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

The Engine Control Module (ECM) detects the following conditions:

•The primary engine speed/timing signal was lost and then returned within one second.
•The engine has been running for more than three seconds.
•The engine speed did not pass through the 350 to 500 rpm range.
•Battery voltage is greater than 9 VDC prior to the short or open circuit condition.

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