Cummins ISX CM870 (2003-06) Fault Code: 431 (SSS) PID: S230 SPN: 558 FMI: 2/2 Accelerator Pedal Idle Validation Circuit – data incorrect. Voltage detected simultaneously on both idle validation and off-idle validation switches.

SSS Goes to 70-fc431sss

Possible causes:

1)A open circuit on either the idle validation on-idle or off-idle signal circuits, a loose connection, uncalibrated accelerator pedal assembly, or miswired idle validation switch.
2)Since the solid state sensor switch (SSS) uses an integrated circuit to output idle and off-idle SIGNALs, the internal resistance can not be checked with a multimeter as it is for the integrated sensor switch and nonintegrated sensor switch.
3)When installing a new accelerator pedal assembly, it must be calibrated before operating the engine. To calibrate, turn the keyswitch to the ON position and fully depress and release the pedal three times.

Possible repairs:

1)Connect the SSS to the OEM harness.
2)Replace the SSS.
3)Repair or replace the OEM harness.
4)Replace the ECM.