Limp mode

[Carlh]

Right peeps. I have a 2009 is220d. And for some reason keeps going into limp mode. I can drive 100 mile to work and will be fine. Then when I come back go into limp mode twice. Please help

[ColinBarber]

18 minutes ago, Carlh said:

Then when I come back go into limp mode twice

Have you plugged in a code reader to obtain the fault code(s)?

[Carlh]

Not yet was just asking around first to see if anyone has any ideas 

[H3XME]

6 hours ago, Carlh said:

Not yet was just asking around first to see if anyone has any ideas 

Without a read out there could be 1001 guesses. Won't be helpful

[Carlh]

Put a code reader on there. And no code is showing

[Carlh]

3 times went into limp mode within 60 miles. Then went like a rocket

[Linas.P]

Is it actually Limp mode? By that you should have Engine + VSC Lights... I don't remember if IS220d also says "LIMP" on the display, but certainly you must have engine lights.

Or is it just down on power? Because the later could be caused by blocked diesel filter, or blocked air filter or some other issues which may not give fault codes. The actual Limp mode will give fault.

[Carlh]

Well that is more like it loss of power. But I call limp mode as won’t go above 2000 revs

[Linas.P]

Is it more like hard limit i.e. car revs freely up-up 2000RPM and then just sits there or is it more like car seems to be unable to reach more than 2000RPM?

I mean it could be something like dead throttle body, but that should give fault code. Or it could still be something related with fuel filter or even fuel pump pick-up... it sucks something up and gets blocked.

[H3XME]

13 hours ago, Linas.P said:

could be caused by blocked diesel filter

Do these not have like "DPF Cleaning" dash light of some sort? Some diesels are good and they tell you when it's cleaning the DPF, some diesels even let you clean it manually like a Land Cruiser. 

[Shahpor]

When was the last time the EGR valve was cleaned?

If not in a while, then a relatively easy first step as it will most likely need cleaning anyway.

[Shahpor]

4 hours ago, H3XME said:

Do these not have like "DPF Cleaning" dash light of some sort? Some diesels are good and they tell you when it's cleaning the DPF, some diesels even let you clean it manually like a Land Cruiser. 

Nope, the only way to manually start a cleaning cycle is via TechStream.

Usually you can tell when a DPF cleaning is running as lots of smoke comes out the back!

[Linas.P]

4 hours ago, Shahpor said:

Nope, the only way to manually start a cleaning cycle is via TechStream.

Usually you can tell when a DPF cleaning is running as lots of smoke comes out the back!

.... diesels!

Wouldn't blocked EGR trigger some light, like DPF efficiency or something along those lines, especially if car can't even get over 2000RPM. Also wouldn't EGR be just increasingly more and more sluggish, rather than on-off "limp"?  

8 hours ago, H3XME said:

Do these not have like "DPF Cleaning" dash light of some sort? Some diesels are good and they tell you when it's cleaning the DPF, some diesels even let you clean it manually like a Land Cruiser. 

I meant actual fuel (diesel) filter, not blocked DPF. If DPF would be blocked to this extent where car does not run above 2000RPM, then I would expect it would trigger the fault code for "DPR performance below threshold".

[Shahpor]

3 hours ago, Linas.P said:

Wouldn't blocked EGR trigger some light, like DPF efficiency or something along those lines, especially if car can't even get over 2000RPM. Also wouldn't EGR be just increasingly more and more sluggish, rather than on-off "limp"?  

Mostly likely, but if there are no codes showing, then who knows?

At this point, you would need TechStream to see what is going on and run some diagnostics.

[ColinBarber]

If it went into limp mode then the CEL would come on and there would be error codes stored that any quality code reader could be able to pick up.