722.9, 0894 code, sudden jolting under mild acceleration

[Davidiot]

Hi,

I have a 2007 SL 500. Suddenly started experiencing trouble with jolting while applying mild to moderate throttle at speed. Pulled codes, erased everything on engine and transmission. Drove until problem manifested itself, checked codes again, the code is 0894, gear is implausible or lock up is slipping.

Dropped the pan, no chunks or bits.

Does someone recognize this?
Many thanks

 

[John Laidlaw]

When was the ATF last changed?

 

[LostKiwi]

It sounds like either the TC lockup clutch is failing or the speed sensor is giving bad readings.

 

[Davidiot]

Thanks, the oil was brown,,, pretty nasty in the pan as seen in photos but no shavings or evidence of mechanical damage. I cleaned the solenoids on the TCU/valvebody using a magnet and fresh fluid, the car now behaves normally, I am going to change the fluid and filter again in just a few days to make sure to get more of the old stuff out that will now have dissolved in the new fluid, and to make sure old stuff don't clog the filter.

The transmission had been serviced before because it had the updated pan but clearly neglected quite some time until now.

 

[grahamcol]

Well hopefully the actions you've already done have fixed the problem