CM870 and ISX Engines – FAULT CODE 431

Accelerator Pedal Idle Validation Circuit


Fault Code: 431
PID: S230
SPN: 558
FMI: 2/2
LAMP: Amber

Accelerator Pedal Idle Validation Circuit – data incorrect. Voltage detected simultaneously on both idle validation and off-idle validation switches.

No effect on performance.

Accelerator Pedal Idle Validation Circuit

Circuit Description

The idle validation switch is used by the electronic control module (ECM) to indicate when the accelerator pedal is released (on-idle) or depressed (off-idle). The switch is adjusted at the factory to switch from on-idle to off-idle at the correct accelerator pedal position. The switch return is a shared return with other OEM cab switches.

Component Location

The integrated sensor switch (ISS) is located on the accelerator pedal assembly.

Shop Talk

  • This fault code is usually caused by an open circuit on either the idle validation on-idle or off-idle signal circuit, a loose connection, uncalibrated accelerator pedal assembly, or miswired idle validation switch.
  • The integrated sensor switch (ISS) has a different internal resistance specification (125 ohms) than the nonintegrated sensor switch (NISS).
  • 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.

Refer to Troubleshooting Fault Code t05-431iss

Last Modified:  01-Sep-2010