Electronic fault codes active or high counts of inactive fault codes
View and troubleshoot the fault codes with INSITETM electronic service tool. Refer to the ISB,
ISC, ISL, ISDe, and QSB3.3 CM2150 Electronic Control System Troubleshooting and Repair
Manual, Bulletin 4021570.
OEM installed lubricating oil pressure switch, gauge or sensor is malfunctioning or is not in
correct location
Measure the lubricating oil pressure. Refer to Procedure 007-037 in Section 7. Operate the
engine and compare readings to the vehicles OEM installed gauge. Refer to the OEM service manual.
Engine installed lubricating oil pressure sensor/ switch or circuit is malfunctioning (electronic
controlled fuel system)
Measure the lubricating oil pressure. Refer to Procedure 007-037 in Section 7. If equipped with
an oil pressure sensor, monitor the oil pressure with IN SITETM. Operate the engine and compare
readings . If necessary, replace the oil pressure/ sensor switch. See Procedure 019-066 in Section
19 in the ISB, ISC, ISL, ISDe, and QSB3.3 CM2150 Electronic Control System Troubleshooting and Repair Manual, Bulletin 4021570.
Engine installed lubricating oil pressure sensor/ switch or circuit is blocked
Check if sealant is blocking the oil pressure sensor/ switch port by removing the font gear cover. Refer to Procedure 001-031 in Section 1.
Lubricating oil level is above or below specification
Check the oil level. Add or drain oil, if necessary. Refer to Procedure 007-037 and Procedure
007-009 in Section 7.
Lubricating oil leak (external)
Inspect the engine for external oil leaks. Tighten the capscrews, pipe plugs, and fittings. Replace
gaskets, if necessary. Refer to Procedure 007-048 in Section 7.
Lubricating oil does not meet specifications for operating conditions
Change the oil and filters. Refer to Procedure 007-037 in Section 7. See the Owners Manual and/
or Operation and Maintenance Manual for the engine being serviced for oil specifications.
Lubricating oil is contaminated with coolant or fuel
Refer to the Lubricating Oil Contaminated symptom tree.
Engine angularity during operation exceeds specification
Refer to to the engine specification data sheets for angularity specifications for the engine being serviced.
Coolant temperature is above specification
Refer to the Coolant specification Temperature above normal- Gradual Overheat symptom tree.
Lubricating oil filter plumbing not routed correctly
Verify the routing of the lubricating filter plumbing is correct. Refer to Procedure 007-092 in Section 7.
Main oil pressure regulator is malfunctioning
Check the main oil pressure regulator assembly. Refer to Procedure 007-029 in Section 7.
Lubricating oil suction or transfer tube is loose or broken, or the gasket or a-rings are leaking
Remove and inspect the oil pan or suction tube. Refer to Procedure 007-025 in Section 7.
Lubricating oil pump is malfunctioning
Inspect the lubricating oil pump. Refer to Procedure 007-031 in Section 7.
Incorrect lubricating oil pump installed
Check if the correct lubricating oil pump part number is installed. Refer to Procedure 007-031 in
Section 7 (For example a four cylinder pump in a six cylinder engine). See the appropriate parts
manual and/or the QuickServe® Online Internet Website. If necessary replace the oil pump.
Lubricating oil cooler is plugged
Check the oil cooler. Refer to Procedure 007-003 in Section 7.
Lubricating oil temperature is above specification
Refer to the Lubricating Oil Temperature Above Specification symptom tree.
Piston cooling nozzles are damaged or are not installed correctly
Check the piston cooling nozzles for damage and correct installation. Refer to Procedure 001-046 in
Section 1.
Internal engine damage or internal lubricating oil leak
Analyze the lubricating oil. Inspect the oil filter. Refer to Procedure 007-048 and Procedure
007-083 in Section 7 to locate an area of probable damage. Places for probable damage include
internal cup plugs, main bearings, rod bearings, cam bushings and rocker levers.
