Cummins ISX CM870 (2003-06) Fault Code: 486 PID: P129 SPN: 1349 FMI: 1/18 Injector Metering Rail Number 2 Fueling Low – WarningAn unexpectedly low fuel delivery was detected on the rear three cylinders.

The ECM estimates the amount of fuel delivered to each bank by monitoring the crankshaft acceleration pattern as it rotates. This fault is set active if the ECM estimates that the rear bank is receiving insufficient fuel flow.

Possible repairs:

1)Install the original rear fueling actuator.
2)Replace the o-rings.