Labored Shifting, Limited Power Output
Thread Starter
Junior Member
Joined: Sep 2016
Posts: 27
Likes: 2
2004 MB E320 Wagon
Labored Shifting, Limited Power Output
I am attempting to arm myself with options and opinions prior to visiting my dealer regarding this 7G transmission issue. Thank you for any contribution.
This truck has and does run beautifully, and this issue only presented itself last week. Basically, it runs out of power and has delayed dramatic upshifts. Here are the finer points:
2014 ML350 Bluetec 4Matic
VIN #4JGDA2EB9EA269079
Trans #72290304971195
119K miles
Symptoms, from a stop:
20K miles since last transmission fluid service
Transmission, engine, and power delivery appear strong and healthy when issue is absent.
No codes indicating conductor plate/speed sensors; dealer suspects valve body, based on description (with $2500 estimate)
Codes, most stored:
B21 0113
P25567B
C220500
121500
184000
B1 DD01 5
U01 4786
U01 2986
B1 FBD04
U01 3287
Does this sound fairly cut and dry to anyone? Would there normally be a software intervention prior to physical repair? Any recommendations in diagnosing, hypothesis testing, or likely diagnoses are very much appreciated. –Michael
This truck has and does run beautifully, and this issue only presented itself last week. Basically, it runs out of power and has delayed dramatic upshifts. Here are the finer points:
2014 ML350 Bluetec 4Matic
VIN #4JGDA2EB9EA269079
Trans #72290304971195
119K miles
Symptoms, from a stop:
- Accelerates normally (from what I can briefly sense) to 2500 rpm, then maintains the same velocity/power before finally upshifting several seconds later (@3000 rpm)
- Repeats this behavior for each subsequent gear
- Upshift is delayed, with a soft “jerky” engagement of subsequent gear
- Modulating the throttle (from light to full acceleration positions) has no strong effect on engine speed/power output
- Slowly accelerates to normal highway speeds (approx 10-12 sec from stop), with no increase in available power at any road speed
- Fails to respond to paddle shifter input
- Activates CEL only half of the time
- Issue disappears or “resets” after powering key off
- Frequency of issue increasing from occasional to frequent over a period of one week of steady driving (currently parked)
- No transmission related codes seem to appear on my Autel code reader (see below)
- Issue does not fluctuate with engine temp, or fuel level
- Initiates from either start or mid-drive
- Issue did begin immediately after adding a string dose (2X) of PS Diesel Kleen; however, no such issue on a dozen prior additive additions (coincidence?)
20K miles since last transmission fluid service
Transmission, engine, and power delivery appear strong and healthy when issue is absent.
No codes indicating conductor plate/speed sensors; dealer suspects valve body, based on description (with $2500 estimate)
Codes, most stored:
B21 0113
P25567B
C220500
121500
184000
B1 DD01 5
U01 4786
U01 2986
B1 FBD04
U01 3287
Does this sound fairly cut and dry to anyone? Would there normally be a software intervention prior to physical repair? Any recommendations in diagnosing, hypothesis testing, or likely diagnoses are very much appreciated. –Michael
Thread Starter
Junior Member
Joined: Sep 2016
Posts: 27
Likes: 2
2004 MB E320 Wagon
How might I go about checking the mentioned variables? Would the exhaust restriction still “reset” upon turning off the engine?
Senior Member
Joined: Apr 2012
Posts: 356
Likes: 66
2012 ML350 Bluetec, 2015 GL350 Bluetec
I would first get a star or Xentry system hooked up and look for trouble codes, especially in the engine and transmission modules see if there's any info. This will give you idea whether it's an engine issue or transmission issue then you can start from there. If it's engine issue, see what the code tells you and perform appropriate work. The OM642 engine is known to be problematic if not maintained properly so that's not surprising. If it's a transmission issue, I would first check the fluid level and condition. If level is correct, drop the pan and cut open the filter see if you can find any metal particles in the pan and filter. If there is then the transmission is shot. If not, depending on the condition of the fluid, you can consider dropping the valve body and clean it thoroughly. After putting everything back you can perform a relearn of the transmission. This should solve the issue.
Thread Starter
Junior Member
Joined: Sep 2016
Posts: 27
Likes: 2
2004 MB E320 Wagon
If it's engine issue, see what the code tells you and perform appropriate work. The OM642 engine is known to be problematic if not maintained properly so that's not surprising. If it's a transmission issue, I would first check the fluid level and condition. If level is correct, drop the pan and cut open the filter see if you can find any metal particles in the pan and filter. If there is then the transmission is shot. If not, depending on the condition of the fluid, you can consider dropping the valve body and clean it thoroughly. After putting everything back you can perform a relearn of the transmission. This should solve the issue.
This feels very encouraging, but I am no doubt open to additional points of view. Thank you, geniushanbiao!
PS How does one do a transmission relearn?
