CAT 3406E (Prefix 5DS or 1LW) Fault Code: 24 PID: 100 SPN: FMI: 3 Oil Pressure voltage high

Posted by PerDiezel Solutions on January 13, 2026

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

•The signal voltage from the engine oil pressure sensor is greater than 4.95 VDC for more than eight seconds.
•The ECM has been powered for at least two seconds.
•The 168-01 Low ECM Battery Power is not active.
•The 232-03 5 Volt Supply voltage high is not active.
•The 232-04 5 Volt Supply voltage low is not active.
•The engine is not running or the engine coolant temperature is greater than 38 °C (100 °F).

If you have this code inactive but has happened recently or frequently, please clear the code, turn the key on, and then wiggle the sensor to attempt to generate the code. If you don’t generate the code, there could be a problem with high crankcase pressure or a wiring problem with the sensor. A plugged crankcase breather will cause excessive crankcase pressure, which leas to crankshaft seal failure, which leads to piston ring failure. All of this will increase your crankcase pressure. Sticking of the pistons can also cause this code, and cylinder liners should be inspected for scoring/scuffing.

Probable Causes:

1) ECM Connection/Harness
2) Crankcase breather plugged
3) Oil pressure sensor
4) Oil pressure sensor harness
5) ECM Failure

CAT 3406E (Prefix 5DS or 1LW) Fault Code: 21 PID: 232 SPN: FMI: 4 5 Volt Supply voltage low

CAT 3406E (Prefix 5DS or 1LW) Fault Code: 21 PID: 232 SPN: FMI: 3 5 Volt Supply voltage high

CAT 3406E (Prefix 5DS or 1LW) Fault Code: 21 PID: 41 SPN: FMI: 4 8 Volt Supply voltage low

CAT 3406E (Prefix 5DS or 1LW) Fault Code: 21 PID: 41 SPN: FMI: 3 8 Volt Supply voltage high

CAT 3406E (Prefix 5DS or 1LW) Fault Code: 14 PID: 122 SPN: FMI: 6 Med/High Retarder current high

CAT 3406E (Prefix 5DS or 1LW) Fault Code: 14 PID: 122 SPN: FMI: 5 Med/High Retarder current low

WARNING!