Testing a No Start-No Spark or a Misfire Condition on your Nissan Mini-Van or Pick Up or SUV or the Mercury Villager (with the 3.3L V6 engine) is not difficult at all. No expensive tools or diagnostic equipment is needed, and this article will show you just how to do it step by step.

With the tests in this article, you'll be able to test and diagnose: A BAD power transistor, or a BAD ignition coil, or a BAD distributor cap, or BAD spark plug wires on your Nissan vehicle.

On the box titled ‘Applies To’ on the right column, you'll find a complete list of Nissan and Infiniti models that this test article applies to.

Puedes encontrar este tutorial en Español aquí: Prueba del Módulo y Bobina de Encendido 3.3L Nissan (1996-2004) (en: autotecnico-online.com).

Symptoms of a BAD Transistor, Ignition Coil, Spark Plug Wires, or Dist. Cap

If you're Nissan SUV or mini-van is suffering a Misfire... the check engine light (CEL) will be on to let you know that YES, there really is something wrong. Here are a couple of other symptoms your vehicle may experience with a Misfire Condition:

1. Diagnostic trouble codes (DTC) stored in the computer's (PCM) memory:

P0300, P0301, P0302, P0303, P0304, P0305, P03062. Misfire that does not light up the check engine light (CEL).3. No power.4. Idles rough.5. BAD gas mileage.6. Black smoke coming out of the tail-pipe.7. Rotten egg smell coming out of the tail-pipe.8. Smell of unburned gasoline coming out of the tail-pipe.9. Won't pass the state emissions test.

If the power transistor or the ignition coil is BAD, then the most common symptom is that your vehicle will CRANK but not START and there will be no spark at any of the spark plug wires.

Basic Nissan Ignition System TheoryTo be able to successfully diagnose a Misfire or No Start on your Nissan vehicle (whether it’ a pick up, SUV, or a mini-van) it'll help to know how spark is created

and fed to the engine cylinders. This is what happens in a nutshell when you turn the key and crank the engine:

1. The crankshaft position sensor and camshaft position sensors start to generate and feed their signals to the vehicle's PCM (Powertrain Control Module=Fuel Injection Computer).

2. The PCM uses these signals to know where each piston is at in relation to its combustion cycle and with this info, the PCM knows when to start activating the power transistor, the fuel injectors and a host of other things to get your Nissan vehicle started.

The power transistor is the ignition control module (ICM) in the Nissan vehicles.

The power transistor is located within the distributor assembly and is part of the cam sensor assembly.

3. So then, after receiving the crank (CKP) and cam (CMP) signals, the PCM sends the power transistor a Triggering Signal that tells the power transistor exactly when to activate the ignition coil.

4. The power transistor activates the ignition coil by opening and closing the Primary Current Circuit of the ignition coil... and as you may already be aware it's this opening and closing action that makes the ignition coil spark away.

5. The spark created by the ignition coil is fed to the distributor rotor directly by the distributor cap and then from there to each engine cylinder via a spark plug wire.

With the simple and easy tests presented in this test article you'll be able to find the exact cause of your Nissan vehicle's Misfire or No Start Condition (if it's ignition system related) and in the process save time and money.

Power Transistor Test and Ignition Coil Test 3.3L Nissan (1996-2004)

17 November 2010   Updated: 02 March 2015   Written by: Abraham Torres-Arredondo   Article Id: 389

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What Tools do INeed to Test the Ignition System?

Although the tests in this article are easy and simple, you do need some specific tools to perform them with. Here's the list:

1. An HEI spark tester This inexpensive spark tester is a MUST have tool to

be able to correctly diagnose the ignition system on your Nissan vehicle with the info and tests in this article (don't have an HEI spark tester? Need to buy one? You can buy it here: OTC 6589 Electronic Ignition Spark Tester ).

Don't use a regular spark plug instead of a spark tester.

2. Battery jump start cables.3. A digital multimeter that can read Hertz (Hz) frequency.

Without a multimeter that can read Hertz frequency, you won't be able to accomplish some of these tests. (don't have a digital multimeter that can read Hertz frequency? Click here to see my recommendations: Buying a Digital Multimeter for Automotive Diagnostic Testing).

4. A helper. You'll need someone to help you crank the engine

while you perform the tests in the engine compartment.

5. A repair manual. For whatever remove and replace info you'll need

that is not covered by this article.

Power Transistor/Cam Sensor AssemblyCircuit Descriptions

There are 6 wires coming out of the main distributor connector. This connector connects to the power transistor/cam sensor assembly that's located within the distributor.

Now, don't worry, you don't need to test all of them to diagnose this ignition system. Below are the circuit descriptions of all six wires (circuits):

Circuit labeled 1 o Triggering Signal for Power Transistor. This Signal

comes from the PCM. Circuit labeled 2

o Ground Circuit for the Power Transistor. Circuit labeled 3

o Camshaft Position Sensor Signal - 120° REF Signal. Circuit labeled 4

o Camshaft Position Sensor Signal -1° POS Signal. Circuit labeled 5

o Camshaft Position Sensor Power (12 Volts). Circuit labeled 6

o Camshaft Position Sensor Ground.

Ignition Coil Circuit Descriptions

The other connector has two wires coming out of it and both of these go directly to the ignition coil inside of the distributor. Here are their circuit descriptions:

1. Circuit labeled 1 Power (12 V) Circuit.

2. Circuit labeled 2

Switching Signal output to the PCM.

1

2

3

4

5

6

TEST 1: Testing for Spark at the Spark Plug Wires

The starting point of your Misfire or No-Start diagnosis is testing for spark at the spark plug wires. Now, you might already have a specific cylinder you want to test first (if you have a specific Misfire Diagnostic Trouble Code: P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308) or you just don't know

where to start. Well, my recommendation is to test all of the spark plug wires for spark regardless.

I want to stress the importance of using an HEI spark tester to perform all of the spark tests. Here are a couple of other important suggestions:

1. Do not use a regular spark plug in place of a spark tester.2. Do not pull the spark plug wire off of its spark plug while your

helper cranks the engine to verify spark. This will damage the ignition coil, if it isn't fried already.

OK, here we go:

1. Disconnect the spark plug wire from its spark plug.2. Attach the HEI spark tester to the spark plug wire.3. With a battery jump start cable, attach the HEI spark tester to a

good ground point or to the battery negative terminal.4. Have your assistant crank the engine while you eye-ball the spark

tester. If you're testing a Misfire Condition, the engine will start... so be careful.

5. Repeat the test for all of the remaining spark plug wires (if applicable).

6. You're going to see only one of two results: either spark jumping across the HEI spark tester's air gap or No spark.

CASE 1: If you got spark on all of the spark plug wires: This results let's you know that the power transistor, ignition coil, distributor rotor and cap are OK. Having all of the spark plug wires firing off spark eliminates all of these components as the cause of your Misfire Codes or No Spark- No Start Condition. For some suggestions as to what could be the cause of the misfire condition and/or Misfire Codes, go to TEST 8.

CASE 2: If you got NO spark from any (none) of the spark plug wires: The next step is check that the ignition coil is creating and feeding spark to the distributor cap. You'll accomplish in TEST 3. Go to TEST 3.

CASE 3: If you got spark on some but not all of the spark plug wires: The next step is check for spark directly on the distributor cap towers that feed spark to these wires that did not fire off spark. Go to TEST 2.

TEST 2: Testing for Spark at the Distributor Cap

It's not uncommon for a distributor cap to have one or more towers not transmitting spark from the distributor rotor to their respective spark plug wires. This problem, of course, this will cause a misfire condition.

This type of problem can be tested with a simple spark test. In this test step, you'll be testing for spark with the HEI spark tester directly on the distributor cap tower (or towers) whose spark plug wire did not fire off spark in TEST 1.

Important: this test is only for when one or several (but not all) of the spark plug wires did not spark!

1. OK, un-plug the spark plug wire (that didn't spark) from its tower on the distributor cap and place the spark tester directly on the tower.

2. With the same battery jump start cable you used in TEST 1, ground and hold the spark tester to the tower as shown in the photo.

3. Ask your helper to crank the engine while you observe the HEI spark tester.

4. Repeat this test with the others that did not fire off spark (if applicable).

You'll see one of two results: the HEI spark tester sparking or No spark. Let's analyze each of these results below:

CASE 1: If you got spark, Then the spark plug wire is BAD, replace all of them as a set. This will solve your misfire condition and Misfire Codes lighting up your CHECK ENGINE LIGHT (CEL). Now, if the rest of the distributor components (distributor cap and rotor) are as old as the spark plug wires you're replacing... I recommend replacing them too.

Here's the why of the No spark result: As the spark plug wire gets older, its normal resistance to spark increases to the point that the it can't and doesn't channel spark to the spark plug. This will either cause a misfire, or a lack of power, or a No Start Condition. Spark plug wires don't last forever, especially after-market ones (average life-span is 3 to 4 years).

CASE 2: If you got No spark, This is a clear indication that the distributor cap is BAD. Replace the distributor cap and distributor rotor as a set. This should solve your misfire problem. Now, if the rest of the distributor components (spark plug wires and spark plugs) are as old as the distributor cap and rotor you're replacing... I recommend replacing them too.

Here's why: As the distributor cap ages, the terminals that transmit the spark to the spark plug wires corrode. This corrosion increases the resistance to spark and over time (as more corrosion is created) this same corrosion stops the spark from passing thru' to the spark plug wires.

TEST 3: Testing the Ignition Coil for Spark

In this test step, you'll test for spark directly on the ignition coil's tower. Since the ignition coil is inside the distributor, you'll need to remove the distributor cap.

Also, since the test is performed with the engine cranking, the distributor rotor will rotate... so be careful and take all necessary safety precautions. In the photo you'll notice the distributor rotor off the distributor for safety reasons.

1. Place the HEI spark tester directly on the ignition coil's tower.2. Now, ground the HEI spark tester with the same battery jump start

cable you have been using for the previous tests.3. When all is ready, have your helper crank the engine as you hold

the HEI spark tester in place.4. As before, observe the HEI spark tester to see if spark jumps

across its air gap.

You'll get one of the 2 results: (1) spark or (2) No spark. Let's analyze each result in more detail below:

CASE 1: If the spark tester sparked, this result confirms that the distributor cap is BAD. Replace the distributor cap and rotor as a set and your No Start Condition should be solved.

CASE 2: If the spark tester DID NOT spark. Then further testing is required to see if the problem is due to a BAD Nissan power transistor or something else. You're gonna' find out with the rest of the tests, Go To TEST 4.

TEST 4: Ignition Coil's Power (12 V) Circuit

If you've reached this point, it's because you've gotten a No spark result from all of the spark plug wires, the distributor cap and the ignition coil on your Nissan vehicle. In this test step you're gonna' verify that the ignition coil is getting a good supply of juice (10 - 12 Volts DC).

1. Select Volts DC mode on your multimeter.

2. With the RED multimeter test lead probe the wire identified with the number 2 in the photo. This should be the Black with White stripe wire of the two wire distributor Connector (the distributor has one 6 wire connector and a 2 wire connector).

3. Connect the BLACK lead of the multimeter to the battery (-) negative terminal.

4. Ask your assistant to turn the Key On with the engine Off.5. You should see 12 Volts on the multimeter. Do you have 12 volts?

CASE 1: If your multimeter displayed 12 Volts, this is good since it let's you know that the ignition coil is getting power, the next step is to check to verify that the ignition coil is being fed with the Switching Signal that comes from the power transistor... go to TEST 5.

CASE 2: If your multimeter DID NOT display 12 Volts, you must find out why you're missing this voltage. Without this voltage the ignition control module (ICM) nor the ignition coil will work. Resolving this power issue should solve your No Start - No Spark Condition.

TEST 5: Testing the Ignition Coil's Switching Signal

OK, as you may already know, the power transistor is the one responsible in activating the ignition coil to start sparking away on your Nissan SUV (or Pick Up or Mini-Van). It does this by a Switching Signal and this signal can be easily

tested with an LED Light. In this test step you're gonna' verify if indeed this signal is being supplied to the ignition coil. Alright, let's get started:

1. This test must be done with both of your Nissan distributor's connectors connected.

2. Connect the BLACK lead of the LED Light to the wire (circuit) identified with the number 1 in the photo. This should be the Blue wire of the two wire distributor connector (the distributor has one 6 wire connector and a 2 wire connector).

3. Connect RED lead of LED to the battery (+) positive terminal. It is IMPORTANT that it be connected at the battery positive terminal.

4. Have an assistant crank the engine.

If everything is working like it should, the LED Light will blink on and off the whole time the engine is being cranked. Don't worry about what the LED Light does before or after your helper starts cranking the engine. The only results you're interested in interpreting are the results obtained with the engine cranking.

CASE 1: If the LED flashed On and Off, then the ignition coil is BAD, replace it. This also means that the power transistor is GOOD. Replacing the ignition coil will solve your No Spark/No Start Condition. The only thing that sucks is that at the time of this writing, you cannot buy the ignition coil separately... you have to buy the whole distributor.

CASE 2: If the LED DID NOT flash On and Off, re-check all of your connections and retry the test again. If still no light pulses on the test LED, go to TEST 6.

TEST 6: The Power Transistor's Ground Circuit

For the power transistor to activate the ignition coil, it has to have a good path to ground and in this test will help you to verify that it does.

For this test you can use a multimeter or a test light, although the test steps assume that you're using a multimeter:

1. Select Volts DC mode on your multimeter.2. With the multimeter's BLACK test lead probe the wire identified with

the number 2 in the photo of the 6 wire distributor Connector.3. Connect the RED lead of the multimeter to the battery (+) positive

terminal.4. You should see 12 Volts on the multimeter without having to turn

the Key to ON. Do you have 12 volts?

CASE 1: If your multimeter displayed 12 Volts, this is good since it let's you know that the power transistor has a good path to ground, the next step is to check to verify it's receiving a Triggering signal from the Fuel Injection Computer... go to TEST 7.

CASE 2: If your multimeter DID NOT display 12 Volts, then there's a problem with the ground circuit. Without ground the power transistor cannot activate the ignition coil to start sparking. Resolving this ground issue should solve your No Start - No Spark Condition.

TEST 7: Testing the Triggering Signal from PCM

For the power transistor to activate the ignition coil, it has to receive the instructions do so from the Fuel Injection Computer. This is done by a signal called the Triggering Signal (although this is not Nissan's technical name for it).

In this test, you're gonna' check to see if the power transistor is being supplied with it when the engine is being cranked. For this test you'll need to use a multimeter that can read Hertz frequency... an LED Light will not work here since the signal's frequency is so fast that you can not see it with an LED Light. OK, let's get started:

1. It's important that the battery be in a fully charged condition for this test.

2. Select Hertz (Hz) frequency mode on your multimeter (don't have a digital multimeter that can read Hertz frequency? Click here to see my recommendations: Buying a Digital Multimeter for Automotive Diagnostic Testing).

3. Connect the RED lead of the multimeter to the wire labeled with the number 1 of the distributor's 6 wire connector with an appropriate tool.

4. The multimeter's BLACK lead goes to the battery's negative terminal.

5. Once everything is set up, have your helper crank the engine while you observe the multimeter.

6. If the Nissan's Fuel Injection Computer is feeding the Triggering Signal, you multimeter will register around 6 to 8 Hertz (Hz) on its display screen.

CASE 1: If the multimeter registered 6 to 8 Hertz (Hz), this confirms that the power transistor is fried and needs to be replaced. Replacing it will solve your No Spark - No Start problem. Now, at the time of this writing the only way to buy a power transistor is to buy the whole distributor.

CASE 2: If the multimeter DID NOT register 6 to 8 Hertz (Hz), recheck all of your connections. If still the multimeter does not register the indicated Hertz values, this indicates one of three things (as the possible causes of this missing signal): 1) A BAD crankshaft position sensor or 2) an open in this circuit between the power transistor and the PCM or 3) a BAD PCM, although this is rare.

TEST 8: Other Causes of a Misfire

So you've done all of the spark tests, and still your Nissan pick up (or mini-van, or SUV) is still running rough (rough idle) and/or the Misfiring. Well, here are a couple of suggestions that might help...

1. The valve cover gaskets are leaking oil onto the spark plug wells and soaking the spark plugs and spark plug wire boots in oil.

Over time, this oil will cause a misfire as the oil cooks and turns into carbon tracks.

The photos in the image viewer show you what a carbon track looks like on the inside of the spark plug wire boot and on the ceramic insulator of the spark plug.

2. Engine compression test

One of the most overlooked diagnostic tests to find the root cause of misfire is the compression test.

You'll need an engine compression tester of course. The engine compression readings between cylinders

should not vary more 15%.3. Carbon tracks on the spark plug(s) and in the inside of the spark

plug wires. The photos in the image viewer point (the orange

arrows) to what carbon tracks look like. Replace the components as affected with carbon

tracks.4. Broken spark plugs.

This usually happens at tune-up time, if you have dropped one on the floor.

You power washed the engine... this is something that should never be done on any Nissan vehicle.

If this info really saved the day, buy me a beer!