<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-04-30</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0001735707</issuerCik>
        <issuerName>Garrett Motion Inc.</issuerName>
        <issuerTradingSymbol>GTX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001627400</rptOwnerCik>
            <rptOwnerName>Attestor Value Master Fund, LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>UGLAND HOUSE, PO BOX 309</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>GRAND CAYMAN, KY1-1104</rptOwnerCity>
            <rptOwnerState>E9</rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription>CAYMAN ISLANDS</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Member of 10% owner group</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001830732</rptOwnerCik>
            <rptOwnerName>Attestor Value Fund GP Ltd</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>UGLAND HOUSE, PO BOX 309</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>GRAND CAYMAN, KY1-1104</rptOwnerCity>
            <rptOwnerState>E9</rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription>CAYMAN ISLANDS</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Member of 10% owner group</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001830731</rptOwnerCik>
            <rptOwnerName>Attestor Capital Ltd</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>UGLAND HOUSE, PO BOX 309</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>GRAND CAYMAN, KY1-1104</rptOwnerCity>
            <rptOwnerState>E9</rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription>CAYMAN ISLANDS</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Member of 10% owner group</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001760131</rptOwnerCik>
            <rptOwnerName>Attestor Ltd</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>7 SEYMOUR STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LONDON, W1H 7JW</rptOwnerCity>
            <rptOwnerState>X0</rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription>UNITED KINGDOM</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Member of 10% owner group</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001830250</rptOwnerCik>
            <rptOwnerName>Peters Jan-Christoph</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O  ATTESTOR LIMITED</rptOwnerStreet1>
            <rptOwnerStreet2>7 SEYMOUR STREET</rptOwnerStreet2>
            <rptOwnerCity>LONDON, W1H 7JW</rptOwnerCity>
            <rptOwnerState>X0</rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription>UNITED KINGDOM</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Member of 10% owner group</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2021-04-30</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>3147970</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">On September 20, 2020, Garrett Motion Inc. (the &quot;Issuer&quot;) and certain of its subsidiaries (collectively, the &quot;Debtors&quot;) each filed a voluntary petition for relief under chapter 11 of title 11 of the United States Code (the &quot;Bankruptcy Code&quot;) in the United States Bankruptcy Court for the Southern District of New York (the &quot;Bankruptcy Court&quot;). On April 26, 2021, the Debtors filed an amended Chapter 11 plan of reorganization (the &quot;Plan&quot;) and on April 9, 2021, the Issuer filed a supplement to the Plan (as amended on April 20, 2021 and April 22, 2021, the &quot;Plan Supplement&quot;) with the Bankruptcy Court. On April 26, 2021, the Bankruptcy Court entered an order confirming the Plan (the &quot;Confirmation Order&quot;) and, on April 30, 2021 (the &quot;Effective Date&quot;) the conditions to effectiveness of the Plan were satisfied or waived and the Issuer emerged from bankruptcy.</footnote>
        <footnote id="F2">(Continued from footnote 1) On the Effective Date, all outstanding shares of the Issuer's common stock outstanding prior to the Effective Date were canceled, released, and extinguished, and of no further force or effect and without any need for a holder of such common stock to take further action with respect thereto. Accordingly, this Form 4 shall constitute an exit filing for the Reporting Persons with respect to the Issuer.</footnote>
        <footnote id="F3">These securities of the Issuer are beneficially owned by (a) Attestor Value Master Fund LP, a Cayman Islands exempted limited partnership (&quot;Attestor&quot;), as a result of its direct ownership of the Shares reported herein, (b) Attestor Value Fund GP Limited, a Cayman Islands exempted private limited company (&quot;Attestor GP&quot;), as the sole general partner of Attestor, (c) Attestor Capital Limited, a Cayman Islands exempted private limited company (&quot;Attestor Capital&quot;), as the manager to Attestor GP, (d) Attestor Limited, a private limited company registered in England and Wales (with company number 12080120) (&quot;Attestor Limited&quot;), as the investment manager to Attestor, and (e) Mr. Jan-Christoph Peters, as the sole director and sole indirect shareholder of Attestor Limited. Attestor, Attestor GP, Attestor Capital, Attestor Limited and Mr. Peters are collectively referred to as the &quot;Reporting Persons.&quot;</footnote>
    </footnotes>

    <remarks>The Reporting Persons are jointly filing this Form 4. The Reporting Persons disclaim beneficial ownership of any securities reported by any person except to the extent of their pecuniary interest therein.</remarks>

    <ownerSignature>
        <signatureName>Attestor Value Master Fund LP, acting by Attestor Limited, By: /s/ Jan-Christoph Peters, Name: Jan-Christoph Peters, Title: Authorised Attorney</signatureName>
        <signatureDate>2021-05-03</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Attestor Value Fund GP Limited, By: /s/ Jan-Christoph Peters, Name: Jan-Christoph Peters, Title: Director</signatureName>
        <signatureDate>2021-05-03</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Attestor Capital Limited, By: /s/ Jan-Christoph Peters, Name: Jan-Christoph Peters, Title: Director</signatureName>
        <signatureDate>2021-05-03</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Attestor Limited, By: /s/ Jan-Christoph Peters, Name: Jan-Christoph Peters, Title: Authorised Attorney</signatureName>
        <signatureDate>2021-05-03</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Jan-Christoph Peters, Name: Jan-Christoph Peters</signatureName>
        <signatureDate>2021-05-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
