Cummins ISC CM2150 (2007-09) Fault Code: 442 PID: 168 SPN: 168 FMI: 0 Battery 1 Voltage - Data Valid but Above Normal Operational Range - Moderately Severe Level. ECM supply voltage is above the maximum system voltage level.

Verify the electronic control module (ECM) calibration is correct. Check the calibration revision history found on QuickServe® Online for applicable fixes to the calibration stored in the ECM. If necessary, recalibrate the ECM.

This fault code is logged when the ECM battery supply voltage exceed 36-VDC. Causes of this fault code include:

1)Faulty alternator or regulator that is overcharging the system
2)Batteries connected in series instead of parallel

Possible repairs:

1)Install the battery system correctly.
2)Repair or replace the alternator, regulator, and/or the OEM wiring to the alternator.