CM2150 Electronic Control System – FAULT CODE 2373

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Overview

ISB, ISC, and ISL – Exhaust Gas Pressure Circuit SMALL | MEDIUM | LARGE

Circuit Description

The exhaust gas pressure sensor is used to measure exhaust gas pressure in the exhaust manifold. This information is used by the electronic control module (ECM) to control emissions and exhaust gas recirculation (EGR) valve operation. The ECM provides a 5 volt supply to the exhaust gas pressure sensor on the sensor supply circuit. The ECM also provides a ground on the sensor return circuit. The exhaust gas pressure sensor provides a signal to the ECM on the exhaust gas pressure sensor signal circuit. This sensor signal voltage changes based on the pressure in the exhaust manifold.

Component Location

The exhaust gas pressure sensor is located above the front section of the exhaust manifold and is plumbed into the exhaust manifold. Refer to Procedure 100-002 (Engine Diagrams) in Section E for a detailed component location view.

Conditions for Running the Diagnostics

This diagnostic runs continuously when the keyswitch is in the ON position.

Conditions for Setting the Fault Codes

The ECM detects that the exhaust gas pressure signal voltage is greater than 4.75-VDC for more than 4 seconds.

Action Taken When the Fault Code is Active

• The ECM illuminates the amber CHECK ENGINE light immediately when the diagnostic runs and fails.
• A default value is used of the exhaust gas pressure reading.

Conditions for Clearing the Fault Code

The ECM will turn off the amber CHECK ENGINE light immediately after the diagnostic runs and passes.

Shop Talk

Verify the electronic control module (ECM) calibration is correct. Check the calibration revision history found on QuickServe® Online for applicable fixes to the calibration stored in the ECM. If necessary, recalibrate the ECM. Refer to Procedure 019-032 (ECM Calibration Code) in Section 19 in the corresponding Troubleshooting and Repair Manual for the engine being serviced.

The exhaust gas pressure sensor shares supply and return wires in the engine harness with other sensors. Opens and shorts in the engine harness can cause multiple fault codes to be active.

Possible causes of this fault code include:

• An open return circuit in the engine harness, connectors, or sensor
• A signal wire shorted to sensor supply or battery voltage.

Refer to Troubleshooting Fault Code t05-2373