4.
While changing the frequency up or down in sensor output and simulation mode,check the chage of vehicle speed.
a.
Specification: If the vehicle speed changes as simmulation frequency chage,it is OK
Turn ignition switch to OFF and disconnect VSS harness connector.
Turn ignition switch to ON.
Probe(+) : VSS harness connector NO2.
Probe(-) : Chassis ground.
While changing the frequency up or down in sensor output and simulation mode,check the chage of vehicle speed.
Specification: If the vehicle speed changes as simmulation frequency chage,it is OK
Is MAP sensor data changeable Specification?
YES
Temporarily install a known good VSS and check for proper operation
If problem is corrected, replace VSS
NO
ECM internal faulty
Repair as necessary and go to "Verification of Vehicle Repair" procedure
