Electronic Control System Signature, ISX and QSX15 Engines – FAULT CODE 123

Intake Manifold Pressure Sensor Circuit


Overview

CODE REASON EFFECT
Fault Code: 123
PID: P102
SPN: 102
FMI: 4/4
LAMP: Yellow
SRT: 

Low voltage detected on the intake manifold pressure/temperature sensor.

Derate in power output of the engine.

Intake Manifold Pressure Sensor Circuit
SMALL | MEDIUM | LARGE

Circuit Description

The intake manifold pressure/temperature sensor monitors intake manifold pressure and passes information to the electronic control module (ECM) through the engine harness. If intake manifold pressure becomes too high, it will cause a derate condition.

Component Location

The intake manifold pressure/temperature sensor is located in the intake air manifold toward the front of the engine.

Shop Talk

  • Check for high restriction in the intake air manifold due to a shutdown device in the manifold if the vehicle is equipped with a shutdown device. Do not remove this device. If the engine is operated in a flammable atmosphere, the device is an essential safety feature. Removing it could cause severe personal injury or death.
  • Check for installation of a torque limiting device breakout wiring harness. Temporarily remove the torque limiting device from the engine harness, and install the intake manifold pressure/temperature sensor directly to the engine harness. If Fault Code 123 becomes inactive, inspect the torque limiting device.

Refer to Troubleshooting Fault Code t05-123.

Last Modified:  26-Oct-2010