CAT 3406E (Prefix 1MM or 2WS) Fault Code: 36 PID: SPN: 84 FMI: 8 Vehicle Speed signal out of range
The Engine Control Module (ECM) detects the following conditions:
•The vehicle speed signal indicates that vehicle speed is greater than 127.5 MPH for more than two seconds. •The “VSL Protection” parameter is programmed to a value that is less than 2120 rpm.
Probable Causes:
1) Fuel system restriction (Uncommon, but possible) 2) If speedometer is not accurate, then ECM is not programmed correctly 3) Vehicle speed sensor 4) Vehicle speed sensor wiring 5) ECM Connection/Harness 6) Speedometer failure 7) ECM Failure