INFINITY T OBDII - PO306 CYLINDER 6 MISFIRE PROBLEM/ETC.
1999 Infiniti Q45
January, 17, 2011 AT 3:04 PM
I have an Infiniti Q 45t and recently the check engine light came on - same month I needed state inspection too. Car passed the safety portion but OBDII portion failed. The OBDII diagnostic troble code was P0306 "Cylinder 6 Misfire Detected". The spark plug was fine; was told it needed an Ignition Coil. It was replaced. I was then told I needed to drive the car 75-100 miles and the onboard computer would reset itself. However, when I went to pick up the car, now the TCS/OFF & SLIP indicator lights were on! When I went back inside & spoke to the so-called head mechanic, I was told to drive it and the TCS/SLIPlights would go off within miles. Well it's been 125 miles later and NONE of the lights have gone off. So, my questions are
A) What would cause the TCS/OFF/SLIP lights to come on while changing an ignition coil?
B) Is it true that driving 75-100 miles would reset the onboard computer after replacing the Ignition Coil? (When I called back - after driving +100 miles - I was told they could remove all the warning lights for $125.00)
C) What other possibilities are there for the PO306 to still be on?
D) Besides filing a complaint with DMV, BBB, BCA, AAA what do U suggest I do to resolve ASAP as my car was inspected Dec (failed OBDII) and it's now mid Jan.
Thanks for your anticipated assistance
The first thing that comes to mind is that the repairing facility is staffed by some folks that need to have some customer service skills beaten into them! The traction control system has a warning lamp on, this is not in dispute, what I would need to determine is if there is a reason or reasons the TCS is setting a fault. Who knows? The system if activated by possibly setting the car on a dynomometer and spinning just the drive wheels to run the emissions test (in California, we dyno test most of the cars cars in most areas of the state) should either reset itself or should have been reset by the aforementioned customer service challenged repair facility, once again, shame on them. If the P0306 code was still present and causing trouble, the check engine light would still be illuminated. I would check to see if your state has a watchdog type system set up or actually call the state licencing board and see what they say. I am a firm believer in holding the "crooks" in auto repair accountable, the bad apples give the industry a bad name. And lastly, the standards that govern OBDII are such that the drive cycle, if completed to the car makers guidelines, should complete the readiness monitors and allow you to successfully complete the emissions test. I will be standing by if you need more assistance mate, good luck and do not be afraid to hold their feet to the fire!
January, 17, 2011 AT 5:14 PM
Thanks for your timely response. However, I would ask you attempt to answer my original questions with more detail. Specifically,
A) Could anything cause the TCS/OFF/SLIP lights to come on while changing an ignition coil - besides the potential use of a dynomometer?
B) Is it true that driving 75-100 miles would normally reset the onboard computer after replacing the Ignition Coil? If so, what would the likley reason be that the "check engine soon" is still on?
C) What should I tell/ask/demand the New York repair shop/inspection station to do?
Again, please be as specific as possible. Thanks again for your ongoing assistance
January, 17, 2011 AT 5:45 PM
The coil change has NOTHING to do with the TCS light being on, unless the shop did something, which makes no sense. The light should have been reset and if it is on, take it back and compel them to do the job you paid them for. Driving a properly repaired car that has had the check engine light reset, the repairs done in a complete fashion, and run within the parameters of what it will take to have the monitors run to completion should allow the test to run successfully. The state agency should be able to help in such a way as you're telling them what the problem is and having them respond. I dont think that I can tell you what that might be.
January, 17, 2011 AT 6:03 PM
I apologize for having to send you a followup, but I asked you to answer my questions
with specifics. I'll try again: A)From your response - I take it there is nothing, electic or otherwise, near the area of the the ignition coil replacement area that would cause the TCS lite to come on. Correct?
B) Perhaps I wasn't clear in my question (Is it true that driving 75-100 miles would normally reset the onboard computer after replacing the Ignition Coil? If so, what would the likley reason be that the "check engine soon" is still on?)They didn't reset the check engine lite... Saying I could pay another $125.00 if I wanted them to do so OR, as already stated, drive 75-100 miles...
C)Your response to A & B will asist me to answer "C" on my own.
January, 17, 2011 AT 6:16 PM
A) Correct B) Normally driving 75-100 miles would be more than enough. Paying ANOTHER fee for what they probably should have done to begin with, is not fair in my book. The fault that was set for the coil induced misfire should have been cleared, the car driven and scanned a second time to reconfirm the repairs were done correctly. For them to say give us another $125 is where the state regulatory fellows might help. I hope these answers are what you need.
June, 1, 2015 AT 9:06 AM
****Could be bad ECU! I had same problem it fixed everything for $100.
I had the same issue on my 1997 Q45 and read every forum for an answer. No where did I find the solution so I tried what the infiniti dealership and two other auto repair places suggested but wanted to way over charger for which was to replace all 8 spark plugs and ignition coils because "if one is bad the rest will go soon".
Still had tcs abs and check engine light on. So I cleaned then repined the connector from the wire harness to coil 6. Which was a pain in the ass but I was trying to avoid the next step of replacing the wire harnesses. Still no luck. About at the end of my pockets even doing all the work my self.
Finally I read somewhere about a different car that if you are getting a bunch of unrealted issues it may be a bad ECU. Found out they are only around $100 used so I gave it one last shot.
Completely fixed everything. Had to reprogram key fob but I can not explain how happy I was to drive my car running perfectly.
I know this is an old post but if anyone stumbles upon this I hope it helps you too!