SC993

What it means

Engine software error. Confirm the exact subcode against the FSM for this serial — meaning can shift by generation.

Likely causes

• Engine-side log. Flash engine firmware if it repeats.

1. 1Read historySP5-990. Note the subcode and anything logged in the same minute. The standing number is often the last, not the first.
2. 2I/O then FRUSP5-803 / 5-804 on the related sensor or motor. Likely FRU: Engine firmware.

Parts to have on the truck

• Engine firmware

Related codes