View Full Version : D40 Engine Problem??? Limp mode???

04-08-2010, 10:30 AM
Wondering if anyone can help me out? Was driving in Sydney today when my Nav lost power and would not rev. I pulled over believing it had placed itself into limp mode but the check engine light was not on. I tried to rev the engine but would not rev. I turned the ignition of and let sit for 5 or 10 seconds and then restarted. After restart it was as good as gold and then drove back up the F3 to newcastle with no further problems. Very strange and worried it may happen again.

Any ideas?

04-08-2010, 10:36 AM
Might have overboosted.


04-08-2010, 10:37 AM
Yep, you went into limp mode, mine didn't come up with the check light either.

04-08-2010, 10:49 AM
Do i panick and take it straight to Nissan or just wait and see what happens ?

04-08-2010, 10:52 AM
If it was an overboost Nissan may not see anything and just tell you there's nothing wrong. I'd be seriously tempted to just continue driving it and see if it does it again, and be aware of what you'd been doing when it happened - heavy acceleration, hill climbing etc.

04-08-2010, 10:53 AM
I'd wait, mine hasn't given any more problems.
I was revving mine pretty hard trying to extract myself out of a bog hole.

04-08-2010, 11:12 AM
Just normal road driving for me at the time. No hard revving or accelerating. I did do the ECU reset or learning mode procedure the other week with the accellerator procedure. Have been towing a scissor lift around quite regular and this is probably the first tank without towing.....wonder if the ECU has learnt incorretly due to towing heavy loads?

04-08-2010, 11:21 AM
You could try the power-off reset method and try again. You might be onto something.

06-08-2010, 11:25 AM
It happend again today a total of 3 times and believe it or not 2 of them were in the same section of road - merging onto motorway from 60 km to klm and when i put the foot down on all occasions. Removed negative lead this afternoon to reset ECU so will be interesting to see if comes back again....hope not!

06-08-2010, 11:29 AM
It happend again today a total of 3 times and believe it or not 2 of them were in the same section of road - merging onto motorway from 60 km to klm and when i put the foot down on all occasions. Removed negative lead this afternoon to reset ECU so will be interesting to see if comes back again....hope not!

If it happens again don't do the reset, take it to Nissan and tell them to check the fault code. Sounds like you've got a problem.

06-08-2010, 11:34 AM
If it doesn't happen again, I think we need to modify the "ECU Reset Instructions" to be:

1) Unload your vehicle and unhitch any trailer
2) Note down the km on your tripmeters if you use these for economy calculations
3) Disconnect the negative lead from your battery
4) Turn your vehicle ON for 10 seconds then turn it off
5) Reconnect the negative lead to your battery

Points 1 and 6 are new.

Let's see how Beergutz goes.

06-08-2010, 11:35 AM
Yeah i definatly will, just wanted to make sure that doing the learning mode reset didnt have anything to do with it first.

07-08-2010, 12:16 AM
Is it a auto or man
some things it might be are
if its a auto they have a tp sensor in the auto which makes a fualt simlar to this if its that the tp sensor is part of the valve body from memory about 1500 bucks
if its a auto i would sugest cleaning the earth located on the right hand guard kinda near the power steer resawar if you look down you will see it bolted to the guard in between all the wires try this and see if it works.

if its a manual it will the frp sensor (fuel rail pressure sensor ) also try cleaning the earth located on your iner guard (rhs) on the inside beside your ecu its a bit of arse to get at this is the main earth that operates everything on the right hand side of your car (al sensors and also your throttel.

Just a note the other main earths are located under the air box if you wish to give them a clean when you clean the earths spread the locking tabs and twist the earth so you can see behind the back of it you might find a lot of green behind there good luck

07-08-2010, 09:35 AM
Thanks for the heads up Ralphn, I have done the ECU reset and so far so good. ITs an 08 stx auto. Ill check the earths tomorrow. Gonna give my cousin a call on Monday as he is the head service mechanic at Kloster Nissan here in Newcastle and discuss it with him. Will keep you posted.

17-08-2010, 02:09 PM
Alright fella's its been a couple of weeks since i had the limp mode issues. Since i have done the ECU full reset by removing the negative lead off the battery i havent experienced this problem at all.....touch wood. My fuel economy has improved and i get another 60-70ks a tank which is better than a kick in the nuts.

I spoke to my relo who is a nissan service mechanic and explained what i had done, when i thought i had reset the ECU by depressing the accelerator 5 times after turning ignition on ect ect. He told me this more than likely placed the ECU into learning mode where it monitord driving habits and adjusts paramaters to suit. He explained that the ECU uses "fuzzy logic" which from my experience in the electrical trade is when the electronics basically learns from its own experiences and adjusts itself for the next time an event happens. I had placed my nav into learning mode. Becuase i had towed my scissor lift after doing this it basically taught the computer that it needed plenty of juice andall hands on deck from a standing start to help pull the 2.5t up to speed. When driving without load the computer believed it still had load on the car and would have responded by using the paramaters it had learnt with load......this was the mosted probable cause for the limp mode.

So a warning to all......If you carry out the learning mode process by using the accelerator method IT DOES NOT RESET ECU be carfull that you do not have to tow any loads as the ECU will get confused and more than likely cause a limp mode event. Follow OldTony's method by removing the negative terminal lead off the battery. This method discharges all power from the ECU and resets it back to default, but beware that it will wipe all fault codes stored. I learnt the hard way but looks like i got out of it cheap.

Hope this of help.

06-09-2010, 09:43 AM
great thread mate, i have been having similar problems but i think mine is chip related. thanks for the info

06-09-2010, 01:28 PM
No problems dwayne. Thought it should be put out there. Been over a month now since first issue poked its ugly head out. Had no further problems since full reset. I say forget about using the accelerator method and placing the car into learning mode, just do full reset as per Old.Tony's procedure and ensure no heavy towing or hard driving first up as it will input incorrect parameters into ECU.