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Electronic Control System Signature, ISX and QSX15 Engines – FAULT CODE 489 (INDUSTRIAL)

Auxiliary Speed Input Error


Overview

CODE REASON EFFECT
Fault Code: 489
PID: P191
SPN: 191
FMI: 1/18
LAMP: Yellow
SRT: 

Auxiliary speed frequency on input pin indicates the frequency is below a calibration-dependent threshold.

Engine will only idle.
Auxiliary Speed Input Circuit
SMALL | MEDIUM | LARGE

Circuit Description

The auxiliary speed input is a frequency signal from an auxiliary speed or pressure pickup. It is sent to the electronic control module (ECM) and is used to control the engine speed. Auxiliary reference speed is based on the throttle position.

Component Location

The auxiliary speed or pressure pickup device location is dependent on the OEM application. Use the OEM troubleshooting and repair manual for component location.

Shop Talk

The auxiliary speed governor controls engine speed based on a measured auxiliary speed or pressure.

Refer to Troubleshooting Fault Code t05-489.

Last Modified:  26-Oct-2010
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