CMI-M7A9X-07

ISX12N Continuous Flow Valve
(CFV) Quality Defect.
6/23/18
Cummins Westport Confidential
CFV Quality Defect
 Symptoms: The anticipated failures are fault codes 3436 and 3437 and possibly impact to
engine performance. Further testing planned the week of 6/25 to understand all potential
symptoms.
 Issue: A change to the thread forming process at the supplier resulted in low clamping force on
an internal component in the CFV. The internal component is retained by 6 capscrews. 1 or more
of these capscrews could reach the desired torque due to increased loading at the threads prior
to the component reaching the desired clamping force. If the desired clamping force is not
achieved this may increase the risk of an internal failure in the CFV. The anticipated failure is a
CFV that slow response achieving desired gas flow resulting in a fault code and check engine
light.
 Correction: Internal repairs of the CFV are not possible. Replacement of the CFV is required in
the event of an internal failure. Out of an abundance of caution it is recommended to replace
CFVs proactively on engines that are still at the OEMs while CWI and the supplier continue to
asses the impact of the defect to long term CFV durability.
Cummins Westport Confidential
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