981303 Mercedes Fault Code :
Read the description of 981303 in ACM02T and the engine lights up for ACM02T - Exhaust aftertreatment (17A03) code, there are some possible causes for it.
The voltage supply of component '17B16 (NOx sensor upstream of selective catalytic reduction) / NOx sensor' or '17Y02: Ventil Heizung AdBlue-Tank' has short circuit to positive.