2009 420 es/auto shifting problem
I have the 2009 420 that I'm having a weird shifting issue with. And I'm completely lost.
It's the ESP/auto shift model.
ESP Will only shift up when you let it come back down to a idle. Can't get it any higher than 4th. Down shifts is the same, needs to idle down. Shifts from n to 1 and back and n to reverse and back perfectly normal.
Auto mode will not upshift at.
If you unplug the speed sensor is will shift through 1-2-3 in ESP fine at any speed or rpm, will no go into 4 or 5 though and auto won't work.
New oem angle sensor last year. Not throwing the same symptoms as when it messed up before. Have a new sensor ordered.
Any other ideas? All plugs are clean and have dielectric Greese in them. Grounds clean. No codes flashing. Dosent throw the "-" between gears like when a angle sensor normally goes bad.
Last edited by Jacobh; 04-09-2018 at 04:33 PM.