Some 2013 Ford E-350 and E-450 vans equipped with a 6.8L diesel engine may exhibit an illuminated wrench lamp with DTC P061A setting after SEIC (stationary elevated idle control) operation is disabled. The SEIC boosts idle speed when using PTO (power take off).

Apparently, the remedy simply involves reprogramming the PCM to the latest calibration using IDS release 84.00 and higher.