The purpose of checking ECM is to determine whether there is any malfunction of ECM .
IAT sensor connect and Turn ignition switch to ON.
Probe(+) : IAT sensor harness connector NO3.
Probe(-) : Chassis ground.
Verify IAT voltage to change while raising or lowering simulation voltage with scan tool within 0.5~3.5 V
Specification: If the data is changeable as simulation voltage changes,it’s OK
Is Temperature data changed within Specification?
YES
Temporarily install a known good IATS and check for proper operation
If problem is corrected, replace IATS
NO
ECM internal faulty
Repair as necessary and go to "Verification of Vehicle Repair" procedure