SL/R230: 722.9 in limp - DTC 0778 or P0778
Thread Starter
Newbie
Joined: Oct 2014
Posts: 1
Likes: 0
2007 SL550 AMG
722.9 in limp - DTC 0778 or P0778
722.9 in an '07 SL550 with 60K
Limp mode stuck in 2nd gear at all times, sometimes can clear codes and it comes out of limp and drives normal. Already replaced the B1 Brake control Solenoid with no change. Still goes to limp 2nd gear with no upshift with returning P0778 and also see P1737 under another category on my Genisys scanner which has European software which I imagine is related to security system. Scanner data while in limp shows the word "implausible" next to where it says Actual Gear so it don't know what gear it is in. Unit is filled correctly with correct fluid. I'm about to order new valve body from MB parts dept for about $700 wholesale. I'm a mechanic 35+ years professionally, just don't know MB deeply. By the way, I would like to dispell the myth that MB will not sell a complete valve body over the counter. They will. they just ask me to bring my license and registration for car due to security reasons I guess. My question here mainly is does anyone feel that I could solve this by replacing the conductor plate only which would speed up the repair by allowing avoidance of recoding the car at the dealer after I change the valve body?
Thank You
Kevin Huttenlocher
Limp mode stuck in 2nd gear at all times, sometimes can clear codes and it comes out of limp and drives normal. Already replaced the B1 Brake control Solenoid with no change. Still goes to limp 2nd gear with no upshift with returning P0778 and also see P1737 under another category on my Genisys scanner which has European software which I imagine is related to security system. Scanner data while in limp shows the word "implausible" next to where it says Actual Gear so it don't know what gear it is in. Unit is filled correctly with correct fluid. I'm about to order new valve body from MB parts dept for about $700 wholesale. I'm a mechanic 35+ years professionally, just don't know MB deeply. By the way, I would like to dispell the myth that MB will not sell a complete valve body over the counter. They will. they just ask me to bring my license and registration for car due to security reasons I guess. My question here mainly is does anyone feel that I could solve this by replacing the conductor plate only which would speed up the repair by allowing avoidance of recoding the car at the dealer after I change the valve body?
Thank You
Kevin Huttenlocher
Member
Joined: Feb 2013
Posts: 103
Likes: 7
From: South Australia
2004 (MY05) SL55
Not sure about the 722.9 but conductor plate is not an uncommon problem in the 722.6.
I just DIY replaced mine a couple of weeks ago. It wasn't throwing codes or going into limp mode, but I was having some issues that I thought could be related to the speed sensor.
For approx $200 and a few hours of my time I couldn't be happier with the result. Trans is silky smooth now.
I would recommend trying the conductor plate first.
I just DIY replaced mine a couple of weeks ago. It wasn't throwing codes or going into limp mode, but I was having some issues that I thought could be related to the speed sensor.
For approx $200 and a few hours of my time I couldn't be happier with the result. Trans is silky smooth now.
I would recommend trying the conductor plate first.
