Cummins ISL CM850 (2003-06) Fault Code: 2554 PID: 95 SPN: 1209 FMI: 2 Exhaust pressure sensor circuit – data erratic, intermittent, or incorrect. An error in the exhaust pressure sensor signal was detected by the ECM.

At key-on, before the engine is started, the readings for intake manifold pressure, barometric pressure, and exhaust pressure are compared. This fault code occurs if the exhaust pressure sensor reading is different from the other two. This check is only done once after the keyswitch is turned on. This fault will not occur while the engine is running.

Possible repairs:

1)Replace the exhaust pressure sensor.