Crank Shaft Posisition Sensor

[jims-terrano]

Nope it don't stall (yet), didn't get chance to clean mine like I wanted to. Need to trace wiring as I'm sure it goes to a connector on the top of engine. Would like to give all contacts a good clean too.

Jim T

 

[rayf3262]

ok, so I had a crappy day Maverick wise. I had to use it for work see, a trip to Dewsbury then a trip back to HUdds. Upon entering the town centre the mil light came on and was a bit juddery, then stalled when I pulled over. grrr. Was ok after that, 1.5 hours later.

REALLY need to know a fix for this, I get code 47 like Jim, but I changed my sensor for another used one, no difference, is it possible that the used one is also faulty??? Is there a test you can do on the actual sensor?

like Jim, I need some help, because I cant trust the car with randmon problem like this!

The sensor is a coil with a magnet in the centre, the coil should read on pins 1 & 2 around 900 ohms with a meter. There is not much to go wrong!
The only way to test is for certain is to use an oscilloscope and look at the output from the sensor with the engine running.

The sensor has 3 connections that terminate at the ECM, the 2 signal connections are on ECM-P344 to sensor P2 & P331 to sensor P1
The third connection is a shield/ground on ECM-P332 to P3, check these for continuity between the ECM and sensor connector.

Question: does the tacho behave at all erratic when the fault occurs?
R

 

[clivvy]

will attempt to try your suggestions, as for tacho, behaves normally!

 

[makeitfit]

Just a quick spanner in the works guys :doh
As I said earlier I've had three of these and checked resistance and they were about 1400 ohms ish as best I can rember. I used one that was on my mates car and running fine, put it on mine and no difference to the running:augie
Put another s/h one in stopped the mil but still about 1500 ohms:doh
Ocilloscope thing was done by Mr diagnostics and was doing a nice square wave form thing, so we're none the wiser
Wish I could warrant "trying" a brand new one to see if it's any better:sly

 

[clivvy]

Just a quick spanner in the works guys :doh
As I said earlier I've had three of these and checked resistance and they were about 1400 ohms ish as best I can rember. I used one that was on my mates car and running fine, put it on mine and no difference to the running:augie
Put another s/h one in stopped the mil but still about 1500 ohms:doh
Ocilloscope thing was done by Mr diagnostics and was doing a nice square wave form thing, so we're none the wiser
Wish I could warrant "trying" a brand new one to see if it's any better:sly

Yeah, I can see what you are saying, and I do get the impression both mine and Jims "code 47" isnt as simple as changing the sensor. So what fixed your issues then?

 

[makeitfit]

Yeah, I can see what you are saying, and I do get the impression both mine and Jims "code 47" isnt as simple as changing the sensor. So what fixed your issues then?

Dont know yet, must get round to taking the I/C off and sorting the No1 injector. Then still to do the EGR, then remove the throttle flap in the body, etc etc:augie Blank off asst vacuum pipes and stick my bloody LPG up it:sly
Come to think of it, I'm amazed it goes at all:lol
Best not use mine as an example :augie

 

[clivvy]

So...you still have the same issue as us, but yours is still running ok?

 

[makeitfit]

Well I dont get stalling, but it's a slug below 1700/1800 rpm :augie
But like I said it's not there for long I just plant the boot and all is well:naughty

 

[rayf3262]

Just a quick spanner in the works guys :doh
As I said earlier I've had three of these and checked resistance and they were about 1400 ohms ish as best I can rember. I used one that was on my mates car and running fine, put it on mine and no difference to the running:augie
Put another s/h one in stopped the mil but still about 1500 ohms:doh
Ocilloscope thing was done by Mr diagnostics and was doing a nice square wave form thing, so we're none the wiser
Wish I could warrant "trying" a brand new one to see if it's any better:sly

That's interesting, so the jury is definitely out on this one...
I wonder where the scope was attached? at the sensor or at the ECM?
would make big a difference if there was a wiring/connector issue...

A variation I can think of, that might exist between different sensors is the strength of the magnet in the sensor, they do loose some permeability over time, so an old one may well be somewhat different to a new one. The manual also states "do not use a sensor that has been dropped or knocked", this will also alter the properties of the magnet!

Re: the problem only occurring when the engine is good and hot (15 miles..or so), magnets do temporarily loose strength when hot and regain it when cool, this a characteristic exploited in Weller soldering irons with the "Magnastat"

R

 

[clivvy]

Some interesting points there. What I don't understand is how come this problem isn't more common in older vehicles? The point about magnets temporarily losing strength when the engine is warm is interesting, and consistent with what's happening here also. My plan is this-find the ECM and test the wires, if good, change the sensor, if bad...er... And report back here!! I wish there was a simple answer, I suspect jims issue may deteriorate like mine did, when my issue became apparent, car never stalled, now it does! I only seem to get limp home mode when driving, and foot on accelerator, if I allow idle, and the mil comes on, it shudders then stalls!

 

[shadowbroker]

what would the part number be for the sensor? there are no numbers or anything on mine. mine is near the fan at the front, and has the greyish connection, 3 wires. i did get one on ebay but it didnt fit, it had a black connector.

 

[jims-terrano]

Dunno cos it was 3 years ago when I bought mine. However check out this thread as it may well be a cheaper alternative.
http://www.nissan4x4ownersclub.com/forum/showthread.php?t=19354

 

[revolvor]

Yes a tenner sorted mine out, I had to cut and solder the wires, could possibly look at mine and tell you what wires were soldered together, I cannot remember without looking, I have been to bed since I did it !

 

[AD Ent]

Yes Please! :clap This could be a new Workshop Download. What spacer to use and what wires to join.