CM870 and ISX Engines – FAULT CODE 2554

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Overview

Exhaust Gas Pressure Sensor Circuit – Data Erratic, Intermittent, or Incorrect SMALL | MEDIUM | LARGE

Circuit Description

The exhaust gas pressure sensor is used by the electronic control module (ECM) to monitor the engine exhaust gas pressure. This value is used by the ECM for engine emissions control.

Component Location

The exhaust gas pressure sensor is located above the front section of the exhaust manifold and is plumbed into the exhaust manifold between the Number 1 and Number 2 cylinders. The exhaust gas pressure sensor is mounted to an exhaust gas pressure sensor adapter that is secured to the engine above the exhaust manifold. An exhaust gas pressure tube is mounted between the exhaust gas pressure sensor adapter and the exhaust manifold to separate the exhaust gas pressure sensor from the heat of the exhaust manifold. Refer to Procedure 100-002 (Engine Diagrams) in Section E for a detailed component location view.

Shop Talk

At key-on, before the engine starts, the sensor readings for barometric pressure, engine oil pressure, and intake manifold pressure are compared with exhaust gas pressure. This fault code occurs if the exhaust gas pressure sensor reading is different from any two of the other three. This check is only done once after the keyswitch is turned on and before the engine is started. The engine oil temperature must also be at least 7°C [45°F] for this check to run.

Shop exhaust fans can cause this fault code to come active. Turn exhaust fans off when troubleshooting this fault code.

In some cases, a plugged exhaust gas pressure sensor tube can also cause this fault code.

Refer to Troubleshooting Fault Code t05-2554