4FA0

What Code 4FA0 Means

Code 4FA0 points to a clutch position deviation in the SMG transmission. Along with code 4F40 (insufficient pressure), it's tied to an early failure of the SMG pump electric motor. The fault is intermittent and shows up most often once the transmission is hot.

Symptoms

• When 4FA0 appeared, the car wouldn't start; the transmission shifted between N and 1st gear.
• Later, together with codes 4FA0, 4F40, 4F42, and 2B57: random drops into neutral, usually around 31 mph in 3rd/4th gear, and also at 25 mph.
• COG warnings and a transmission problem message / Check Control alert came up.
• When stopped at a red light, the car sometimes died completely with COG on the instrument cluster and the transmission problem light.
• In one case, after dropping into N again, the car went into limp mode.

Diagnosis and Repair

• Replacing the SMG relay and fuse was recommended; the author replaced both.
• An SMG reset (paddle pull) was performed, but the slipping remained.