limp mode

[neil1971]

Hi, i have a mercedes a class 180cdi 2lte diesil and has some faults on it , main concern is goes into limp mode as soon as i pull away, a mechanic has had it on computer showing faults see photos, now he has no idea what is wrong and why it foes into limp mode he said there is some contradictions in fault finding and said it seems the abs/esp its throwing it in limp mode but can not say any ideas. As it comes up run flat fault and abs,esp fauly, and engine light is on also. car drives spot on in limp mode no misfires and pulls ok no smok etc just wont go over 2800rpm. Any advice and help on this and cost would be appreciated.

 

[Smart320]

ABS wheel sensor at a guess especially as it only shows up once you start rolling , it will throw up lots of warnings ,

 

[jc651]

Check the boost hoses for splits is a start as that would explain the low charge pressure and if a pipe is split that would explain the EGR fault. Your not far from me so if your stuck let me know.

 

[design guru]

Make sure your battery is ok before you start replacing parts. My S Class went into limp mode and everything pointed towards the gearbox but it turned out to be a dying battery.

 

[neil1971]

ABS wheel sensor at a guess especially as it only shows up once you start rolling , it will throw up lots of warnings ,

would this put it into limp mode didnt think this would with not been the engine

 

[neil1971]

Check the boost hoses for splits is a start as that would explain the low charge pressure and if a pipe is split that would explain the EGR fault. Your not far from me so if your stuck let me know.

will do its in the garage at the minute in shiney row bloke stumped at the minute ill mention this to him

 

[neil1971]

Make sure your battery is ok before you start replacing parts. My S Class went into limp mode and everything pointed towards the gearbox but it turned out to be a dying battery.

would batterty not show on diagnostics

 

[neil1971]

Check the boost hoses for splits is a start as that would explain the low charge pressure and if a pipe is split that would explain the EGR fault. Your not far from me so if your stuck let me know.

what do you think on it been a abs sensor as someone mentioned ?

 

[W1ghty]

what do you think on it been a abs sensor as someone mentioned ?

MB Specialist with Star diagnostics buddy , there is a lot of guessing going on .

 

[neil1971]

MB Specialist with Star diagnostics buddy , there is a lot of guessing going on .

is this expesive

 

[neil1971]

just seems strange how i can start it let it sit there rev it etc and no warnings as soon as drive off the car warning lights come on abs/esp , run flat, engine light and in limp mode everytime switch it off then back on same no lights drive off after hits the high revs for a minute driving then same limp mode.

 

[zipdip]

Well your last post points to a a ABS sensor,you say you can rev the car to more than 2800rpm while stationary and you get zero faults,drive off and you get loads of faults and are in limp mode,best you get if on star,but if you must that sensor comes into play the minute you start to move,but a indy with a star will cost about £60,and if it is a ABS sensor they are not that expensive and do not take too long to change.

 

[W1ghty]

is this expesive

As @zipdip said above , about £60 .

 

[neil1971]

im getting the abs sensor , the wheel bearing and the egr valve replaced while he has the engine stripped £300 incuding labour and hopefully this sorts the issues out

 

[W1ghty]

im getting the abs sensor , the wheel bearing and the egr valve replaced while he has the engine stripped £300 incuding labour and hopefully this sorts the issues out

Good luck buddy , let us know how you get on

 

[jc651]

If you get stuck I am back to work on Monday ( tyre spot ....houghton ) and I'm sure I can get you sorted out. Just ask for John

 

[neil1971]

Good luck buddy , let us know how you get on

will do hope it sorted

 

[neil1971]

If you get stuck I am back to work on Monday ( tyre spot ....houghton ) and I'm sure I can get you sorted out. Just ask for John

ok mate appreciate that thank you mate

 

[Jase46]

Be interested in what they find as my e320 Cdi has similar issue. Low boost pressure. The mb specialist I went to said boost sensor, so I changed it made no difference, I cleaned out the egr even though it wasn’t that bad just sooted up. My Audis was like tar in comparison. Made no difference. So I changed the o2 sensor as the diagnostic m/c had that defective, again made no difference. I did find the left side inrercooler pipe split as it was spraying oil on the radiator. Again made no difference. I checked the right side pipe and is ok but did feel soft. (Could it be collapsing when boosting)? Changed air and fuel filters just for good measure no change. If anyone has any input I’d really appreciate it. And sorry for the highjack of this post.

 

[neil1971]

Well update the abs sensor has been replaced and bearing and also a new egr fitted total cost £300
The abs/esp lights now have cleared and that is fine, he took car on a run up to 75mph came back I take care away about 20 minutes after getting car the car goes in limp mode again ans engine light is on. Turn ignition off limp mode goes off but engine light still on once driving limp mode kicks in.
mechanic also checked all vacuum pipes etc when did the jobs and suggests may be something that controls the egr valve a sensor or summit any ideas