2017 CLS550 4 MATIC 9G TRONIC ISSUES
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2017 CLS550 4 matic 2009 C63
2017 CLS550 4 MATIC 9G TRONIC ISSUES
When the engine is already warm and I start the car and go into drive, it initially engages in 1st gear but then immediately shifts to Neutral. This cycle repeats for 3 or 4 attempts before it finally clunks into 3rd gear. Once I’m in 3rd, I can drive normally through gears 3, 4, and 5.
When cold, it drives perfectly normal. Even in gears 3-4-5 no loss of power, shifts completely normal. The only code i am receiving is P073E. The car reverses normally with 0 issues. Transmission fluid, gasket. Replaced in January.
When cold, it drives perfectly normal. Even in gears 3-4-5 no loss of power, shifts completely normal. The only code i am receiving is P073E. The car reverses normally with 0 issues. Transmission fluid, gasket. Replaced in January.
Out Of Control!!
Joined: Apr 2019
Posts: 11,924
Likes: 6,776
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
NOT CASUAL DTC
When the engine is already warm and I start the car and go into drive, it initially engages in 1st gear but then immediately shifts to Neutral. This cycle repeats for 3 or 4 attempts before it finally clunks into 3rd gear. Once I’m in 3rd, I can drive normally through gears 3, 4, and 5.
When cold, it drives perfectly normal.
Even in gears 3-4-5 no loss of power, shifts completely normal.
The only code i am receiving is P073E. The car reverses normally with 0 issues.
Transmission fluid, gasket. Replaced in January.
When cold, it drives perfectly normal.
Even in gears 3-4-5 no loss of power, shifts completely normal.
The only code i am receiving is P073E. The car reverses normally with 0 issues.
Transmission fluid, gasket. Replaced in January.
What type of driving conditions... severe /normal?
Does your engine stores extreme heat??
What does that TCU code tell you?
The valve body is no longer shifting well.
One particular valve is going out of spec.
If you trust your service was done to spec. Right amount of ATF was refilled then "compatible ATF" did not swell valves seals.
>> Then replace conductor plate & clean solenoids screens. Done!
Save your money: no need to futz with adaptations. Tranny does that all by itself.
Last edited by CaliBenzDriver; Jul 15, 2025 at 03:30 PM.
Thread Starter
Newbie
Joined: Feb 2024
Posts: 5
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2017 CLS550 4 matic 2009 C63
What's the current mileage... hi/lo?
What type of driving conditions... severe /normal?
What does that TCU code tell you?
The valve body is no longer shifting well.
If you trust your service was done to spec. Right amount of ATF was refilled.
Then replace conductor plate & clean solenoids screens.
What type of driving conditions... severe /normal?
What does that TCU code tell you?
The valve body is no longer shifting well.
If you trust your service was done to spec. Right amount of ATF was refilled.
Then replace conductor plate & clean solenoids screens.
Normal driving conditions, tend to do pulls from time to time as the ECU is tuned. but not the TCU.
TCU code comes as P073E “unable to engage reverse” which has 0 problems when it comes to reversing.
Out Of Control!!
Joined: Apr 2019
Posts: 11,924
Likes: 6,776
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
DO OBVIOUS FIRST
As a next step... you can try reverting to stock vanilla ECU/TCU. firmware. to get stock condition - That's cheaper than a valve body refurb.
Last edited by CaliBenzDriver; Jul 15, 2025 at 03:36 PM.
Thread Starter
Newbie
Joined: Feb 2024
Posts: 5
Likes: 0
2017 CLS550 4 matic 2009 C63
What's the current mileage... hi/lo?
What type of driving conditions... severe /normal?
Does your engine stores extreme heat??
What does that TCU code tell you?
The valve body is no longer shifting well.
One particular valve is going out of spec.
If you trust your service was done to spec. Right amount of ATF was refilled then "compatible ATF" did not swell valves seals.
>> Then replace conductor plate & clean solenoids screens. Done!
Save your money: no need to futz with adaptations. Tranny does that all by itself.
What type of driving conditions... severe /normal?
Does your engine stores extreme heat??
What does that TCU code tell you?
The valve body is no longer shifting well.
One particular valve is going out of spec.
If you trust your service was done to spec. Right amount of ATF was refilled then "compatible ATF" did not swell valves seals.
>> Then replace conductor plate & clean solenoids screens. Done!
Save your money: no need to futz with adaptations. Tranny does that all by itself.
Would tuning the TCU help? I can bring the ECU to stock but it has been running on the tune since 80,000 miles.
Out Of Control!!
Joined: Apr 2019
Posts: 11,924
Likes: 6,776
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
This is reported as an internal issue. Nothing external with ECU or network... granted faults are purposely misleading.
Simple Extreme heat can totally provide that failure of sticky hard to manage valve body pistons. Next step is clutch are not pressed down firmly so they slip to cause more heat.
