ISB/ISBe Series Engines – FAULT CODE 123

  Printable Version

Overview

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 the intake manifold pressure becomes too high, it will cause a derate condition.

Component Location

The intake manifold pressure/temperature sensor is located on the intake air manifold.

Shop Talk

• Determine if engine is being fueled from an alternate fuel source.
• Confirm that the correct intake manifold pressure/temperature sensor part number is being used.
• Confirm that the correct turbocharger is being used.
• If it is suspected that cold intake air is the cause of the high intake manifold pressure, test the engine with warm intake air.
• Inspect the intake manifold pressure/temperature sensor circuit for signs of tampering. Remove any extra wires from the circuit.
• If Fault Code 123 and 352 are active, then begin troubleshooting Fault Code 352 first.

Refer to Troubleshooting Fault Code t05-123