[jlb27537]

Copy and paste from Cummins engine forum:

P113C-O2 SENSOR POWER SUPPLY CIRCUIT PERFORMANCE.
Theory of Operation

The oxygen sensor is controlled by the smart oxygen module (smart O2 module). This module is a smart device that receives information, such as dew point flag, engine speed, etc., via the J1939 datalink from the primary engine electronic control module (ECM). It provides ECM with the oxygen concentration signal. It also performs its own diagnostics and reports failures back to the primary engine ECM using the J1939 datalink. The ECM then decodes the error message and converts it to a fault code.

When Monitored: Ignition on or engine started.
Set Condition: Supplied voltage to the smart O2 module is below 9.5 volts OR above 13.5 volts.

Possible Causes;
POWER SUPPLY TO SMART O2 MODULE OPEN OR SHORTED TO GROUND
SMART O2 MODULE DEFECTIVE

It was suggested a different thread, to clean the connectors at the O2 sensors. There are 2 of them. Both sensors are in the exhaust, one in front of the Cat converter and 2nd one behind it.

http://www.cumminsforum.com/forum/07...ts-discussion/

Jim