C220cdi W203 Auto Gearbox Sticking In 2nd

[www.wildingmotors.co.uk]

Hello, We have a 2002 C220CDI W203 automatic driving us crazy, it sticks in 2nd gear after around 4 miles when the engine is warm. Fault codes read
P220A yn/3 & yn/2 speed sensors implausable, so we have fitted a new gearbox conductor plate with sensors and checked connections and loom for ATF contamination (all dry) , changed the healthy looking ATF and filter yet we still have the same fault and fault codes? The battery voltage is fine. The only other code recorded only occasionaly is P2000 brake pressure? the engine managment light does not appear with the fault and the car resets after switching off and restarting. Our Snap-on Solus Pro records an incorrect 8000rpm on live data when the fault occurs.
Any advice appreciated!
Cheers Ian

 

[television]

Hello Ian and welcome

This evening I will look up other known reasons,,maybe a MB techie will see the post and offer some advice

 

[Ellsy Tanners]

Possibly a wiring issue, you could test the wiring for a problem, disconnect both gearbox and control unit to see if theres a short to ground on the speed sensor wires.

Other than that it only leaves the control unit i reckon.

 

[padrig]

c220cdi in limp mode

hi
i had this fault on my c 220cdi 2002, merc service came out to the car found a break in wiring between boot loom and rear abs/speed sensor.