Amjad007

Hello all,
This problem is driving me crazy.
I am facing hard dowshifts that keeps my engine at high RPMs. I don't think it is limp mode because it shifts normal after.
What's more frustrating is that the problem comes and goes.. I really cannot know if it's fixed or not.
I recently changed the valve body / conductor plate / accelerator pedal / transmission oil and filter. And adaptive learning was reset using STAR.
It's a 2003 E500 W211 5G.
The only error code I get in STAR is P2222
The car shifts perfectly except when this happens.
Have anyone faced similar symptoms? Help !

dvenneman

researched the code and it is a general fault code and it indicates that your nitrous of oxides are outside of range. However, web search suggests most commonly found in diesel. https://repairpal.com/obd-ii-code-p2...ge-performance

Amjad007

My car runs on 95 oct Petrol not diesel. Someone suggested changing the plug of conductor plate as it might have an internal leak that causes the harsh downshifts, costs around 30$ so not a big deal.
Can NOX2 sensors cause harsh downshifting? cuz to be honest I'm tired of throwing parts without fixing the problem.

juanmor40

If the conductor plate was recently changed, the plug on the conductor plate must have been removed first and HOPEFULLY

• Checked for oil presence
• Cleaned anyways with electronic contact cleaner
• Installed properly; otherwise, it may now have a leak that was not there earlier,

if you have STAR, or XEntry, can you isolate the error code to a specific module?

Amjad007

I personally don't have STAR but I'll ask my mechanic to check that. I am not sure if the plug was cleaned and I don't think it was.

Amjad007

I thought of a theory if anyone could confirm it can be a possibility.

So, it seems that the trigger of this problem is when I fully press the accelerator pedal. I am thinking that the throttle gets stuck wide open after fully pressing the pedal and mess up the gears by downshifting.

Can this be a possibility?

cetialpha5

You're grasping at straws. Change the connector.

Amjad007

My mechanic told me that it was already changed last time but I will visit him tomorrow and make him remove it to check and replace it.
Will be updating here, thanks.

Amjad007

Quick update, I got the codes read by STAR, it showed P2222/ P2221/ P2220 ( Transmission oil temperature sensor )
I changed the connector and the problem still exists. Any suggestions?

juanmor40

Did you delete the codes after changing the connector?

Typically,
1 - diagnose error by checking codes
2 - fix whatever is wrong
3 - DELETE all error codes
4 - Start the vehicle, drive if possible, for a few miles/km
5 - check error codes again, if any back to 1
6 - if no codes, and car drives well. Cleanup and enjoy your ride

Amjad007

Quick update, I just got out from the mechanic garage. He said that the ATF pan is full of steel parts and that my transmission clutches are going bad. He advised me to change my whole transmission/ATF + filter/ conductor plate / valve body. All for around 800$ and from a japan imported car (clean one)