CM871 and CM876 Electronic Control Systems, ISX and ISM Engines – FAULT CODE 134

Remote Accelerator Pedal or Lever Position Sensor 1 Circuit – Voltage Below Normal or Shorted to Low Source


Overview

CODE REASON EFFECT
Fault Code: 134
PID: P372
SPN: 974
FMI: 4/4
LAMP: Red
SRT: 

Remote Accelerator Pedal or Lever Position Sensor 1 Circuit – Voltage Below Normal or Shorted to Low Source. Low voltage detected at remote accelerator position signal circuit.

Remote accelerator will not operate. Remote accelerator position will be set to 0 percent.

ISX and ISM – Remote Accelerator Pedal or Lever Position Sensor Circuit
SMALL | MEDIUM | LARGE

Circuit Description

The remote accelerator position sensor is a potentiometer attached to the remote accelerator lever. The remote accelerator position sensor varies the signal voltage to the electronic control module (ECM) as the remote accelerator lever is depressed and released. Low signal voltage is received by the ECM when the remote accelerator lever is at 0 percent. A high signal voltage is received by the ECM when the remote accelerator is at 100 percent. The remote accelerator pedal position circuit contains a remote accelerator pedal position 5 volt supply, remote accelerator pedal position return, and remote accelerator pedal position signal.

When the ECM senses a signal voltage lower than the normal operating range of the sensor, this fault code is set.

Component Location

The remote accelerator pedal or lever location varies with each original equipment manufacturer (OEM). Refer to the OEM service manual.

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 that the remote accelerator pedal signal voltage is less than 0.1-VDC for more than 1 second.

Action Taken When the Fault Code is Active

  • The ECM illuminates 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.

If troubleshooting an intermittent accelerator problem:

The remote accelerator pedal or lever position sensor signal voltage can be monitored with the INSITE™ electronic service tool, while flexing the harness to locate the intermittent connection. Intermittent connections will show up as abrupt changes in signal voltage displayed by INSITE™ electronic service tool.

Possible causes of this fault include:

  • Remote accelerator pedal or lever position signal shorted to engine ground or return wires in the OEM harness or sensor.
  • Failed remote accelerator pedal or lever position sensor.
  • Open circuit in the remote accelerator signal, supply, or return wire in the harness or connectors.

NOTE: The three wires in the remote accelerator position sensor circuit must be twisted together.

Refer to Troubleshooting Fault Code t05-134

Last Modified:  09-Jul-2010