E320 CDI Power Loss and Limp Home Mode
"I have a 2005 CDI just 1 year old, 21K miles on it. I've had similar issues. After about 6 months the car would accasionally cough and stall, or cough then run.......coasting off a highway ramp, asked for power, got none. Acceleration was limited and engine noise was distinctly louder...... MB found that stopping and restarting it restored power. They told me this was the computer putting the car in the Limp Home Mode. This code occurs when the computer thinks that continued use might damage the engine, so it restricts output to half throttle and transmission to lower gears.
AFTER THE EGR VALVE WAS REPLACED, CAR IS BACK TO DELIGHTFUL SELF....."
It looks like they are having some EGR problems. I am putting a note in my Operating Manual regarding the loss of power problem.
AFTER THE EGR VALVE WAS REPLACED, CAR IS BACK TO DELIGHTFUL SELF....."
It looks like they are having some EGR problems. I am putting a note in my Operating Manual regarding the loss of power problem.
seems to be a common problem, this happened to me and it was the same problem
Jay
Jay
The valve should only open at part throttle. At idle or with a closed throttle, the valve should close to prevent exhaust gasses from getting to the intake. If the valve fails to close you can have a rough idle or similar problems. With modern engines, electronics and sensors are used rather than the old vacuum method so there could be something else besides the EGR Valve at fault.
EGR is designed for one purpose, to reduce emissions. Otherwise, it woudn't be there.
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With the $$ I save I will replace the flexible disc on the driveshaft, then onto the upgrading the calipers and rotors......
Anybody know where I can get a decent tune for low $$ I'd like to go with GDE but I have kids to put through college.
Took it into my dealer who confirmed there are no problems only the electric motor that operates the limp mode is faulty.
Quote for parts and labour $3K.
Is there any way to override limp mode via the computer or eliminate limp mode mechanically?
Car is like new, 150K km full dealer service history from new,
Thanks
Last edited by Al Spaeth; Jun 18, 2019 at 05:09 AM.
Took it into my dealer who confirmed there are no problems only the electric motor that operates the limp mode is faulty.
Quote for parts and labour $3K.
Is there any way to override limp mode via the computer or eliminate limp mode mechanically?
Car is like new, 150K km full dealer service history from new,
Thanks
- Faulty mass air sensor (MAS)
- Electronic throttle actuator problems
- Broke, cracked, loose wiring harnesses
- Faulty brake light sensor
- Corroded computer module contacts (i.e.: transmission control unit, transmission shift module)
- Problems with transmission valve body and/or conductor plate
Ask dealer to clarify exactly what it is they are suggesting to replace.
Last edited by Doug Ferguson; Apr 28, 2020 at 05:08 PM. Reason: typo
"I have a 2005 CDI just 1 year old, 21K miles on it. I've had similar issues. After about 6 months the car would accasionally cough and stall, or cough then run.......coasting off a highway ramp, asked for power, got none. Acceleration was limited and engine noise was distinctly louder...... MB found that stopping and restarting it restored power. They told me this was the computer putting the car in the Limp Home Mode. This code occurs when the computer thinks that continued use might damage the engine, so it restricts output to half throttle and transmission to lower gears.
AFTER THE EGR VALVE WAS REPLACED, CAR IS BACK TO DELIGHTFUL SELF....."
It looks like they are having some EGR problems. I am putting a note in my Operating Manual regarding the loss of power problem.
My 2005 CDI with 200k miles has the coughing problem and occsional loss of power. Check engine light came on and it threw the EGR value issue. After changing the EGR valve, the check engine light went away but the problem of coughing hesitation and occasiional loss power still exists although diminished. I looked at this blog and someone had posted switching to lower gear and blasting the carbon deposits in entry ramps to highways and stop driving like an old lady. When I switch to the lower gear, the power is back on. Any suggestions from the group is much appreciated. There are not too many trained mechanics that I know of who can deal with Mercedez Diesel who are reasonable in Sandiego area. Thanks in advance for your input.



