VALVE-CHECK 4851097 - Caterpillar

Introduction
The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified below.Problem
The ECM will periodically re-calibrate the electronic unit injectors. There is no indication to the operator that the ECM is re-calibrating the electronic unit injectors. Turning the keyswitch to the OFF position stops the flow of information to the Electronic Control Module (ECM). If the information flow to the ECM is stopped, while the electronic unit injectors are being trimmed, stored data, such as the injector file checksum, may be corrupted.This action will be logged with the ECM as a "Missing Trim File". Dealers may find this fault statement with the electronic service tool and may look for the trim file to re-flash the ECM. The trim file has not been lost, but the trim file is not recognized by the software.Solution
Re-install the trim file.Use the electronic service tool to perform the Fuel System Verification Test to clear the fault.