CAT 3406E (Prefix 5DS or 1LW) Fault Code: 36 PID: 84 SPN: FMI: 8 Vehicle Speed signal out of range

Posted by PerDiezel Solutions on January 13, 2026

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

CAT 3406E (Prefix 5DS or 1LW) Fault Code: 36 PID: 84 SPN: FMI: 2 Vehicle Speed signal invalid

CAT 3406E (Prefix 5DS or 1LW) Fault Code: 35 PID: 190 SPN: FMI: 0 Engine Overspeed Warning

CAT 3406E (Prefix 5DS or 1LW) Fault Code: 34 PID: 190 SPN: FMI: 2 Primary Engine Speed Loss of Signal

CAT 3406E (Prefix 5DS or 1LW) Fault Code: 32 PID: 91 SPN: FMI: 8 Throttle Position Invalid

CAT 3406E (Prefix 5DS or 1LW) Fault Code: 31 PID: 84 SPN: FMI: 1 Vehicle Speed loss of signal

CAT 3406E (Prefix 5DS or 1LW) Fault Code: 29 PID: 30 SPN: FMI: 13 PTO Throttle out of calibration

WARNING!