TSB210266-111020

11/30/22, 8:46 PM
Fault Code 7327 Closed Crankcase Ventilation (CCV) Breather Troubleshooting
Technical Service Bulletin
Technical Service Bulletin: TSB210266
Released Date: 10-Nov-2022
Fault Code 7327 Closed Crankcase Ventilation (CCV) Breather Troubleshooting
Fault Code 7327 Closed Crankcase Ventilation
(CCV) Breather Troubleshooting
Warranty Statement
The information in this document has no effect on present warranty coverage or repair practices,
nor does it authorize TRP or Campaign actions.
Contents
Product Affected
ISX12N CM2380 X120B
Issue Summary
Closed crankcase ventilation (CCV) breather assembly lower bearing corrosion, damage, and/or
debris not allowing the CCV motor to achieve functional speed.
Symptom:
Fault Code 7327: Engine Crankcase Breather Oil Separator Speed - Data Valid But Below
Normal Operating Range - Moderately Severe Level
Root Cause:
CCV housing lower bearing corrosion, damage, and/or debris
Verification
Verify Fault Code 7327 is present.
Standard Fault Code 7327 troubleshooting has been completed with no trouble found.
Before final step of replacing CCV motor, visually inspect CCV housing lower bearing for
corrosion, damage, and/or debris. See Figures 1 and 2 below.
https://quickserve.cummins.com/qs3/pubsys2/xml/en/tsb/2021/tsb210266.html
1/3
11/30/22, 8:46 PM
Fault Code 7327 Closed Crankcase Ventilation (CCV) Breather Troubleshooting
Figure 1, CCV Housing Lower Bearing Face Moderate Corrosion and Heavy Debris (Top View).
Figure 2, CCV Housing Lower Bearing Face Heavy Corrosion and Light Debris (Top View).
https://quickserve.cummins.com/qs3/pubsys2/xml/en/tsb/2021/tsb210266.html
2/3
11/30/22, 8:46 PM
Fault Code 7327 Closed Crankcase Ventilation (CCV) Breather Troubleshooting
Figure 3, CCV Housing Lower Bearing Sseparated with Bearing Components Missing (Top
View).
Resolution
If visual inspection shows lower bearing corrosion and/or debris, replace crankcase breather
assembly. See ISX12N CM2380 X120B Service Manual, Bulletin Number 5504152. Refer to
Procedure 003-024 in Section 3. (/qs3/pubsys2/xml/en/procedures/525/525-003-024.html)
 CAUTION 
Never apply more than 34.5 kPa [ 5 psi ] to any tube with a check valve. Unregulated shop
air pressure can damage the check valve internally.
If visual inspection shows lower bearing separated with missing bearing components (Figure 3),
perform clean and inspect for reuse section of crankcase ventilation water drain tube procedure.
See ISX12N CM2380 X120B Service Manual, Bulletin Number 5504152. Refer to Procedure 003024 in Section 3. (/qs3/pubsys2/xml/en/procedures/525/525-003-024.html)
Document History
Date
Details
2021-12-6
Module Created
2022-11-10
Added Figure 3 and caution.
Last Modified: 10-Nov-2022
https://quickserve.cummins.com/qs3/pubsys2/xml/en/tsb/2021/tsb210266.html
3/3