D40 Fuel Economy

[bigfluffys]

Guys, I'm compiling all of these tips into a single set of instructions with links back to the original posters' posts so that credit can go to those who provided the info. I think those who want to give it a go should and please post feedback in here so we can make this accurate. Also, if you find it difficult to follow, send me a pm and I'll do what I can to clear things up.

Here it is, so far:
_____________________________________________________________________________
Original post: Exhaust mod with DPF page 2 post 27081

Modifications to refine procedure are in bold.

D40 ECU RESET PROCEDURE
To carry out the reset do the following:

Warm up the vehicle to normal operating temperature then turn the vehicle off.

Turn ignition on so all dash lights come on.

Wait 3 seconds.

PUMP accelerator pedal 5 times within 5 seconds....

With foot now OFF accelerator wait 7 seconds...

After 7 seconds press and hold down accelerator pedal for 10 seconds...

After 10 seconds the Engine Management Light will start to flash, at this point remove foot from accelerator.

The Nav is now in diagnostics mode, so let the EML flash for a bit. Then press and hold the accelerator pedal down for more than 10 seconds - this will then reset ECU and fuel pump etc and put them into learning mode.

Holding the accelerator for that long ends the procedure.

From D40 Fuel Economy page 26 post 36741:
DO NOT TURN THE IGNITION OFF. Take the vehicle for a nice gentle drive, go through all the gears and then shut the vehicle down to finish the learning process.

NOTE: When the EML light is flashing, this is listing possible fault codes... so if you know how to read the fault codes or know the sequences then you can figure out any possible faults with your Nav with out getting the dealer to do it!!

From D40 Fuel Economy page 26 post 36627:
Seeing 1 set of 10 slow flashes followed by 3 sets of 10 flashes fast means there are no faults found or stored.

Hi had my fuel sucking o8 king cab back to nissan again, they have checked everything (so they tell me ) all is well so they say , but they cannot explain why my car uses 50% more fuel than anyone else i know with the same year car ,either auto or manual , current useage is 16-17L/100 in town , and 14-15L/100 on highway , also its quite flat around here and im not working car hard at all as im too frightened to use too much fuel , had a trip with camper on the other day used 56L for 239km , great economy !!! this is the worst ive ever had to date , so as it stands im up the creek , nissan say its fine i say its **** , next idea anyone ??

 

[Aussie Frontier]

Last tank of fuel was 12.3 l/100kms using Optimax 95.

As to resetting the ECU ( now this may upset some) I have found the easiest way is to disconnect the neg terminal off the battery and touch it to the pos terminal. Now this is not shorting anything out but it is discharging any capacitance that may have built up in the truck . The system will reset itself if you leave the battery disconnected for a few hours some say up to 12. Now please be aware doing this will reset all codes on the truck including your radio so b4 you attempt this make sure you have your security codes etc. This is the fastest and easiest way to do the reset however it does reset clock and radio etc.

 

[KraftyPg]

Am I missing something? Disconnecting the battery for a few hours (or up to 12) is the fastest and easiest way to reset the ECU? The way Tony suggested took 30 secs.

 

[Aussie Frontier]

Ok the disconnecting thing is fast if u touch neg cable to pos. The 12 hour bit is if you dont want to do the touching of neg cable to pos terminal. The 12 hours is to let things discharge normally.

 

[KraftyPg]

Still reckon sitting on your arse in the drivers seat with a key for 30 seconds is quicker and easier than removing a battery terminal and reconnecting it. However I might try the same theory next time my PC needs a reset, touch the black and red wire and zappo PC all refreshed...12V arcs are for whimps!

 

[Aussie Frontier]

so you play with PC's as well eh. Never had to fully reset a bios before then?
Only way to properly do it is to remove the battery from the motherboard and try to start the PC so it fully flattens the charge on the motherboard and forces a full reload of the firmware.
Same thing really. One is a software forced reload of the bios that never really forgets all its learned and the other forces a full reload of the base codes .

 

[KraftyPg]

Disconnecting a PC battery in no way arcs the terminals but if you think thats the only way to fully reset a PC bios then I'm glad this convo is ending here.

 

[Aussie Frontier]

No what I said was that the motherboard had to be fully discharged . The touching of the ned cable to the pos cable does not short out anything . It meerly discharges any charge that may be residual.

 

[Old.Tony]

I'd be a little wary of touching the two battery leads together after removal from the battery, because if there is any residual power in the system, it could run through to the ECU and while the ECU will have protective diodes (normal or zener) on it to stop transient voltages from spiking the unit, a decent shot from a charged capacitor will destroy the little surface mount diodes and that'll stop the ECU altogether.

Anyone that's worked on computer innards (perhaps PC techs, but mostly minicomputer and up) would know that as little as 5V of stray power can destroy CMOS devices. If there were no sequence available to sit in the driver's seat and perform the reset, I'd rather wait 12 hours for the discharge than wait 4 months for a new ECU to come from Spain!

Which raises another alternative, pointed at by both of you guys. If you "flatten" the power in a PC by removing its power source and trying to turn it on ... do the same thing in your car. Disconnect the battery and turn on the ignition, ECU will try to start and will consume the residual power. Goal achieved with zero damage.

On a final note, I want to disclaim myself as being the source of the procedure, I am only the compiler of the information. Others, as I described in my post here are the true sources of this useful information.

 

[KraftyPg]

The bottom line is that arcing two terminals no matter what the source or how powerful can always have an element of risk but if your happy to suggest it as a viable way of doing something that can be done in 30 seconds with a key or something that can be done in 12 hours with the removal of the battery then thats fine by me I'm just glad your not my mechanic.

 

[Aussie Frontier]

Tony what your saying is essentially correct however what the touching of the neg cable to the pos is not shorting anything in fact and it is only extremely small voltages we are talking about here. All it is doing is making sure that the volatile ram in the system is cleared completely forcing the firmware to fully reload itself.By touching the terminals together your not shorting out the system , your making sure there is no potential difference in the system that could possibly retain anything in the volatile memory.
The method of ignition switch and pedals essentially is only sending a software reset signal to the ECU so it may or may not totally reset the ECU.
The 12 hour time is only a time that is meant to be long enough in theory to let the system discharge itself via its own leakage .In most cases its been the case that just disconnecting the battery or pulling the fuse to the ECU is enough to reset the ECU. The problem that has been occurring in the past few years is the fact many cars have numerous ECU like the Navara/ Frontier do.Its the extra ECU systems that can in fact be causing the issues so a full reload will make all units reload the firmware and revert back to factory settings.

I have a question
If the ECU is fully reset then why would it then show you the error codes as if the ECU is fully reset it wont have any errors unless you have a faulty sensor etc.
The sequence may in fact reset back to factory options but not clear the volatile memory where the error codes are stored. Who really knows what that sequence does.

Just for those who are asking yes this is what I do on my vehicles and so far have had no issues.I reset my ECU when ever I make any changes like a different grade of fuel or even cleaning the air cleaner filter.

 

[fozzinoz]

Hi - I've had mine 3 weeks and getting about 10.3/100km so far

 

[Jardsoooo]

My D40 RX has done a couple of thou k and a country trip this weekend returned 355k for 33 litres inc doodling around the country township. Not too bad but I do drive like I have a bowls hat on the back ledge.

 

[Old.Tony]

My D40 RX has done a couple of thou k and a country trip this weekend returned 355k for 33 litres inc doodling around the country township. Not too bad but I do drive like I have a bowls hat on the back ledge.

9.295 LPHK. Nothing to sneeze at!

 

[Aussie Frontier]

Currently running 12.9 from the V6 Petrol around town on Optimax 95

 

[Martin'sD40]

.......... All it is doing is making sure that the volatile ram in the system is cleared completely forcing the firmware to fully reload itself.
................
in fact be causing the issues so a full reload will make all units reload the firmware and revert back to factory settings.

.

Hey Aussies , I have one for you

If what you say is true about the re-flashing of the firmware where it resorts back to its true factory settings , why do any of us have the need to do the sequence ECU code clearing when your way might just be a faster way to remove any codes that don't get cleared doing it the other way

As for your other question why are there still codes stored ? This often happens as soon as you turn the ign back on ,Air con, knock and temp sensors log codes as soon as the ign is turned back on

back to the discharging of any residual power that could remain the system , yours is a Petrol D40 and there should be no need to reset anything.

Where or how did you find out about clearing the codes and forcing the ECU to go back Factory defaults ?

Interesting to hear about the chattering diesel injectors and resetting the codes during colder times to quieting them down , will have to give that a try as well , I did notice when I blocked off the EGR that the chattering was no where near as loud as in the past

Does anyone know of a super good Elec Diesel specialist around Sydney at all ?

Cheers Mate, Marty

 

[Aussie Frontier]

Hey Marty
It was from ClubFrontier as they have pretty much the same truck as mine.I have found that running different fuel or even when I changed air filters did fix a few things. Silly stuff like when I changed air filers the engine was running hotter till I did the reset then back to normal she went .Of all things I find it works when I change my wheels to a different size .Basically by resetting the ECU I cut down on the relearn time.
The ECU in the trucks are pretty much purpose built Computers. I have been working on computers for 20 years now and also used to do custom fuel injection. The factory firmware or basic code is where it all starts from and then the ECU learns its surroundings so to speak.
Our Fuel Injection business basically worked on writing our own settings for the GM 808 ECU which was the stock ECU from just about everything GMH put out from the 4cyl to the V8. We were able to program them to run on everything from a single cylinder bike engine to a V8 blown beast.
The logic behind it is that the volatile memory in the ECU relies on the fact that the battery keeps it powered. if that memory looses its power then it looses all data stored.
on earlier cars with single ECU it was easy to reset the ECU by simply pulling the fuse that fed power to the ECU and basically wipe all the volatile memory.
Now on our vehicles we have more than 1 ECU and a heap of other electrickery. Now these various items could create a sort of capacitance that could in theory keep the volatile memory powered for a few hours. the guys in the states were saying up to 12 hours. The mechanics in the Nissan workshops were basically leaving the battery disconnected overt night to ensure a full reset.
Now when you run the sequence with pedals and switches etc your actually writing a form of code to the ECU. When the ECU sees the code you create it then reacts by doing a software reset. however it doesnt turn the power off to the volatile memory so there is no way to know if it really does loose all its learned memory.

Think of it this way
imagine the ECU as a headlight globe. Touching the + and - of the globe to the + and - of the battery and you create a ciruit and the light is produced. if however you touch both + and - of the globe to either terminal on the battery and nothing happens at all.
However if you have a big car stereo with a smoothing capacitor then yes you have a physical storage device or in fact a battery connected to your system . touching the leads together then will cause a reaction as it will be discharging a large storage device .
In standard form there is no real capacitance in our system that connects directly to the + and - of the battery. We will have very small forms of charge built up in things like the stereo etc .
In short its a software reset compared to a hardware reset .

When disconnecting your airbag does it not say to wait a set period of time before knowing your system is disarmed. The system that drives the airbags is yet another electronic controller unit or ECU .The wait time is to ensure the system is fully discharged so will not false trigger.
I havent ever done it myself but if worried you could always put a volt meter across the leads to see whats left and watch it discharge .

Just think the code you write with the pedals and ignition etc could be telling the ECU to reload a pre-set set of code thats not actually a reset but change it to a different mode.The amount of code the ECU can hold compared to how much it does hold generally is huge. We used to load 3 to 4 complete programs onto a single chip and used a code sequence to swap programs.
I had a 2 door XB Hardtop with injected blown small block running custom injection and full electronic programmable coil packs . I could literally change the program by a set of switches and restart the car so could go from a mild street program to a very thirsty power program for the strip.

 

[norts]

d40 series manual nissan navara

Hi guys,

I am new at this forum. I have my navara just about 1 month and I get approx. 540k's to three quarters tank. I live in Trinidad and would lioke to know what is the best fuel additive and engine oil I can use for my van.

My brother is the agent for SWEPCO oil lubricants here in Trinidad. But i feel as though everyone is saying that their product is the best because they are trying to make a sale.

I need some advise..please
both for fuel additive and type of engine oil

regards, chris

 

[Old.Tony]

Hi guys,

I am new at this forum. I have my navara just about 1 month and I get approx. 540k's to three quarters tank. I live in Trinidad and would lioke to know what is the best fuel additive and engine oil I can use for my van.

My brother is the agent for SWEPCO oil lubricants here in Trinidad. But i feel as though everyone is saying that their product is the best because they are trying to make a sale.

I need some advise..please
both for fuel additive and type of engine oil

regards, chris

Welcome to the forum, Chris!

11.1 litres per hundred kilometres (LPHK) is not a bad result for your car, especially as it's fairly new!

You need a diesel oil that suits the temperature range for your region. The best coverage would be a 5W30, in Trinidad you might be able to use a higher weight oil without too much trouble. It has to be a diesel oil, and should be "low ash" - JASO FD is preferred, but FC ought to be okay as an absolute minimum.

Fully synthetic is fine too, as long as it is low ash. Diesel engines produce lots of blow-by and through the PCV some of that oil is combusted. It also has to run through the turbocharger, so it can't be a really heavy oil unless your ambient temperatures are high enough.

 

[Martin'sD40]

Aussie that was a good read , kinda reminds me of the factory traning we used to do when i was on the floor with Nissan 30yrs ago.

What you say does make sense and I do remember when the ET Turbo Nissan pulsar came out , pulling the ECU power fuse is just what we used to do as there was no pedal sequence way back then.

When my D40 was about 15k old it used to get unreal fuel figures like under 8's , then it went in for some warranty work and its never been the same, they said they never touched anything but now you got me thinking what if the pedal sequence was done incorrectly in the first place meaning that the ECU kept this fault if you like since then.

I'm going to take her for a drive today get her warn and remove the leads earth them out to discharge everything and see what the fuel figures will be like after that.

Come to think of it , Who hear remembers having the air bag recall ??? I wonder if some firmware was added when they hooked it up to their laptop and changed other things at the same time , it was around the 15k hhhhmmm I wonder

So once the earthing discharge has been done everything will (should) reboot to the standard factory presets - CORRECT ? and the air bag firmware that was added at a later stage should resort back to its former state right ?

Tell me this you say it makes a difference at what temp you change the air filter , how do you come to this assumption and the thought of the air bags discharging did cross my mind as well has any Diesel owner made this earth discharge on there vehicle ?

Marty