CM870 and ISX Engines – FAULT CODE 595

  Printable Version

Overview

Turbocharger Number 1 Speed High Circuit SMALL | MEDIUM | LARGE

Circuit Description

The turbocharger speed sensor is a variable reluctance speed sensor. It consists of a coil of wire and an iron core. The ECM provides power to the sensor and the sensor generates a signal as the turbocharger shaft spins. The target on the turbocharger shaft is a ground flat in the center of the shaft.

Component Location

The turbocharger speed sensor is mounted in the center housing of the turbocharger. Refer to Procedure 100-002 for a detailed component location view.

Shop Talk

NOTE: This fault code may become active if the protective shipping sticker is not removed from the port located on the end opposite of the connector. When installing a new turbocharger control valve, make sure the adhesive cover is removed.

This fault can come active any time the key is on and the ECM detects turbocharger speed greater than a calibration limit. This fault can be caused by malfunctions in the following components:

• Turbocharger speed sensor
• Engine harness
• ECM power supply or grounds
• Electronic vehicle accessories which emit excessive electromagnetic interference.

This fault becomes inactive any time the ECM detects a valid turbocharger speed.

If the fault occurs intermittently:

• Look for causes of intermittent open circuit or short circuits in the turbocharger speed sensor circuit (including the speed sensor pigtail connector).
• Look for sources of electronic noise such as poorly installed vehicle electronic components.
• Make sure the vehicle chassis grounds are in good condition.
• Make sure the ECM power supply and ground circuits are in good condition and that this power supply is not shared with other vehicle electronics.

Refer to Troubleshooting Fault Code t05-595