Earlier this year my wife had a situation where our '04 Nissan Quest wouldn’t “go” in drive. It would barely move along. Press the gas all the way and the engine would not rev and the car would barely go. It was “ok” in low, in that it would go as expected in low. Shut off car and restarted and problem went away.
Several weeks later, same thing happens. This time check engine light comes on. Again, turning off and back on again gets it going normally. Doesn’t happen most times. Seems to turn over a bit longer when starting (still less than a second or two) and problem happens when you shift into drive.
Take it into shop and engine codes correspond to service bulletin that suggests replacing both camshaft position sensors. Aren’t able to repro the transmission problem.
In the meantime, I locate service bulletin for this model year that describes more or less our exact symptoms (transmission starts in limp home mode, off/on cycle returns to normal). Fix is to replace transmission controller.
Talk to two dealers in area who have some vague memory of this problem but its been several years.
My question - are these two things related? Seems weird that the position sensor / check engine light only came on after several occurrences of the transmission problem. And now that I’m driving it, I can tell when its going to start up with the transmission problem by the fact that it cranks a bit longer before starting. And there’s sort of a jump when shifting out of park into drive and back that doesn’t happen normally.
Could the transmission misbehaving cause a falsely reported failure condition in the camshaft sensors or could camshaft sensors cause transmission control to start up in limp home mode?
I was thinking of fixing the camshaft sensors first and seeing if the problems shows up again with the transmission. (probably 10 cases in several weeks.)
Thanks in advance for your thoughts on this.
Since you have the service bulletin on the trans controller and 2 service reps that agree with it, AND it describes your symptoms to a T, I would replace it first. As for the error codes indicateing cam shaft sensors being bad, I would wait on this one. After repl. the trans controller, drive it for a while and see if any of the same problems or trouble codes reappear, if they do, most auto parts stores will read your codes for free, so you don’t have to pay for it at the dealership…
My ques for you is this: Your words–> Seems weird that the position sensor / check engine light only came on after several occurrences of the transmission problem. I agree, it seems slightly coinsidental.
So why are you chooseing to replace the cam sensors first? What am I missing?
Thanks for your response! In answer to your question -
- camshaft sensors are < half the cost (~$400 vs 800)
- engine codes are precise match for camshaft service bulletin.
- transmission issue is occasional (1x since it was in the shop…) and can currently be addressed by on/off cycle. Local shop told me that if the camshaft position sensors fail (or both fail?) then the car won’t start.
Transmission issue is symptom only - there aren’t any certain diagnostics. I’m the only one that has seen it, and the dealers and local shop only “agreed” with my diagnosis when I referred them to the service bulletin and my description. And I’ve only spoken with the guys answering the phones, not someone who has driven or fixed this issue.
However, your question does point out my flawed reasoning. IF the two are related, the camshaft issue happened AFTER the transmission problem started, so it seems way more likely that the sensor problem is caused by the transmission starting in limp home mode than the other way around.
Though clearly it could just be coincidence that they happened at similar times.
Also what I don’t know/understand is if the camshaft sensors are continually setting the error condition (check engine light) or it happened once and might stay off if I replace the transmission controller.
I really doubt either one of the problems could cause the other.
However, they could have an underlying issue causing them both, like a faulty ground connection.
OK I understand the $400 vs. $800 dilema. I’m glad I’m not makeing the decision.
I was baseing my thoughts on paragraphs #1 #2 #4 #5 #8 in your original post and your statements: "the trans worked ok in low gear but not in drive, and the fact that you had 10 cases of the trans failure in several weeks time. I think all of that is the trans controllers fault.
Compare those 10 trans.failures to only 1 error code for the camshaft sensors and that’s why I was leaning towards the trans controller being the first choice for replacement.
Re: camshaft sensors (trouble code light) I agree there is a problem with them too, and they are probably causeing the starting problem, but you said the engine only takes a second or two longer to start when this occurs, so on my car/truck that would be a minor inconvience. I live with those all the time when money is an issue. lol
Like I said, I’m happy I’m not makeing the decision on which to buy first
Are the $400 and $800 prices for parts AND labor?
(Circuitsmith brings up a good point. If the two are shareing an underlying cause?)
If you could get a look at a wireing diagram and find a common ground, or power supply that they both share, maybe it is loose. Also you could check the body grounds, engine to chassis, chassis to body, etc. They are often overlooked and are never checked during routine maintanance services. Electrical current can usually find a path through body bolts etc. Still there is a reason the factory puts them on there. I think I would do this FIRST before you spend ANY money.
Most public librarys have a full selection of manuals in the refrence section. You can’t check them out, but they let you photocopy the pages you need. Copy the wireing diagram that applies to your EXACT model. You might copy the Trans. section and read about the controller, and likewise do the cam sensors pages too.
keep us posted
Did this ever get fixed? Any conclusive answers to the problem?
I have a 2007 Quest that is now in the dealership for the 5th time for the exact same issue.
They’ve replaced both cam shaft sensors.
They’ve found issues in the wiring harnesses and repaired those.
They’ve replaced the transmission itself.
I’m into this repair job for close to $5,000 and it’s still not fixed!
^&^%&(^((*
I’m replying here via email because it looks like its been 9 years and the email I received this with is no longer found in the membership login!
Anyway, sorry to hear that your Quest sucks. Our 2004 did too. Spent over $5k on repairs right after warranty was out. I just got some paperwork to file with a class action and get my 10% back. But that was for a timing belt/chain at 60k miles, not this issue.
I did have the camshaft sensors replaced. I believe that fixed this issue, I don’t recall having to replace the transmission controller. I will look through our paperwork and update this if I find otherwise.
My wife just traded it in a few months ago for an Audi Q7 which she loves. The Quest was more functional and a great vehicle if it weren’t for the design flaws and support issues.
Good luck.
I really appreciate your reply. Thank you. I’ll let you know if they ever figure it out at the dealership.