Help with limp mode!!! Very Confused !! Mitsubushi Canter!!
Discussion
Hi all, I'm seeking some advice on a problem I am having with an old Mitsubishi Canter truck! I know its not a grand sports car or even a car but I am running out of options so I'm hoping there are some old school mechanically minded folk on here who may be able to help.
So brief run down, the truck would occasionally go into limp mode for no apparent reason (not when under load, or particularly hot etc) just when ever it felt like it, pull over switch off and restart and all would be good again. It went to a garage no faults found, then it started to be more often, again no fault can be found, now it does it all the time and goes into limp mode after 6 seconds of idleing (this is a new symptom always before done it while driving), still garage can find no fault and no fault codes given.
Next steps I thought thinking logically I replaced the air filter, fuel filter, oil and still problem exactly the same, looked at all vacuum pipes and all appear to be fine, so today I went out and blanked off the EGR valve and the limp mode now takes longer to kick in (about 14 seconds), so obviously this has made a change somewhere to it?? and then I found out that very strangely that if after starting the truck before limp mode kicks in if I rev it above 2k rpm and keep it there or higher limp mode doesn't happen, but when revs drop back down a few seconds later it kicks in, and then the truck wont go above 2k and more than 50mph (either empty or fully loaded)!!!!
So does anyone have any ideas on what I could try next, or what may be causing it?? it is an old truck but its good at what it does when it works, so really want to keep it, plus I don't have a load of money to throw at buying a new one. It is old and simple, its a 2002 3.0 turbo diesel, very few electrics (crank sensor, intercooler sensor, MAP sensor, Oil Temp, and water temp and that's about it electric wise I think) the only other things to point out is its slow to start with until it gets warmed up but has always been like this even before the limp mode first happened as far as I can remember, and the exhaust brake which I never use doesn't work, it used to but not anymore (doesn't even switch on at the dash with the lever). Just mentioning these two incase it might be linked.
I know its a long shot to find a Mercedes commercial mechanic on here who works on Mitsubishi Canters for a job (sold and serviced by Mercedes UK), but hoping to find someone with some good logically engine knowledge who maybe able to help!!
Cheers Steve
So brief run down, the truck would occasionally go into limp mode for no apparent reason (not when under load, or particularly hot etc) just when ever it felt like it, pull over switch off and restart and all would be good again. It went to a garage no faults found, then it started to be more often, again no fault can be found, now it does it all the time and goes into limp mode after 6 seconds of idleing (this is a new symptom always before done it while driving), still garage can find no fault and no fault codes given.
Next steps I thought thinking logically I replaced the air filter, fuel filter, oil and still problem exactly the same, looked at all vacuum pipes and all appear to be fine, so today I went out and blanked off the EGR valve and the limp mode now takes longer to kick in (about 14 seconds), so obviously this has made a change somewhere to it?? and then I found out that very strangely that if after starting the truck before limp mode kicks in if I rev it above 2k rpm and keep it there or higher limp mode doesn't happen, but when revs drop back down a few seconds later it kicks in, and then the truck wont go above 2k and more than 50mph (either empty or fully loaded)!!!!
So does anyone have any ideas on what I could try next, or what may be causing it?? it is an old truck but its good at what it does when it works, so really want to keep it, plus I don't have a load of money to throw at buying a new one. It is old and simple, its a 2002 3.0 turbo diesel, very few electrics (crank sensor, intercooler sensor, MAP sensor, Oil Temp, and water temp and that's about it electric wise I think) the only other things to point out is its slow to start with until it gets warmed up but has always been like this even before the limp mode first happened as far as I can remember, and the exhaust brake which I never use doesn't work, it used to but not anymore (doesn't even switch on at the dash with the lever). Just mentioning these two incase it might be linked.
I know its a long shot to find a Mercedes commercial mechanic on here who works on Mitsubishi Canters for a job (sold and serviced by Mercedes UK), but hoping to find someone with some good logically engine knowledge who maybe able to help!!
Cheers Steve
stevieturbo said:
If it is going into limp mode with the CEL light on, there WILL be codes.
Anyone who says there are no codes either is not using the equipment correctly or it is the wrong equipment.
I don't know about that, or exactly what they were using, one garage showed me a snap on tool which couldn't read/find a fault, another garage a blue coloured machine, an AA man had no luck with his, and another garage showed me doing a 'blink' test on dash lights, and management light flashed at regular intervals meaning no fault code present, where as if it apparently done for example 1 long flash followed by 3 short flashes it would be code 13, but this just kept giving solid flashes meaning no fault?Anyone who says there are no codes either is not using the equipment correctly or it is the wrong equipment.
are these commercial garages your going to or just regular car garages in there just general garages then their diagnostic scanners are unlikely to have software for commercial vehicles. My top of the range Snap On scanner doesnt do commercial vehicles without buying and loading the software which is basically the price of the tool, the AA patrols certainly dont carry scanners with commercial software.
SteveoJ said:
I don't know about that, or exactly what they were using, one garage showed me a snap on tool which couldn't read/find a fault, another garage a blue coloured machine, an AA man had no luck with his, and another garage showed me doing a 'blink' test on dash lights, and management light flashed at regular intervals meaning no fault code present, where as if it apparently done for example 1 long flash followed by 3 short flashes it would be code 13, but this just kept giving solid flashes meaning no fault?
If the CEL is on and it is in limp mode, there will be codes. Fact, end of story.So is the light on ?
Some sort of power reduction with no light on, may not be a limp mode.
And it almost sounds like those trying are failing to communicate with the car, rather than having no codes. The two are not the same.
There could be various reasons why that is the case.
So drive car, do whatever is needed to cause this alleged problem to occur, then immediately check for codes. Do not switch the car off prior to doing this.
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