Cummins ISX CM870 (2003-06) Fault Code: 2554 PID: P95 SPN: 1209 FMI: 2/2 Exhaust Gas Pressure – Data Erratic, Intermittent or Incorrect. The exhaust gas pressure sensor is reading an erratic value.

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.

Possible repairs:

1)Replace the exhaust gas pressure sensor.