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View Full Version : Removing NATS (Nissan Anti Theft System) from GU III 4.2TD Injector Pump



davejones
8th November 2014, 02:15 PM
In May this year up in the high country I stopped for a lunch break and when I went to move the truck (GU Series 3 4.2 Turbo Diesel) forward to level ground it wouldn't start. Bit odd I thought, and then it started a couple of tries later and I put it down to altitude & forgot about it. (Well actually it niggled as I didn't believe my altitude theory and I wasn't sure what it was, and I hate that...)

Few days later it did it again. Being in mobile range this time I called a mate who works at a dealership and asked.

"Is the light on the dash on?" he asked.

I told him my Dynamco immobiliser was off. "Not that one. The one near the windscreen." he said.

My response "What light?"

Turns out there was a light that had been buried under dash mat and MSA dash organiser for years that I'd completely forgotten existed. A solid red light was on as he suspected.

Going through the manual override process in the moaners annual worked and that confirmed I had a NATS problem. A bit of diagnostic mucking around over the next month ensued, as there appeared to be a relationship between the Dynamco immobiliser and NATS problem. After a while I disconnected the Dynamco and the problem was still there so it was definitely a NATS issue.

I started researching NATS issues on this and other forums and found that I had what seemed to be an infrequently experienced problem.

There are a couple of modules involved in NATS. The one causing the problem was the CSOLU - coded solenoid on the back of the injector pump. Essentially this black box recognises a signal from the system telling it the right chipped key is trying to start the truck and it provides power to the fuel shut off solenoid. It's very conveniently (sarcasm) located on the top back side of the injector pump. I understand why for security purposes, but if this problem develops with your 4.2, and as with mine gets worse, and worse (ie. more frequent) it could leave you in strife in the middle of the Simpson or up in the high country, and the recovery cost if you didn't/couldn't fix it would be huge. Not great.

It's located here (blue):
51450

I've seen a few posts about doing this on a few different forums now. Most involved bravery, long handled screw drivers and cold chisels, and belting the christ out of the little black epoxy thing until it's in a lot of pieces, while missing banjo fittings, injector lines and not damaging the pump itself. That wasn't going to be my preferred option. (There are pictures in a thread somewhere of a smashed CSOLU in bits.)

I called my mate Pete and asked if he wanted to come visit. He's a pretty handy mechanic and we've known each other a long time. He was up for a road trip. Turns out more than he thought as the hills got unseasonal October snow and he ended up doing a 900km trip to get the 450km here when he couldn't get over Hotham and had to return to the Hume and go the long way to Lakes Entrance.

While we were taking things out I decided to give the old girl a new radiator, water pump and hoses - particularly that little bastard under the inlet manifold.

We removed intercooler, radiator, fan, & water pump to get access to the front cover of the injector pump gears.

Pulling the battery and fuel filter out makes the next bits a lot easier.

Off with the inlet manifold, injector lines

Next it was off with the pump next to the injector pump. No timing issues to worry about on this one. There's a bolt/nut securing the injector pump that was impossible to get to without that pump coming off.

The harmonic balancer nut was too big for anything I or Pete had with us. Putting the truck in gear in 5th we moved it backwards until the injector pump timing gear ZZ & Z marks lined up, marked the top of the pump itself and adjacent mounting surface, so that when we put it back in it'd go back with the same pump timing.

Unplugging the wires on the pump (three connectors from memory, including the one hiding above the engine mount) the pump came out to the top side.

Keeping everything clean was important as you don't want to get grit or dust in lines going to injectors.

At this point we could finally get a good look at the culprit. The NATS CSOLU.

A couple of extracts found in another thread from the service manual show how it fits into the system.

5144351444

I'd heard horror stories about the tamperproof bolts they use to put it on the pump. I was expecting an hour or so at this point to get the box off the pump.

Turned out with the right tools it was a 10 minute job.

A couple of months ago, one of the guys at the local tool joint BJ Bearings talked me into buying a couple of these -
51445

With the right bit chosen and the instructions read the following photos show the result:
514465144751448

Once out the CSOLU was off in one piece. It's held on by a two piece clamp that locks around the body of the solenoid.

It was a simple matter after that to access the top of the solenoid by removing the clip on cap. Then you can undo the nut with an 8mm spanner and rewire the solenoid to direct 12 volt ignition switched power from the supply plug that originally fed the CSOLU.

I cut the plug off, extended the brown wire to a ring terminal and cable tied it to the pump brackets for strain relief. The pop on cap can be modified to fit a standard ring terminal. Bit of heat shrink and it was all good.
51449

It's a bit of a process, and it's a lot easier to have two people to put the pump back in and get the timing marks right (ESSENTIAL) as its not a straight cut gear, but it went back together in an afternoon after the pump was out by lunch time.

Made me wish (again) that I'd put a pit in my shed when I built it!

Make sure when you put it back in that you don't miss the connector hiding on the bottom of the pump. The lead for it comes from the main harness at the same point as the oil pressure switch and the connector is nearly the same but black.

Last chapter to the saga was that when I put it all back together and started it the engine light was on. Forum posts had referred to taping over the light on the dash and I didn't know if they meant the engine light or the NATS light.

I took it into my dealer mate and the fault code was related to the injector pump timing. I started wondering if the CSOLU had another role as a pick up of some sort. "There's a metal plate in the side of it that could be a pick up..." I think out loud.


Don't need to do this bit.... just part of the story.
He was unable to find anything useful out from Nissan, so I thought if I wired the CSOLU back in, in parallel with the plug that's now powering the solenoid directly I could remount it on the pump. I spent most of yesterday doing that. Not as bad as the original job but still three fuel lines off, those mongrel fuel line clamps to deal with, battery out to get to all of it, contortion, a mirror and some 6mm allen head bolts to replace the anti-tamper ones and it was ready to test.

All that and there's still an engine light on in the dash. Grrr...

But I found a plug we'd missed plugging back in during all that process. I couldn't for the life of me see where it went, and it was clean inside so it had to have been somewhere for the last 10 years.

With Yendor's help on here this morning I learned that there's a mongrel plug you can't really see on the bottom of the injector pump above the engine mount. Once reconnected, no more engine light.

Long and the short of it, NATS is a pain in the arse. Nissan should never have put it in a spot that could see a vehicle disabled in remote terrain. It's something that if I bought another 4.2TD I'd immediately get rid of despite the days work involved.

Even if you had to pay a grand because you couldn't do it yourself, you'd potentially save a $5000 recovery from the Simpson.

Thanks to Yendor again for his help.

I hope this has been an interesting read, and it helps someone else.

Footnote: Alden Grabbit-Pro's should be in every man cave. You'll never use another EZ out again. They are awesome!

Cheers

Dave

MudRunnerTD
8th November 2014, 07:10 PM
Good on ya mate, good write up. I have lived this and I did the wood chisel and lump hammer option. It took me 2 days to pluck up the courage to go and smash it off!! With the guidance of Nissannewby and Yendor from this forum I got the job done.

You may well have seen some of my pics in another thread. Was a crazy day! Yours was a very big job and I am not sure most would do it, I can't imagine how much Nissan would charge to fix this stupid thing!!

Thanks for sharing mate.

gubigfish
8th November 2014, 09:15 PM
Does anyone know if this is on all GU 4.2 models up to 2006?

MudRunnerTD
8th November 2014, 09:34 PM
Does anyone know if this is on all GU 4.2 models up to 2006?

Yes, if you have the flashing LED light in your dash in front of the driver you have NATS. "Nissan Anti Theft System"

The only warning I got was my LED light was staying on while driving. I only noticed it at night as it shines in the windscreen. Mine only failed once. At 1am after a 20 our day, in the Macdonalds Carpark while I stopped for Dinner with a fully loaded Tandem Trailer hooked up!! I called Yendor at 1am in the morning! He is a legend!

davejones
8th November 2014, 09:51 PM
There's a procedure in the manual for over riding the NATS system. I'd give page numbers but it probably varies from model to model.

Basically it involves turning the ignition off for a minute, then turning it to on for 5 sec, off, on for 5 sec, off, on for 5 sec, off, then starting the vehicle (from memory, it'll be close if not right.)

But I found it a bit hit & miss. Got me out of jail more than once before I did this. But at times changing keys or walking away and leaving the truck for an hour and coming back would start it too.

It's a god damn pain in the arse. No question.

If you have a NATS equipped truck, get rid of the CSOLU. It's a nightmare waiting to happen.

I think it's ironic that the best thing about owning a 4.2 is that there's bugger all electronics, and yet here's this electronic thingumy that is just waiting to give you grief.

I'm going to wire up the imobiliser from the Dynamco central locking & immobiliser again next. I disconnected it to make it factory standard to prove that wasn't part of the problem, but at least I can reverse that on the side of a track somewhere, and in the mean time still no-one can steal it. Not that it's much of an issue down here.

Thanks guys,

Happy to help.

DJ

davejones
8th November 2014, 09:58 PM
I think they are on 3.0ltrs too, but it's probably a similar exercise. Anyone know?

nissannewby
9th November 2014, 03:24 AM
Dave did you sent the pump timing? Or just try to get it as close to where it was when you removed it?

mudski
9th November 2014, 10:13 PM
So. As i have a TD42 sitting in my garage, in the hope that one day I will stop spending $$$ on my 4by so I can save to build this thing. This will be something I want to attend to before the motor goes in? The pump I have to isn't the electronic pump aswell. Not sure if this makes a difference. Still learning about these motors.

davejones
9th November 2014, 10:36 PM
Dave did you sent the pump timing? Or just try to get it as close to where it was when you removed it?

Just put it back as close as we could get it for now. Probably going to blank off the EGR and get it dyno tuned again I reckon. Hasn't been done since the exhaust went on five years ago or more.

Dave

davejones
9th November 2014, 10:40 PM
So. As i have a TD42 sitting in my garage, in the hope that one day I will stop spending $$$ on my 4by so I can save to build this thing. This will be something I want to attend to before the motor goes in? The pump I have to isn't the electronic pump aswell. Not sure if this makes a difference. Still learning about these motors.

4.2 pumps aren't electronic. Just the black box that controls whether to power the fuel shut off solenoid.

Unless you're installing the ignition to detect the right key & all the other NATS stuff I reckon you'd have to make this mod anyway if you are putting the motor in something else like a GQ or other truck.

nissannewby
10th November 2014, 01:15 AM
Just put it back as close as we could get it for now. Probably going to blank off the EGR and get it dyno tuned again I reckon. Hasn't been done since the exhaust went on five years ago or more.

Dave

Ok. It wouldn't hurt to get it checked with a dial indicator as the particular pump on yours can do weird things if the static timing is altered to much.

nissannewby
10th November 2014, 01:19 AM
4.2 pumps aren't electronic. Just the black box that controls whether to power the fuel shut off solenoid.

Unless you're installing the ignition to detect the right key & all the other NATS stuff I reckon you'd have to make this mod anyway if you are putting the motor in something else like a GQ or other truck.

Not quite 100% mate. The later model td42ti did have some electrickery on and a very basic ecu. This uses inputs such as engine rpm, #1 injector lift, tps, coolant temp and one of the output controls the tcv (timing control valve) which is the plug right at the bottom of the pump that you were asking about.

davejones
10th November 2014, 08:38 PM
Not quite 100% mate. The later model td42ti did have some electrickery on and a very basic ecu. This uses inputs such as engine rpm, #1 injector lift, tps, coolant temp and one of the output controls the tcv (timing control valve) which is the plug right at the bottom of the pump that you were asking about.

I stand corrected. Any idea when that started?

Guessing mine's affected. Which is disappointing as I really liked thinking it was simple...

nissannewby
10th November 2014, 10:18 PM
I stand corrected. Any idea when that started?

Guessing mine's affected. Which is disappointing as I really liked thinking it was simple...

Yes it's when they became inter cooled from factory that the electrics were added. They are very simple mate and aren't any less reliable then the older style. If something in the system does fail there is no limp mode or anything as such and the vehicle for the most part will be completely mobile.

drgtr
15th February 2018, 07:57 AM
To the blokes that had NATS issues. Im just trying to work out why it would fail and then thousands of ones out there are fine.

Did you guys do a lot of 4wding through mud or water?

MudRunnerTD
15th February 2018, 08:22 AM
To the blokes that had NATS issues. Im just trying to work out why it would fail and then thousands of ones out there are fine.

Did you guys do a lot of 4wding through mud or water?

No it's pretty random mate. When mine went it had not been off road for months and months. Since I did mine I have seen this and my thread bumped countless times. This happens ALOT. I have since fitted an alarm with immobilizer. Happy days

drgtr
15th February 2018, 08:33 AM
No it's pretty random mate. When mine went it had not been off road for months and months. Since I did mine I have seen this and my thread bumped countless times. This happens ALOT. I have since fitted an alarm with immobilizer. Happy days

Thanks Mate
I haven't had issues (touch wood) but I might get my mechanic friend to do it for me.

SO basically in a nutshell
Smash that black box open to get to the 1 wire protruding out. Then rejoin the middle loom wire to that one protruding wire?

I guess the scariest part would be hopefully not wrecking that 1 protruding wire in the process..

drgtr
15th February 2018, 08:34 AM
Also are we the lucky ones being td42t being able to atleast have this option? What do the 3.0 guys do?

MudRunnerTD
15th February 2018, 08:39 AM
Thanks Mate
I haven't had issues (touch wood) but I might get my mechanic friend to do it for me.

SO basically in a nutshell
Smash that black box open to get to the 1 wire protruding out. Then rejoin the middle loom wire to that one protruding wire?

I guess the scariest part would be hopefully not wrecking that 1 protruding wire in the process..

Here is my experience from the first post seeking advice on why the light was staying on to smashing off with a wood chistel..

http://www.nissanpatrol.com.au/forums/showthread.php?24666-NATS-Immobilizer-light-staying-on&highlight=IMMOBILISER+LIGHT

drgtr
15th February 2018, 08:43 AM
lol yes I read that thread.

All I can say is you are brave and secondly thankyou for sharing as that gave us knowledge to save a lot of money or if we are stuck.

Im going to fraser island next year. I wasn't even aware of this NATS problem so im thinking I might get my mechanic mate to do before hand for me.

davejones
15th February 2018, 10:57 PM
Thanks Mate
I haven't had issues (touch wood) but I might get my mechanic friend to do it for me.

SO basically in a nutshell
Smash that black box open to get to the 1 wire protruding out. Then rejoin the middle loom wire to that one protruding wire?

I guess the scariest part would be hopefully not wrecking that 1 protruding wire in the process..

There's no way I'd do it that way. Once you take the pump out it's so simple to run any of the new easyout style of screw extractors into the two screws holding the black box on and it comes off. Absolutely zero risk of damaging wiring, injector lines or pump. Not a lot more work either. Mark the position of the pump before you take it out and make sure it goes back at exactly the same spot so the pump timing doesn't change.

Dave

drgtr
16th February 2018, 07:44 AM
Hey Dave

I been told taking the pump out is really hard work though?

How long did it take you

Lionel84
6th September 2020, 08:28 PM
Hey Dave

I been told taking the pump out is really hard work though?

How long did it take you2 people it took a whole day, and one of them is a mechanic, as per Dave's concise explanation.

Cuppa
7th September 2020, 01:46 PM
Just read this, not realising until I saw mention of Yendor that this is an old thread. He was such a good resource to this forum! Yendor ... if you're out thee somewhere I miss you!

The read sure made me glad that us Dx owners don't suffer from the dreaded NATS. :)

davejones
7th September 2020, 04:48 PM
Sorry I hadn’t seen the earlier question but as Lionel said. Took a whole day to get pump in & out. About 2 minutes to remove the NATS black box with the Alden proGrabit. Few mintutes to tweak the wiring to bypass it. Most of the work was getting the pump out & back in again but given the grief the other methods could cause I’d do it this way again any day of the week.

Cheers 🍻 Dave

MudRunnerTD
7th September 2020, 05:13 PM
Sorry I hadn’t seen the earlier question but as Lionel said. Took a whole day to get pump in & out. About 2 minutes to remove the NATS black box with the Alden proGrabit. Few mintutes to tweak the wiring to bypass it. Most of the work was getting the pump out & back in again but given the grief the other methods could cause I’d do it this way again any day of the week.

Cheers 🍻 Dave

Wood Chisel worked for me.... :p