CM2150 Electronic Control System – FAULT CODE 431

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Overview

Accelerator Pedal or Lever Idle Validation Circuit SMALL | MEDIUM | LARGE

Circuit Description

The idle validation switch is used by the electronic control module (ECM) to indicate when the accelerator pedal or lever 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 or lever 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 or lever assembly.

Conditions for Running the Diagnostics

This diagnostic runs continuously when the keyswitch is in the ON position.

Conditions for Setting the Fault Codes

The ECM detects a signal voltage detected simultaneously on both the idle validation and off-idle validation switches. Voltage will only be detected on one of the circuits.

Action Taken When the Fault Code is Active

• The ECM will illuminate the red STOP ENGINE light immediately when the diagnostic runs and fails.

Conditions for Clearing the Fault Code

The ECM will turn off the red STOP ENGINE light immediately after the diagnostic runs and passes.

Shop Talk

Verify the electronic control module (ECM) calibration is correct. Check the calibration revision history found on QuickServe® Online for applicable fixes to the calibration stored in the ECM. If necessary, recalibrate the ECM. Refer to Procedure 019-032 (ECM Calibration Code) in Section 19 in the corresponding Troubleshooting and Repair Manual for the engine being serviced.

• This fault code is usually caused by an open circuit on either the idle validation on-idle or the idle validation off-idle signal circuit, a loose connection, uncalibrated accelerator pedal or lever assembly, or miswired idle validation switch.
• When installing a new accelerator pedal or lever assembly, it must be calibrated before operating the engine. To calibrate the new accelerator pedal or lever assembly, turn the keyswitch to the ON position and fully depress and release the pedal or lever three times.

Refer to Troubleshooting Fault Code t05-431