Post Reply 
 
Thread Rating:
  • 0 Votes - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
maxima evap system leak and knock sensor
02-16-2011, 07:15 AM
Post: #11
RE: maxima evap system leak and knock sensor
Ok, I think I have a plan here. The book says I can check the sensor by removing the elec connector and applying the leads from my multi tester to the terminals on the sensor. If it shows continuity- the sensor is good, if it shows an open circuit- the sensor is bad.

So, tell me if this plan makes sense to you- I hook up a timing light and tap on the manifold and if I see the timimg change then I know that the sensor is working and to look elsewhere for why the sensor is sending the code. That eliminates me having to try to dig the sensor out from under the manifold.

If the timing does not change, then I will take the sensor out and check for continuity. If the sensor tests bad- problem solved, if the sensor tests good- then I start checking the wiring and connection.

Does this plan makes sense to you? would you do anything different? Sorry for all the questions, I just want to make sure I do this all in the most efficient manner in order to find the actual problem and not waste time, money, and effort.

Thanks Rupe and Garner for sharing your knowledge with us all, it really helps to ease the stress on some of these problems!
Find all posts by this user
Quote this message in a reply
02-16-2011, 10:58 AM
Post: #12
RE: maxima evap system leak and knock sensor
Sounds like a plan... and a decent one at that!

Does you book break down the wiring diagram enough to do a continuity test on the harness from the sensor to the ECM? If not I recall Nissan was fairly good at color codes on the wiring so perhaps you can pick it out that way.

The only other thing I can think of at the moment is the EGR hung up at some point (frozen?) and that allowed a slight ping long enough to set a code. There are other "normal" driving conditions that can set codes too so it would'nt be the first time.

One such intermittent code that comes to mind was a rich condition that cropped up on an Olds wagon years ago and after some questions it was always while hauling a load up a long hill. IOW, almost wide open throttle for longer than 15 seconds. Turns out the ECM ignores this condition at wide open throttle (WOT) but less than that is supposedly abnormal. The guy thought he was doing himself a favor by going light on the gas and not allowing the trany to shift. In the meanwhile the ECM thought otherwise. The warning was actually in the owners manual under trailer towing. (go figure)
Find all posts by this user
Quote this message in a reply
02-17-2011, 07:07 AM
Post: #13
RE: maxima evap system leak and knock sensor
Looked at the wiring diagrams, they are actually pretty darn good. So I'm going to proceed on course. Will probably take a couple days to get through everything as I have a very small window of time in the evenings.

Will keep you posted as to my findings over the next couple of days and hopefully by the weekend we'll have this one solved!
Find all posts by this user
Quote this message in a reply
02-17-2011, 08:40 PM
Post: #14
RE: maxima evap system leak and knock sensor
This may be a silly question, but what is the procedure for hooking the timing light up when I have individual coil packs and no plug wires?

If I use the kind with the spring and clamp, I wont be able to go from the boot on the coil to the plug without touching the sides of the hole in the intake and arcing.

If I use a light with the clamp that goes right onto a plug wire, Would I simply clamp it onto the wires going to the #1 coil pack? Since there are more than one wire going to each coil pack, will it mess things up?

Tried searching the web for this and am getting conflicting and rather confusing info!
Find all posts by this user
Quote this message in a reply
02-17-2011, 10:17 PM (This post was last modified: 02-17-2011 10:19 PM by Rupe.)
Post: #15
RE: maxima evap system leak and knock sensor
Hmmmm, I completely forgot about that! The best way to see the timing in this case is with a scanner that will show what the ECM sets, although with a sharp eye you may see a slight variation on a tach for a second or so. It will be quick so you have to watch for it. A full function scanner may have a screen for the knock sensor.
Find all posts by this user
Quote this message in a reply
02-21-2011, 07:07 AM
Post: #16
RE: maxima evap system leak and knock sensor
I'll have to check with the parts store, see if they have one on their loan a tool program. I don't believe they do though.

I may have to just dig down there and get the sensor out and do the continuity test. I've been busy from dawn to dark the last couple of days, so I have no good things to report on this project. I should be able to get back to it now though.

Thanks Rupe.
Find all posts by this user
Quote this message in a reply
02-26-2011, 05:17 PM
Post: #17
RE: maxima evap system leak and knock sensor
Problem solved! The knock sensor was evidently bad. As I did not have access to an ecm scanner (I needto get a cable and download the software) I just tested the sensor with an ohm meter.

The Haynes repair manual says to check for continuity at the two terminals of the sub-connecter. I misread it and went ahead and removed the sensor and checked at the terminals on the sensor itself and it tested positive as did the new one. So I re-read the book and realized my mistake. Probably has something to do with only one wire going from the sub-connecter to sensor and one terminal of the sensor being plugged into an empty socket of the connecter.

So I put it back on and checked at the sub connector like the book said. At this point, continuity was not indicated and the book says to replace sensor in that event. So I did, and the vehicle is running well and my scan tool says there are no codes present.

On a side note, if anyone needs to replace this sensor and they have a Haynes manual...you do not need to remove the upper and lower intakes as the manual says. The sensor can be seen and accessed from the opening just below where the air intake and throttle linkage are. You need to either have small hands or suffer numerous scrapes and cuts like I did, but it sure beats buying new intake gaskets.

Once again, Thanks Rupe and Garner for your advice!
Find all posts by this user
Quote this message in a reply
02-26-2011, 07:02 PM (This post was last modified: 02-26-2011 07:06 PM by Rupe.)
Post: #18
RE: maxima evap system leak and knock sensor
Glad to hear the final resolution!

BTW, I have small hands (no jokes here guys) but they don't bend like they once did. At any rate, it's also good to hear you can get in there without the extra work.
Find all posts by this user
Quote this message in a reply
Post Reply 


Forum Jump:


User(s) browsing this thread: 1 Guest(s)