ADROX

hi guys I have a 96 automatic max. I'm having trouble getting this to clear. had the car put on a computer at a shop and could not get a specific problem out of it. my mechanic did say that the problem would be in the front center cylinder, probably the coil. he got that conclusion from unplugging every coil one at a time when the car had a high idle. stated when he unplugged that particular coil pack the motor did not make a change as far as idle or having a miss. so I spent $130 on a new nissan coil pack and still had the code. I would assume it would have gone away if it was fixed. it also chugs pretty bad but only when in reverse. it's had this code for awhile. I have put a brand new egr tube on it and all newgaskets on evrything I had to take apart to get there, ran seafoam, switched all of the coils out with nissan coils out of a junkyard, replaced knock sensor (cleared that code), replaced all the plugs 6 months ago usualy use chevron plus or supreme. at a total loss as of now and car only gets 21/22 mpg.
these are what are listed as possible problems, question is how do I test stuff like the camshaft positioning sensor etc...

0201
Diagnostic Trouble Code 0201 indicates a problem with the ignition coil and power transistor. The ignition signal from the Engine Control Module is sent to and amplified by the power transistor. The power transistor turns on and off the ignition coil primary circuit. This on-off operation induces the proper high voltage in the coil secondary circuit.

The malfunction is detected when the ignition signal in the primary circuit is not entered during engine cranking or running.

The items to check include
- Harness or connectors (the ignition primary circuit is open or shorted.)
- Power transistor unit built into ignition coil
- Condenser
- Crankshaft Position Sensor (REF)
- Crankshaft Position Sensor (REF) circuit

maxgtr2000

iTrader: (29)

If the coilpack was replaced and still misses, then the problem maybe with the harness or the channel from the ecu feeding that coil. This code comes when the ecu checks the ground resistance of the coil. Also the condenser igniter which is 50mf capacitor (in a small black box shaped case) can go bad and possibly cause that code.

ADROX

is the condensor in a box behind the drivers side headlight? the box is broken like it might have gotten that way from a wreck. the relays and such are all kinda loose because of this.

DennisMik

iTrader: (2)

No. The condenser is taped onto the wire harness that runs along the valve cover over the #6 cylinder. The box you are talking about is strictly relays.

ADROX

ok yeah I did some research and found its in the harness and pretty cheap even at nissan. guess Ill pick one up tomorrow as long as theyre under 10 bucks. just one for the whole motor or correct?

ADROX

ok so found the ignition coil condensor. it looks like either it has melted a little or somebody rtv'd it in there. i cant get it to unplug.
cant figure out how to upload a pic of it from computer

finally got it apart and looks to be burnt. keeping fingers crossed its the problem!
on $10 from nissan dealer btw

ADROX

ok not happy. so changed the conensor out and still have the code. cleared it with a scanner and it came back on within 5 miles, then reset the ecu and drove it for 40 miles. no light but cause was showing on the scanner, as soon as I put the car in reverse and it did its shuttering thing the light came on. totally frustrated at this point, really can't afford the money for a shop much less throwing money in on parts that don't fix it. anyone have any other ideas? gonna borrow a multimeter tomorrow and test the crank sensor. btw I did take that out and clean the metal end with some carb cleaner just to see if that would help. wierd how last two times the light came on was when it went into reverse but that is also when it has that bad 'miss' and the code was sitting there already anyway.
guess next step is to measure resistance between coils and ecu with a multimeter. maybe find one with a broken wire in the harness

ADROX

ok checked for power from coil harnesses to ecu, seemed good, they all read the same on the multimeter just not sure if I did it right. not sure how to measure rsistance with a multimeter. checked the camshaft sensor it was within specs, checked the crankshaft sensor (ref) it was within specs and was extremely oil soaked. cleaned the connection and the little hole the magnet sits in. still the code is there.

maxgtr2000

iTrader: (29)

Like I said it also comes from the resistance of the coils when the ecu does the coil check. I had this code for years running an emanage blue with ignition harness (coilpack ecu wire intercepts). The coil packs can fire good and read within spec. You could try replacing the coilpacks one by one. The fix for this when running engine management was to add a certain ohm resistor to the wires but this is only when running intercepts. So basically it boils down to the coilpacks.

ADROX

just find it hard to believe its the coils because the car had hanshins in it when I got it with the code and the junkyard ones are nissan. I did find that the the boost sensor probably has a vacuum leak on it. it's something that needs to be fixed anyway so ordered another one for 12 bucks on ebay. I guess at one point the port got broken off so they siliconed a vacuum tee on the bottom of it. I noticed I could spin the tee a little with my hand so it doesn't look like a very good seal job. maybe that might help me??? if the idle n such have a little to do with vacuum then I guess it's possible. like I said it needed to be fixed right anyway.