Limp Mode

[scrubrat]

This might be a dumb question,but can someone please explain to me what ' Limp Mode 'is.

Cheers

Gary

[NissanGQ4.2]

nothing is a dump question Gary,

I'm not 100% on exactly what it is, I believe if you have an ECU error it will put you into limp mode and allow you to "LIMP" home so 2 speak, I'm sure someone will be able 2 assist you shortly and give you a better answer.

[Yendor]

Toddrhind is correct, the ECU performs test on it's self, input sensors and some output circuits.

Now if it detects a fault within the engine's management system that will prevent it from calculating and running the engine within it's safe working parameters.

The ECU can run the engine in LIMP mode which is a base factory setting for things like fuel delivery (both amount and timing) spark timing (petrol engines).

It is designed so you can basically limp it home or to a mechanic for repairs.

Now depending on what vehicle we are talking about (as each vehicle manufacturer is different) when it goes into LIMP mode the ECU may also do other things such as turn engine cooling fans on or make auto's take off in 3rd gear.

ECU's also have other fail safe features built in such as, if your engine temperature goes above the ECU's preset safe working parameter it will turn your air conditioning off to try and bring down the engine temperature (this wont necessarily put it into limp mode).

I hope this answers your question.

Regards Rodney

[NissanGQ4.2]

only if i said it like that, I knew what i was talking about *L* Thanks Rodney

[scrubrat]

Thanks for the explanation guys,my knowledge base is slowly starting to expand.

Cheers
Gary

[katwoman]

This might be a dumb question,but can someone please explain to me what ' Limp Mode 'is.

Cheers

Gary

Can I answer that one ??? Too much alcohol.. Hahahaha. Sorry, back in my box.

[nowoolies]

Can I answer that one ??? Too much alcohol.. Hahahaha. Sorry, back in my box.

oi oi oi hahahahahaha

[NissanGQ4.2]

Can I answer that one ??? Too much alcohol.. Hahahaha. Sorry, back in my box.

good 2 know i must never drink 2 much....hahahahahahahahaha

[rowlund]

I actually experienced this with my nissan sedan. the limp mode as had been explained to me was something like the vehicle going in self preservation mode where it sets limits on itself after the ECU detects something seriously wrong. When my sedan went and displayed the check engine light and the light didn't go off, the car had gone on limp mode and among other things limited my shifting ti higher gears and set my speed to 50kph max. THis allowed the vehicle to "limp" home so to speak, but sets limits to avoid more serious damage to itself.

[Greengu98]

my tacho sender has broken had mechanic tell me would go to limp mode but not yet! yay haha, still need to the sender.. hmmm