Where to test ignition coils with ohm meter
 

This come with a long pre-story but I wont bore you with it, I just need to know how exactly I go about testing the coils with an OHM meter to see which is the bad one.
Here is a pick to help out with possible descriptions.
http://people.umass.edu/aapaglia/i3b.JPG
Also if you know of another way to test which is the bad coil that would help, I was told one way is to start the car and remove one and see if the car sounds worse, if its no dif then that’s the bad one… the problem is I am not going to be able to do the work I have to tell a friend how to do it (out of town) but they are not very mechanically savvy, on and off tests he can do for me but he says he wont do the test while the car is on.

-aPeG

For the second method, all you have to do is unplug the coil pack. It's right there, just reach over and unplug it.

I'm about to do this too to my 99 I30, as I'm starting my winterbreak from college. Anymore help anyone? For the second method, how much "worse" can it sound. Will it be noticeably different, or would I have to try multiple times to notice the difference. Is this method more advisable than the OHM meter thing? Much thanks.

:) I was wondering what car is in the picture and from the VIN I see that it is a 2000 I30 and therefore has black intake :) Mine is silver...

In order to test the coil, take it out. Measure the resistance in the following manner:

POS to 1 and NEG to 2 -- should show infinite resistance
POS to 2 and NEG to 1 -- should show continuity but not zero ohms
POS to spark plug and NEG to 1 -- should show infinite resistance
POS to 1 and NEG to spark plug -- should show infinite resistance

Connector number 3 is a trigger and is not measurable.

Connector:

___|--|___
| 3 | 2| 1 |
-----------

If any coil shows otherwise than it sould be replaced.

If I remeber correctly, the resistance between pin 1 and 2 was about 16- 21 ohms on my 96' but dont quote me on that. I did it long time ago.

Hope it helps.

regards, Bart.

When Youll remove the connector the engine will shake a lot. Trust me, you will notice the difference.

regards, Bart.

ps: why do you guys want to test the coils?

i have a bad coil i think. when at drive and stopped, it shakes spontaneously. I think it happens on neutral as well, i don't remember. sometimes it happens sometimes it doesn't, so i'm weary whether taking each ignition coil off then starting the car would work. I'm thinking the ohm reader would work better. i've been told on this board, as well as a dealership that it's most likely a ignition coil gone bad, since 99 maximas/i30s tend to have that problem.

anyone know a site where i can buy 1 cheap ignition coil if i determine which one is bad? the front and rear coils are different, so i'm not sure which one to get yet, but will know after i have a friend test it for me.

I went to my local infiniti dealership and bought two for $75ea if I remember correctly. Funny tho because my coils were ok. When I was measuring them, two had slightly higher resistance..... I thought that would make them bad... but I was wrong :) I still dont know what should be the exact resistance, probably anything over 500ohms is bad... I just dont know..

regards, Bart.

Did you try to clean the intake throttle? My I30 had problems starting and rogh idle. After I cleaned the throttle, everything went away! Try it, see my post at:

http://forums.maxima.org/showthread....40#post3487440

regards, Bart.

yea that's been done with the right cleaner already.

Some simple direction?
 

http://people.umass.edu/aapaglia/i3b.JPG

How to get the green clips to unplug? In the picture you see the green clips which I assume are the connection to the ignition coils, I need to get those off to do the tests on the coils but am having very little luck? I tried to a pair of pliers but I don’t want to go too hard because they are just plastic clips and I may break them.

Well after all this time I finally took care of the Ignition coil problem and thought i would post my finding for people who may be is the same situation:

I decided to try the ohm meter test first just because it is easy and I want to see if it will actually work... and IT DID ;-)

Now i forget which direction I was holding the coil @ the time of testing but you should get the idea, ohh and thanx to SKORPiO for the method but just to play it safe i did all combinations:
--------------------------------------------------------------------------
Results front 3 coils (looking @ the front of the car) left to right, i__ = infinity or 0
_________Coils
Pins._| #1 | #2 | #3 |
-2,+3 |06.5|07.0|06.5|
+2,-3 | i__ | i__ | i__ |
-1,+2 |35.0|35.0|35.0|
-1,+3 |15.0|14.0|12.5|
+1,-2 |12.0|16.0|13.0|

Results back 3 coils (looking @ the front of the car) left to right, i__ = infinity or 0
_________Coils
Pins._| #4 | #5 | #6 |
-2,+3 |06.5|06.0|06.0|
+2,-3 | i__ | i__ | i__ |
-1,+2 | i__ |32.0|30.0|
-1,+3 | i__ |12.0|12.0|
+1,-2 | i__ |250.|13.0|
--------------------------------------------------------------------------
Without a doubt coil #4 is the dead one, reporting "i" results when the rest were all uniform, I have order the new coil and it will be here tomorrow. Coil #5 is the one that worries me, as you can see it reports values just like all the others EXCEPT for (+1,-2) I tested it 5x and came up with 250-300, which is WAY off. So currently the plan is to replace #4 then resent to ECU and see if the light comes back because of #5.

Hope this helps you guys out

-aPeG

To be sure to understand,

you apply + battery 12 V on the pin 2
and you apply the negative - battery 12 V on the pin 1

after you read with ohm meter the resistance between the pin 2 and pin 1 ?


we must read between on ohm meter: between 15 and 36 ohm ?


thanks

Hey Dan, its been a chunk of years since i made this post... but heres what i can remember:

each coil has 3 pins, i want to test all permutation for those 3 pins (1-2)(1-3)(2-3). but there is also - + from the ohm meter, so that gives (-2,+3)(+2,-3)(-1,+2)(-1,+3)(+1,-2)

from there just graph all your results and the odd ball out will be your bad coil. good luck.

-aPeg

Hi aPeg,

I have Maxima 95

To test:

Turn on your ohmmeter and place the positive wire on the 1st prong in the electrical plug of the coil pack. The negative wire should be touching the middle prong. Verification of the ohmmeter at this time should say infinite...

if it's anything else, the pack should be changed. Next test: reverse the wires... positive on the middle prong and negative on the 1st prong.... on a new coil pack, value of approximately 1.1-1.2 mega ohms for all coils

i do not have your values with ohm meter like: +1,-2 |12.0|16.0|13.0| ohms

thanks

On my Maxima 95

With Ohm meter

Results front 3 coils (looking @ the front of the car) left to right, i__ = infinity

K: Kilo
M: Mega
_________Coils
Pins._| #1 | #2 | #3 |
-2,+3 |1.45K ohm | 1.61K ohm | 1.81K ohm |
+2,-3 |1.45K ohm | 1.61K ohm | 1.81K ohm |
-1,+2 |1.16M ohm | 1.11M ohm | 1.07M ohm |
-1,+3 |1.16M ohm | 1.11M ohm | 1.07M ohm |
+1,-2 | i | i | i |

On my Maxima 95

With Ohm meter

Results back 3 coils (looking @ the front of the car) left to right, i__ = infinity

K: Kilo
M: Mega
_________Coils
Pins._| #4 | #5 | #6 |
-2,+3 |1.52K ohm | 1.49K ohm | 1.71K ohm |
+2,-3 |1.52K ohm | 1.49K ohm | 1.71K ohm |
-1,+2 |1.16M ohm | 1.18M ohm | 1.10M ohm |
-1,+3 |1.16M ohm | 1.18M ohm | 1.10M ohm |
+1,-2 | i | i | i |

Problem with my Nissan Maxima 95 when we have humidity.

When he starts the morning, if we have humidity, he starts, but RPM not to keep 700 tr/min and will go down (stall)
i need to give a little bit gaz to keep RPM above 700 RPM for 1 sec and it's OK

No problem when it's cold (-15 celsius) and no problem when it's dry or beautiful, the Nissan Maxima starts very good
i have only this problem when we have humidity

No engine code about that

May be a coil cracked ? or Mass Air Flow ?

I have other Coil ignition to make a test

thanks

i suspect my ignition coils are bad and i followed the instructions on this thread to test them. the problem is my ohm meter only shows any reaction at connections -1, +2 or +1, -2. all others it doesn't even seem to register.
it shows results ranging from 1.3k to 1.5k. somehow i feel like im doing this wrong..

I get the same results as you. I am testing with coil packs out of the engine. It shouldn't matter whether the coil is in the car or not, since the coil only contacts the plug electrode and does not have a ground connection when unplugged, but perhaps it still conducts in the MOhm range through the plastic case?

eBay
 

eBay I bought one for about 17.50 with shipping and tax

Welcome to Maxima.org.

We appreciate your willingness to offer advice and solutions but you need to look at the date on the post you are replying to.

You responded to a post made in December of 2004, almost 11 years ago. I doubt that lawrencel715 is still waiting for someone to advise him.

But don't stop. Just watch the details like dates.

Am I doing something wrong here:

coils__| #6 | #5 | #4
-2, +3 | 1.87 | 1.88 | 1.88
+2, -3 | 1.87 | 1.88 | 1.88
-1, +2 |__i___|__i___|__i__
-1, +3 |__i___|__i___|__i__
-1, -2 |__i___|__i___|__i__

I tested these on 2 different Digital V.meters.

P1320 2001 Nissan Maxima - I tested my coils but my R>>>R Bart!
 

I just got the third on in question out, aka all 3 rear ones and tested resistances as suggested. All infinite resistances check out, but here's what I got:
Driver's side 1-2 = 2.660 M ohms

Middle 1-2 = 2.498 M ohms

Passenger side 1-2 = 2.506 M ohms

It ran fine this evening when started, then, as usual, after 5 minutes sounded like it was missing. I pulled 2 of the 3 plug connectors individually and it was quite noticable.

Just the same, when it wants to, it sounds like it runs on 3 cylinders, idling too low, sometimes stalling when at a red light.

Also, the CEL had been flashing at me in the past 3 weeks and I know that means "OUCH!!! Pull over NOW and have me towed to the stealership!!!"

I have yet to as I know they'll stick it in my eye, and I want to tackle this myself. Only paid a mechanic a red cent 2× in my 28 years of spinning wrenches.

Thanks!

There is a transistor inside the coil pack and that is what you are checking the resistance of. If you are having a transistor failing when it gets hot, which is not uncommon for a transistor to do, then you have to check it when it is hot.

When something is intermittent, you have to catch it while it is failing.

That testing when hot makes sense, but doesn't my R of 2,600,000 ohms sound a BIT hi?
 

I will try that and already did with the front coils, it was running on 5 cylinders after work when I did. Pulling the 3 pronged plug on top of each front coil did not make a discernable difference so that says all 3 front coils are AOK. Great, only the PITA to get to 3 in the back coils be at fault. Lucky me. ;)

My Haynes manual made another mistake, saying "remove intake manifold to get to and remove the coils."

That's the 2nd mistake I found those Brits make. The 1st was "To replace fog light bulbs, take the car to the dealership."

Hmm, how bout you writers at Haynes catch a clue and remove the inner front fender well and reach betweeen the bumper solid support and the plastic lower lip of the bumper cover and pop the connector loose. Sure, like most Nissan electrical connectors, they're a PITA to get released but they CAN be replaced by your average shade tree mechanic and it DOESN'T require you to pay the stealership an exorbitant amount to replace 2 bulbs.

All that being said, I appreciate the input and just wanted confirmation that my reading of 2.49-2.60 million ohms resistance between pins, depending on which coil was tested, was too high before I go to the auto parts store and pickup 3 non-returnable coils to the tune of $174, especially if they're not the problem.

I will try and reassemble the air box and whatnot tonight to get it running again and drive around for 20+ minutes to get it all heated up, Mag Lite & 10mm socket wrench in hand, so that I can pull coils and retest their resistance when hot.


Still, anyone else, please let me know the reading you got for coil resistance. Also, I'm afraid my dad's brand new Fluke might be a POS because it's not acting properly.

Thank you all!

The problem with Haynes manuals is that they cover 5 or more years of a car and there are changes to the cars in that long of a time. The Haynes manual shows/describes one way and if there are changes in the years the manual covers, they ignore them.

On the 3.5 liter engine, you have to remove the upper intake manifold to get to the ignition coils and spark plugs for the 1, 3, 5 cylinders. On the 3.0 liter engine you do not have to.

You can download an Infiniti manual from here:

http://boredmder.com/FSMs/Infiniti/

I didn't see any mention of what year your car is. It makes a difference as 99 & earlier coils have the pin numbers reverse of the 2000 & up. But it is a labeling difference. Pin 3 of a 1999 is the same internal connection as pin 1 of the 2000.

Measuring between pins 1 and 2 on a 1999 is measuring the same thing as measuring between pins 3 and 2 on a 2000.

Looking at the coil
When i measured the coils on my 2000 Maxima, I did not get a 2.5M ohm reading

This was a VERY useful thread! I measured all of my coils and they seem to have constant values among all 6 coils, I changed the coil condenser, and all of the harness plugs have 12+ volts going to them but I'm still getting the P1320 trouble code.

-B

Are your coils all original? Aftermarket ones may technically work, but the PCM can be touchy interacting with aftermarket coils.

Get used Ignition coils from an auto wrecking yard. They are inexpensive. Test a good one on the car, then test used ones at the yard before buying them.

OHM meter showed good values but still an ignition coil was bad
 

I know I'm responding to an old thread, but I found the issue yesterday and fixed it today. My 2000 Nissan Maxima was showing P1320 code along with Random misfire code and I tested all my 6 ignition coils with OHM meter and all of them showed correct ranges of resistance values. So I installed all the ignition coils back on and started the engine and started removing the power (12 V harness connector) from each ignition coil one by one. Everytime I removed the power I could hear the engine RPM slowing down and everytime I plug it back on, I could hear engine RPM going up except for one ignition coil which was the bad one.

So my point is, don't just rely on OHM meters testing alone. Remove power from each ignition coil and put it back on one by one and the one that doesn't make any difference in the engine RPM is the faulty one.

An ole school timing light works too!