Limp Mode in Xterra

[Thomas Varghese]

Yesterday during my drive with @Luca Palanca Falsini @Shaaz Sha my Xterra went into limp mode towards the end of the drive. The car wouldn't rev beyond 1000 rpm. Morning I got back my car after an ECM programming and everything works fine. The mechanic told me this happened due to constant acceleration and deacceleration of the car for a long time. I thought the explanation was bizarre and checked with @Frederic and he concurred on my Mechanic's observation. I still didn't believe both and consulted Nissan and they confirmed its a known fact for Nissan throttle bodies. Historically all Thomas's are doubting Thomas's. Well all the Xterra owners out there in the club - @Chaitanya D, @Foxtrot Oscar, @M.Seidam, @Tbone, @Rizwanm2, @Shaaz Sha, @Chinthaka Ruwan, @Brendan White , @Xavier Treasurer, @Janarthan, @Mukundan Nair beware this can incapacitate your X in the middle of a drive. Be careful. Kindly tag other Xterra owners who are unknown to me. 

As per Nissan once the throttle body motor cools down the car should rev up again but it didn't happen yesterday and @Russ had to tug me out. My mechanic said once the check engine light comes on it cannot be back to operational status until the code is cleared and throttle body is programmed. 

Side note:- On the brighter side my X seems to give a better gas mileage after the throttle body programming. 

Edited October 30, 2021 by Thomas Varghese

[Xavier Treasurer]

Hi Thomas, 

Thanks for sharing. I had a similar issue a few weeks back and got myself an OBD 2 reader that’s always with me to avoid getting stranded.

[Thomas Varghese]

7 minutes ago, Xavier Treasurer said:

Hi Thomas, 

Thanks for sharing. I had a similar issue a few weeks back and got myself an OBD 2 reader that’s always with me to avoid getting stranded.

A good OBD2 programming computer should cost upwards of 7000 AED. Normal ones can tell you the problem but is not much help to programme the ECM

Edited October 30, 2021 by Thomas Varghese

[Xavier Treasurer]

Sure but all you need to is clear the fault codes so the car can be driven to safety/ your nearest garage. You do not necessarily have to take the garage to the desert. 

[Thomas Varghese]

6 minutes ago, Xavier Treasurer said:

Sure but all you need to is clear the fault codes so the car can be driven to safety/ your nearest garage. You do not necessarily have to take the garage to the desert. 

By the way even after clearing the code the car didn't rev up until the throttle body relearning process was done. I'm not an expert on OBD2 readers. 

 

[Cha]

Thanks @Thomas Varghese for this post, I would be going home in a recovery truck yesterday if I didnt remember to read this post and do the relearning.

the throttle body control relearning can be done manually, I did last night and the limp mode was gone immediately, also this procedure corrects the idle RPM if you removed or cleaned throttle control body/MAF. Here is the video.

 

I still doubt the issue is throttle control body motor overheat, as my limp mode activated not during the drive, but after inflation and hitting the road. Ambient temperature was 11C, and the bonnet was open, the motor should have enough time to cool down. But constant acceleration and deacceleration yes, it was a really fun IM Yalla drive with Angela.

I suppose there are 2 types of limp mode, a major one and a minor one. I have had both:

• The minor one should be gone by turning off and on the engine.
• If the limp mode presists it's the major one, you will have to let the throttle control body rest, and do the relearning.

The minor one happened to me onroad few times, because I was running behind clock and I used pedal commander, I definitely did constant acceleration and deacceleration, and pedal commander enlarged the signal to throttle control body.

 

@Foxtrot Oscar I think you had the minor one yesterday, if thats the case you probably wouldnt get any error code from OBD. BTW Zed's OBD reader didnt work on my Nissan as well =-=

Edited January 24, 2022 by Zixuan Huang - Charlie

[Foxtrot Oscar]

11 minutes ago, Zixuan Huang - Charlie said:

Thanks @Thomas Varghese for this post, I would be going home in a recovery truck yesterday if I didnt remember to read this post and do the relearning.

the throttle body control relearning can be done manually, I did last night and the limp mode was gone immediately, also this procedure corrects the idle RPM if you removed or cleaned throttle control body/MAF. Here is the video.

 

I still doubt the issue is throttle control body motor overheat, as my limp mode activated not during the drive, but after inflation and hitting the road. Ambient temperature was 11C, and the bonnet was open, the motor should have enough time to cool down. But constant acceleration and deacceleration yes, it was a really fun IM Yalla drive with Angela.

I suppose there are 2 types of limp mode, a major one and a minor one. I have had both:

• The minor one should be gone by turning off and on the engine.
• If the limp mode presists it's the major one, you will have to let the throttle control body rest, and do the relearning.

The minor one happened to me onroad few times, because I was running behind clock and I used pedal commander, I definitely did constant acceleration and deacceleration, and pedal commander enlarged the signal to throttle control body.

 

@Foxtrot Oscar I think you had the minor one yesterday, if thats the case you probably wouldnt get any error code from OBD. BTW Zed's OBD reader didnt work on my Nissan as well =-=

Thank you so much for detailing this . I’m glad you got home safe !

[Thomas Varghese]

5 minutes ago, Zixuan Huang - Charlie said:

Thanks @Thomas Varghese for this post, I would be going home in a recovery truck yesterday if I didnt remember to read this post and do the relearning.

the throttle body control relearning can be done manually, I did last night and the limp mode was gone immediately, also this procedure corrects the idle RPM if you removed or cleaned throttle control body/MAF. Here is the video.

 

I still doubt the issue is throttle control body motor overheat, as my limp mode activated not during the drive, but after inflation and hitting the road. Ambient temperature was 11C, and the bonnet was open, the motor should have enough time to cool down. But constant acceleration and deacceleration yes, it was a really fun IM Yalla drive with Angela.

I suppose there are 2 types of limp mode, a major one and a minor one. I have had both:

• The minor one should be gone by turning off and on the engine.
• If the limp mode presists it's the major one, you will have to let the throttle control body rest, and do the relearning.

The minor one happened to me onroad few times, because I was running behind clock and I used pedal commander, I definitely did constant acceleration and deacceleration, and pedal commander enlarged the signal to throttle control body.

 

@Foxtrot Oscar I think you had the minor one yesterday, if thats the case you probably wouldnt get any error code from OBD. BTW Zed's OBD reader didnt work on my Nissan as well =-=

Other reasons for the limp mode is sand intrusion into the MAF sensor past the air filter, wiring harness being loose maybe at the MAF sensor or the throttle control actuator valve. Even the loose wiring harness on the O2 sensor produces a check engine light and limp mode. In fact a bad crank position sensor also can give a limp mode. 

[Cha]

15 minutes ago, Thomas Varghese said:

Other reasons for the limp mode is sand intrusion into the MAF sensor past the air filter, wiring harness being loose maybe at the MAF sensor or the throttle control actuator valve. Even the loose wiring harness on the O2 sensor produces a check engine light and limp mode. In fact a bad crank position sensor also can give a limp mode. 

Then probably some sand in MAF, I always blow the residue sand away from the air filter container after each drive, very likely some got into MAF and caused the limp mode. Will get a car use vaccum machine to do the job then, thanks again Thomas, always learning things from you! 

 @Chinthaka Ruwan Be aware of this

[Thomas Varghese]

4 minutes ago, Zixuan Huang - Charlie said:

Then probably some sand in MAF, I always blow the residue sand away from the air filter container after each drive, very likely some got into MAF and caused the limp mode. Will get a car use vaccum machine to do the job then, thanks again Thomas, always learning things from you! 

 @Chinthaka Ruwan Be aware of this

@Zixuan Huang - Charlie I do the same after every drive. I clean the air filter and the filter box after every drive. Remove the lid of the air filter box by unscrewing the rubber hose which connects it to the rest of the inlet manifold plenum. Its very simple - use a flat head screw driver to unscrew the clamp. Remove the MAF sensor also with the cross screw driver and spray some sensor cleaner to it. Cover the rubber hose with a good cloth and then blow the sand from the filter box. Otherwise all the dust will reach to your throttle body. Regular practice will ensure you get best performance in gas mileage and engine response. Putting back the plastic air filter box in the correct way in crucial for no leakage into the throttle body or the MAF sensor. There are 3 sliding locks on the back of the filter box and make sure the tongue of the top lid slides into the socket of the bottom lid properly before you snap on the clips on the right side of the box to shut the box. This is very crucial as if not done properly will damage your engine for ever.