CM870 and ISX Engines – FAULT CODE 2273

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Overview

EGR Differential Pressure Sensor Circuit for Original Sensor with Side Connector SMALL | MEDIUM | LARGE

EGR Differential Pressure Sensor Circuit for Updated Sensor with Rear Connector SMALL | MEDIUM | LARGE

Circuit Description

The EGR differential pressure sensor has two ports that sense exhaust pressure. The sensor outputs a voltage which represents the pressure difference between the two ports. The ECM uses this pressure to determine how much exhaust gas is flowing in the EGR connection tube to the intake manifold. This information is used to control the EGR valve for correct emission levels.

Component Location

The EGR differential pressure sensor is mounted to the air intake manifold between cylinders three and four. Refer to Procedure 100-002 for a detailed component location view.

Note: The original sensor is connected to the engine harness through a short pigtail harness. The pigtail harness is permanently affixed to the original sensor. Do not try to remove the connector that is attached to the origninal sensor body or damage to the sensor will result.

Shop Talk

The EGR differential 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. Before troubleshooting, check for multiple fault codes.

Possible causes of this fault code include:

• Open return circuit in the harness, connectors, or sensor
• Signal circuit shorted to sensor supply or battery voltage
• Supply circuit shorted to battery voltage.

Refer to Troubleshooting Fault Code t05-2273