ISB/ISBe Series Engines – FAULT CODE 551

Idle Validation Switch Circuit


Overview

CODE REASON EFFECT
Fault Code: 551
PID: S230
SPN: 558
FMI: 4
LAMP: Yellow
SRT: 

Idle validation signals on pins indicate no voltage detected on either pin.

Engine will possibly only idle.

Idle Validation Switch Circuit
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Circuit Description

The idle validation switch 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 by the accelerator pedal manufacturers to switch from on-idle to off-idle at the correct accelerator pedal position.

Component Location

The idle validation switch is located on the accelerator pedal assembly.

Shop Talk

This fault code is usually caused by a loose connection, uncalibrated accelerator pedal, or miswired idle validation switch. A bad ground on pin A (or pin 1) of the idle validation switch can also cause this fault.

Refer to Troubleshooting Fault Code t05-551

Last Modified:  26-Oct-2010