Exhibit 10.23

SECOND AMENDMENT TO SECOND LIEN CREDIT AGREEMENT

SECOND AMENDMENT(this Amendment), dated as of May 19, 2010, to the Second Lien Credit Agreement, dated as of December 17, 2009 (as amended, restated, amended and restated, supplemented or otherwise modified from time to time, the
Credit Agreement), among HUGHES TELEMATICS, INC., a Delaware corporation (Borrower), the lenders party thereto (the Lenders), PLASE HT, LLC, as administrative agent for the Lenders (in such
capacity, the Administrative Agent) and as collateral agent. Capitalized terms used herein without definition shall have the meanings ascribed to them in the Credit Agreement.

RECITALS

A. Borrower, the Administrative Agent, the Lenders and other parties thereto are party to the Credit Agreement.

B. Borrower has requested that certain amendments be made to the Credit Agreement as set forth herein.

C. The Lenders signatory hereto are willing to consent to the amendments to the Credit Agreement contained herein, on the terms and subject to the conditions set forth herein.

AGREEMENT

NOW, THEREFORE, in consideration of the foregoing and the mutual covenants herein contained, and for other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereby agree as follows:

1.
Amendments to Credit Agreement. As of the Second Amendment Effective Date (as defined below) and subject to the satisfaction of the conditions set forth in Section 2 hereof, Section 4.02 of the Credit Agreement is hereby amended by
deleting the word or at the end of clause (v) in the parenthetical of clause (c) and replacing it with a comma, and adding the following at the end of such clause (vi):

or (vii) the issuance and sale of common stock pursuant to the Stock Purchase Agreement, dated May 13,
2010, by and among the Borrower and each of the purchasers named therein.

2. Effectiveness of this Amendment.
This Amendment shall become effective on and as of the date hereof (the Second Amendment Effective Date) provided that all of the following conditions precedent have been satisfied:

(a) Amendment. The Administrative Agent shall have received this Amendment duly executed and delivered by Borrower
and the Required Lenders;

(b) Costs and Expenses. The Borrower shall have paid all expenses required to
be paid under Section 6 of this Amendment for which invoices have been presented (including the reasonable fees and expenses of legal counsel), in connection with this Amendment (or Borrower shall have made arrangements for the payment thereof
satisfactory to the Administrative Agent);



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(c) First Lien Credit Agreement Amendment. The Administrative Agent
shall have received a copy of a fully executed amendment and consent substantially similar in scope and substance to this Amendment with respect to the Amended and Restated Credit Agreement dated as of April 9, 2007, among Borrower, Morgan
Stanley Senior Funding, Inc., as Administrative Agent and Collateral Agent and the other Lenders a party thereto; and

(d) No Default. No Default or Event of Default shall have occurred and be continuing or will result from the execution, delivery or effectiveness of this Amendment.

3. Representations and Warranties. Borrower represents and warrants as follows:

(a) The Borrower is a duly organized and validly existing Business in good standing under the laws of the jurisdiction of
its organization, (b) has the requisite Business power and authority to own its property and assets and to transact the business in which it is engaged and (c) is duly qualified and is authorized to do business and is in good standing in
each jurisdiction where the ownership, leasing or operation of its property or the conduct of its business requires such qualifications except for failures to be so qualified or authorized which, either individually or in the aggregate, would not
reasonably be expected to have a Material Adverse Effect. No certifications by any Governmental Authority are required for operation of the business of the Borrower that are not in place, except for such certifications or agreements, the absence of
which would not reasonably be expected to have a Material Adverse Effect.

(b) The Borrower has the Business
power and authority to execute, deliver and perform the terms and provisions of the Amendment to which it is party and has taken all necessary Business action to authorize the execution, delivery and performance by it of the Amendment. The Borrower
has duly executed and delivered the Amendment to which it is party, and such Amendment constitutes its legal, valid and binding obligation enforceable in accordance with its terms, except to the extent that the enforceability thereof may be limited
by applicable bankruptcy, insolvency, reorganization, moratorium or other similar laws generally affecting creditors rights and by equitable principles (regardless of whether enforcement is sought in equity or at law).

(c) Neither the execution, delivery by the Borrower of the Amendment or the performance by the Borrower of the Credit
Agreement (as amended by the Amendment), nor compliance by it with the terms and provisions thereof, (a) will contravene any provision of any law, statute, rule or regulation or any order, writ, injunction or decree of any court or Governmental
Authority, except for any such contravention that would not reasonably be expected to have a Material Adverse Effect, (b) will conflict with or result in any breach of any of the terms, covenants, conditions or provisions of, or constitute a
default under, or result in the creation or imposition of (or the obligation to create or impose) any Lien (except pursuant to the Security Documents) upon any of the property or assets of the Borrower or any of its Restricted Subsidiaries pursuant
to the terms of any indenture, mortgage, deed of trust, credit agreement or loan agreement, or any other material agreement, contract or instrument, in each case to which the Borrower or any of its Restricted Subsidiaries is a party or by which it
or any its property or assets is bound or to which it may be subject except for any such conflict that would not reasonably be expected to have a Material Adverse Effect, (c) will violate any provision of the certificate or articles of
incorporation, certificate of formation, limited liability company agreement or by-laws (or equivalent organizational documents), as applicable, of the Borrower or any of its Subsidiaries or (d) will be subject to any limitation on right or
approval from any Governmental Authority.

(d) No order, consent, approval, license, authorization or
validation of, or filing, recording or registration with (except for those that have otherwise been obtained or made on or prior to the Second Amendment Effective Date and which remain in full force and effect on the Second Amendment Effective
Date), or exemption by, any Governmental Authority is required to be obtained or



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made by, or on behalf of, the Borrower to authorize, or is required to be obtained or made by, or on behalf of, the Borrower in connection with, (i) the execution, delivery and performance
of this Amendment, or (ii) the legality, validity, binding effect or enforceability of the Amendment except where failure to obtain or make the same would not reasonably be expected to have a Material Adverse Effect.

(e) No event has occurred and is continuing or will result from the execution and delivery of this Amendment that would
constitute a Default or an Event of Default.

4. Applicable Law. THIS AMENDMENT AND THE RIGHTS AND OBLIGATIONS OF THE
PARTIES HEREUNDER SHALL BE CONSTRUED IN ACCORDANCE WITH AND BE GOVERNED BY THE LAW OF THE STATE OF NEW YORK.

5. WAIVER OF
JURY TRIAL. EACH OF THE PARTIES TO THIS AGREEMENT HEREBY IRREVOCABLY WAIVES ALL RIGHT TO A TRIAL BY JURY IN ANY ACTION, PROCEEDING OR COUNTERCLAIM ARISING OUT OF OR RELATING TO THIS AGREEMENT, THE OTHER CREDIT DOCUMENTS OR THE TRANSACTIONS
CONTEMPLATED HEREBY OR THEREBY.

6. Expenses. Without limiting Borrowers obligations under Section 11.01 of
the Credit Agreement, Borrower hereby agrees to reimburse the Administrative Agent for reasonable and documented out-of-pocket expenses, including the reasonable fees and disbursements of counsel, incurred in connection with this Amendment. The
provisions of Section 11.05 of the Credit Agreement is hereby incorporated by reference herein as if fully set forth and in full force and effect as if written in full herein.

7. Counterparts. This Amendment may be executed in any number of counterparts and by the different parties hereto on separate
counterparts, each of which when so executed and delivered shall be an original, but all of which shall together constitute one and the same instrument. A set of counterparts executed by all the parties hereto shall be lodged with the Borrower and
the Administrative Agent. Delivery of an executed counterpart hereof by facsimile or electronic transmission shall be as effective as delivery of any original executed counterpart hereof.

8. Reference to and Effect on the Credit Documents.

(a) Upon and after the effectiveness of this Amendment, each reference in the Credit Agreement to this
Agreement, hereunder, hereof or words of like import referring to the Credit Agreement, and each reference in the other Credit Documents to the Credit Agreement, thereof or words of like import
referring to the Credit Agreement, shall mean and be a reference to the Credit Agreement as modified and amended hereby.

(b) Except as specifically amended above and as provided for in Section 11 below, the Credit Agreement and all other Credit Documents, are and shall continue to be in full force and effect and are
hereby in all respects ratified and confirmed and shall constitute the legal, valid, binding and enforceable obligations of Borrower to the Administrative Agent and the Lenders, subject to the effects of bankruptcy, insolvency, fraudulent
conveyance, moratorium, reorganization and other similar laws relating to or affecting creditors rights generally and general principles of equity (whether considered in a proceeding in equity or law).

(c) The execution, delivery and effectiveness of this Amendment shall not, except as expressly provided herein, operate as
a waiver of any right, power or remedy of any Agent or any other Lender under any of the Credit Documents, nor constitute a waiver of any provision of any of the Credit Documents.



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(d) To the extent that any terms and conditions in any of the Credit
Documents shall contradict or be in conflict with any terms or conditions of the Credit Agreement, after giving effect to this Amendment, such terms and conditions are hereby deemed modified or amended accordingly to reflect the terms and conditions
of the Credit Agreement as modified or amended hereby.

9. Integration. This Amendment, together with the other Credit
Documents, incorporates all negotiations of the parties hereto with respect to the subject matter hereof and is the final expression and agreement of the parties hereto with respect to the subject matter hereof.

10. Severability. In case any provision in this Amendment shall be invalid, illegal or unenforceable, such provision shall be
severable from the remainder of this Amendment and the validity, legality and enforceability of the remaining provisions shall not in any way be affected or impaired thereby.

[signature pages follow]



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IN WITNESS WHEREOF, the parties have entered into this Amendment as of the date first above
written.



HUGHES TELEMATICS INC.,a Delaware corporationBy:

/s/ CRAIG KAUFMANNName:

Craig KaufmannTitle:

Senior Vice President Finance and Treasurer




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PLASE HT, LLCas LenderBy:

/s/ ANDREW AFRICKName:

Andrew AfrickTitle:

Managing Member




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Accepted, Acknowledged and Agreed:

|                        |  |                  
|----------------------- |  | -----------------
|                       
|PLASE HT, LLC,         
|as Administrative Agent
|                        | 
|By:                     |  | /s/ ANDREW AFRICK
|Name:                   |  | Andrew Africk    
|Title:                  |  | Managing Member  
|                       
|PLASE HT, LLC,         
|as Collateral Agent    
|                        | 
|By:                     |  | /s/ ANDREW AFRICK
|Name:                   |  | Andrew Africk    
|Title:                  |  | Managing Member