Limp mode

Carlh · March 11

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 · March 11

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 · March 12

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

H3XME · March 12

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 · March 12

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

Carlh · March 12

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

Linas.P · March 12

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 · March 12

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

Linas.P · March 12

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 · March 13

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 · March 13

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 · March 13

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 · March 13

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 · March 13

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.