirmed that the inhibitor relay is getting Ground (this test section).

NOTE: Take a look a the section: Bypassing The Inhibitor Relay Is Not A Repair Solution.

CASE 2: The multimeter DID NOT register 10 to 12 Volts. This test result tells you that Ground is not present at female terminal #2. Without Ground the inhibitor relay will not activate the starter motor when your turn the key to start the engine.

Your next step is to repair the Ground wire that connects to female terminal #2.

Bypassing The Inhibitor Relay Is Not A Repair Solution

If bypassing the inhibitor relay got your 3.3L Nissan Pathfinder to finally crank and start, don't be tempted to consider this the repair solution for your 3.3L Nissan Pathfinder.

Bypassing the inhibitor relay is only a test procedure and not a repair. Why? Because bypassing the inhibitor relay eliminates a very important safety precaution built into the starter motor system circuit.

To be a bit more specific: It eliminates the neutral/safety switch from the system. This means that the engine can start in any gear! By any gear I mean that it can start in Drive or Reverse.

Jumper Wire Example

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.
• How To Test The Camshaft Position Sensor (3.3L V6 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).