At wits end!!

[jscottnjs]

Hi all,
I have a 2012 D40 that has had the code P102b code for over a year. I have taken the car to Nissan dealer's, mechanic's, everywhere. The sensor has been changed twice, the car has even had a new tune to reduce the boost spike it was having. The last time this code came up the EGT temp was only 220c no where near the extreme's. The car threw this code while driving up hill at 70kms and felt like the car was labouring and taking longer to change down a gear, almost to the point of putting my foot to the floor before it changed down a gear and that's when the code came up. Does anyone have any ideas please

 

[MANNING]

The sensor has been changed twice..

which sensor mate?

 

[MANNING]

P102B code possible causes
Faulty Exhaust Temperature Sensor Exhaust Temperature Sensor harness is open or shorted
Exhaust Temperature Sensor circuit poor electrical connection

^^ CUT FROM HERE <--

 

[jscottnjs]

The EGT sensor it's self, I have seen this page but really hoping I do not have to start chasing wiring around the car.

 

[GunMentalGrey]

“circuit poor electrical connection”

If the sensor is new ...

 

[MANNING]

“circuit poor electrical connection”

If the sensor is new ...

sensor could be new with ****** wiring?
im not sure, just trying to be of some help..
is there not two sensors for those?
does the model have a dpf?

 

[OldManBeard]

Why was the sensor changed twice? Are you even sure the correct sensor was changed? Some of the information I've come across for this group of sensor codes can point you to the wrong sensor. Anyway, it all sounds to me like an act of desperation, rather than something resulting from a proper investigation into the problem. If I had someone suggest to me that I should replace a sensor twice with no change of result I'd be going elsewhere in future. The odds of the problem being a faulty original sensor, which is then replaced by a faulty new sensor is incredibly low. Not impossible of course but about as likely as winning the top prize in the Lotto.

The code seems to clearly point to an electrical problem. As the sensor (assuming it is in fact the correct one) has been replaced twice I think we can safely assume it's not a faulty sensor otherwise it would mean you've had three faulty sensors in a row. Unless other work has been carried out, which could have upset the wiring elsewhere, the problem is almost certain to be under the vehicle, so there's just not that much wiring to be checked. Start with the connector at the sensor. Is it a tight fit on both pins? Is there any sign of corrosion? Are there any indications that the wiring has been pulled on or otherwise stressed? If you can't find the problem yourself I'd suggest getting an auto electrician to check it, rather than a mechanic.

 

[jscottnjs]

sensor could be new with ****** wiring?
im not sure, just trying to be of some help..
is there not two sensors for those?
does the model have a dpf?

Thank you, it is not a DPF model, I think I will be having a look at the wiring. Is there a tool I can use to assist?

 

[jscottnjs]

Thank you for your reply, desperation is an understatement lol. The car has been to 3 different Nissan service centers with each one of them guaranteeing they know what the problem is. The car has also been to a Nissan specialist. I will go and inspect the wiring near the sensor, is there a tool I can use to inspect or make sure the wiring is as it should be? Or even to help fault find? Again thank you for your reply.

 

[OldManBeard]

Thank you, it is not a DPF model, I think I will be having a look at the wiring. Is there a tool I can use to assist?

I believe the non-DPF models only have one sensor so that at least eliminates the problem of replacing the wrong one. Do the simple stuff first, as there's a possibility that could save you further expense.

The only tool available to the average person for this kind of work, other than their eyes and fingers, would be a multimeter which would allow you to test for open circuit or high resistance. The problem is that you need access to both ends of the wire to be tested. If you know somebody who does computer network cabling you may be able to borrow a signal injector/tracer kit from them, which can be used from one end of the wiring (just don't turn on the ignition while using it). I've used them in the past to find faults along a wire but it can take a delicate ear to detect the change in the signal if the break is very small.

 

[jscottnjs]

I believe the non-DPF models only have one sensor so that at least eliminates the problem of replacing the wrong one. Do the simple stuff first, as there's a possibility that could save you further expense.

The only tool available to the average person for this kind of work, other than their eyes and fingers, would be a multimeter which would allow you to test for open circuit or high resistance. The problem is that you need access to both ends of the wire to be tested. If you know somebody who does computer network cabling you may be able to borrow a signal injector/tracer kit from them, which can be used from one end of the wiring (just don't turn on the ignition while using it). I've used them in the past to find faults along a wire but it can take a delicate ear to detect the change in the signal if the break is very small.

Thank you I will take a look tonight

 

[Old.Tony]

The other thing to do is - believe it or not - clean your battery terminals, check continuity of the fusible links (especially while you "tap" at the terminal clamp with a small weight like a screwdriver handle, not a hammer!) and make sure the big cables going to the alternator/engine block are secure and clean.

More than one electrical gremlin was caused by a poor connection. Sometimes that's a crushed cable, sometimes it's a pressure washer pointed at the engine bay (just don't do it) and sometimes it's age/fatigue/corrosion.

Good luck with the search.

 

[jscottnjs]

I believe the non-DPF models only have one sensor so that at least eliminates the problem of replacing the wrong one. Do the simple stuff first, as there's a possibility that could save you further expense.

The only tool available to the average person for this kind of work, other than their eyes and fingers, would be a multimeter which would allow you to test for open circuit or high resistance. The problem is that you need access to both ends of the wire to be tested. If you know somebody who does computer network cabling you may be able to borrow a signal injector/tracer kit from them, which can be used from one end of the wiring (just don't turn on the ignition while using it). I've used them in the past to find faults along a wire but it can take a delicate ear to detect the change in the signal if the break is very small.

So this is what I found on the sensor wiring, looks like the heat sheild has been nicked. Perhapps the wire has also been nicked or the heat is getting to the wire and causing a high egt code

 

[Old.Tony]

That looks like it's seen some serious heat. Have you popped it out to have a better look at it? The sensor itself will look fairly blackened, but that's to be expected considering where it is.

 

[jscottnjs]

That looks like it's seen some serious heat. Have you popped it out to have a better look at it? The sensor itself will look fairly blackened, but that's to be expected considering where it is.

I have not got it out yet thjs is the new sensor, well avout6 months old. Do you think I should swap the location of the sensor to where the egt probe for my gauge is? It would move the sensor about 8 inches away from the current location

 

[Old.Tony]

I assumed it was the DPF sensor (my car doesn't have EGT sensors). I've never given any thought to relocating them- that's always a possibility, I don't know if it will affect the ECU's calculations though. If it does, I can't imagine it would be by much.

 

[jscottnjs]

Ah ok, mine is a non dpf model

 

[Been a while]

Buy a multi metre and read the manual.. it will show you how to check sensors and check for continuity ... $20 superbleep multi meter and you're away!

Once you read the manual you'll see it can be multiple issues that can throw one code, that code may lead you to a sensor but it may be another part on that circuit letting the team down.. its a Nissan thing! But I strongly suggest reading the manual....

And be very gentle working with automotive wiring, it heat cycles and becomes brittle! ESPECIALLY near plugs and sensors!

There's a section in the manual for code tracking and testing sensors! These things have multiple earth's too that can cause issues! Check earth's... good luck...

 

[jscottnjs]

Thank you all for your suggestions, I am off to buy a multimeter and also continuing to try remove this sensor. Of course these are placed in the worse places!!!

 

[jscottnjs]

Hi everyone, so I bought a multimeter (auto ranging) disconnected the egt sensor but left it screwed into the car. Continuity testing gave me no readings only open circuit and resistance testing was 71.2k and 136.7 (it was hard to keep the probes on) big question does this mean anything? has the sensor had it? If so is this why I would get intermittent codes every now and then?