UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549





FORM 10-K







|x | ANNUAL REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934.
|- | --------------------------------------------------------------------------------------

For the fiscal year ended December 31, 2015.

OR



| ̈ | TRANSITION REPORT PURSUANT TO SECTION 13 OR 15 (d) OF THE SECURITIES EXCHANGE ACT OF 1934.
|- | ------------------------------------------------------------------------------------------

For the transition period from
to
.

Commission file number of the issuing entity: 333-170231-13

CIK number of the issuing entity: 0001583712





AMERICREDIT
AUTOMOBILE RECEIVABLES TRUST 2013-4

(Exact name of issuing entity as specified in its charter)

Commission File Number of depositor: 333-170231

CIK number of depositor: 0001347185

AFS SENSUB CORP.

(Exact
name of depositor as specified in its charter)

Commission File Number of sponsor: 001-13329

CIK number of sponsor: 0001002761

AMERICREDIT FINANCIAL SERVICES, INC.

(Exact name of sponsor as specified in its charter)







|                                                                                                  |  |                                     
|------------------------------------------------------------------------------------------------- |  | ------------------------------------
|Delaware                                                                                          |  | 46-6893269                          
|(State or other jurisdiction of
incorporation or organization)                                    |  | (I.R.S. employer
identification no.)
|                                                                                                 
|                                                                                                  | 
|AmeriCredit Financial Services, Inc. (as originator)
801 Cherry Street, Suite 3500
Fort Worth, TX |  | 76102                               
|                                                                                                 
|                                                                                                 
|(Address of principal executive offices)                                                          |  | (Zip Code)                          

Registrants telephone number, including area code (817) 302-7000

Securities Registered Pursuant to Section 12 (b) of the Securities Exchange Act of 1934: None

Securities Registered Pursuant to Section 12 (g) of the Securities Exchange Act of 1934: None





Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.    Yes   ̈    No  x

Indicate by check mark
if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.    Yes   ̈    No  x

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by
Section 13 or 15 (d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for
the past 90 days.    Yes  x    No   ̈

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required
to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such
files).    Yes  x    No   ̈

Indicate by check mark if the disclosure of delinquent filers pursuant to Item 405 of Regulation S-K (§229.405 of this chapter) is not contained
herein and will not be contained, to the best of the registrants knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.  [X]

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, or a non-accelerated filer or a smaller reporting company.
See definition of accelerated filer and large accelerated filer in Rule 12b-2 of the Exchange Act. (Check one):



|                        |  |   |  |                           |  |  
|----------------------- |  | - |  | ------------------------- |  | -
|Large accelerated filer |  |  ̈ |  | Accelerated filer         |  |  ̈
|                        |  |   | 
|Non-accelerated filer   |  | x |  | Smaller reporting company |  |  ̈

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the
Act).    Yes   ̈    No  x

State the aggregate market value of the voting and non-voting common equity held by non-affiliates computed by reference to the price at which the common
equity was last sold, or the average bid and asked price of such common equity, as of the last business day of the registrants most recently completed second fiscal quarter.

Not applicable to this registrant









---

List hereunder the following documents if incorporated by reference and the part of the Form 10-K (e.g. Part I,
Part II, etc.) into which the document is incorporated: (1) Any annual report to security holders; (2) Any proxy information statement; and (3) Any prospectus filed pursuant to Rule 424(b) or (c) under the Securities Act of 1933.
The listed documents should be clearly described for identification purposes (e.g., annual report to security holders for fiscal year ended December 24, 1980).

None.

PART I

The following Items have been omitted in accordance with General Instruction J to Form 10-K:



|         |  |                  
|-------- |  | -----------------
|ITEM 1.  |  | BUSINESS         
|         | 
|ITEM 1A. |  | RISK FACTORS     
|         | 
|ITEM 2.  |  | PROPERTIES       
|         | 
|ITEM 3.  |  | LEGAL PROCEEDINGS

ITEM 1B. UNRESOLVED STAFF COMMENTS



|      |  | 
|----- |  | 
|      | 
|None. |  | 

ITEM 4. MINE SAFETY DISCLOSURES



|                |  | 
|--------------- |  | 
|                | 
|Not Applicable. |  | 
|                | 
|PART II         |  | 

The following Items have been omitted in accordance with General Instruction J to Form 10-K:



|         |  |                                                                                      
|-------- |  | -------------------------------------------------------------------------------------
|ITEM 5.  |  | MARKET FOR REGISTRANTS COMMON EQUITY AND RELATED STOCKHOLDER MATTERS                
|         | 
|ITEM 6.  |  | SELECTED FINANCIAL DATA                                                              
|         | 
|ITEM 7.  |  | MANAGEMENTS DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS
|         | 
|ITEM 7A. |  | QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK                           



---

|         |  |                                                                                     
|-------- |  | ------------------------------------------------------------------------------------
|ITEM 8.  |  | FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA                                         
|         | 
|ITEM 9.  |  | CHANGES IN AND DISAGREEMENTS WITH ACCOUNTANTS ON ACCOUNTING AND FINANCIAL DISCLOSURE
|         | 
|ITEM 9A. |  | CONTROLS AND PROCEDURES                                                             
|         | 
|ITEM 9B. |  | OTHER INFORMATION                                                                   

None.

PART III

The following Items have been omitted in accordance with General Instruction J to Form 10-K:



|         |  |                                                                                               
|-------- |  | ----------------------------------------------------------------------------------------------
|ITEM 10. |  | DIRECTORS AND EXECUTIVE OFFICERS AND CORPORATE GOVERNANCE                                     
|         | 
|ITEM 11. |  | EXECUTIVE COMPENSATION                                                                        
|         | 
|ITEM 12. |  | SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT AND RELATED STOCKHOLDER MATTERS
|         | 
|ITEM 13. |  | CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS AND DIRECTOR INDEPENDENCE                      
|         | 
|ITEM 14. |  | PRINCIPAL ACCOUNTANT FEES AND SERVICES                                                        
|         | 
|ITEM 15  |  | EXHIBITS AND FINANCIAL STATEMENT SCHEDULES                                                    

(a)(1)   Not Applicable

(a)(2)   Not Applicable

(a)(3)   As reported
under clause (b)



|(b) | 
|--- | 



|               |  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
|-------------- |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|Exhibit Number |  | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
|               | 
|Exhibit 4.1    |  | Indenture, dated as of August 7, 2013, between AmeriCredit Automobile Receivables Trust 2013-4 and Wells Fargo Bank, National Association, as Trustee and Trust Collateral Agent (incorporated by reference from Exhibit 4.1 of the
Current Report on Form 8-K filed by AmeriCredit Automobile Receivables Trust 2013-4 (File No. 333-170231-13) with the SEC on August 21, 2013).                                                                                                 
|               | 
|Exhibit 4.2    |  | Amended and Restated Trust Agreement, dated as of August 7, 2013, between AFS SenSub Corp., as Seller, and Wilmington Trust Company, as Owner Trustee (incorporated by reference from Exhibit 4.2 of the Current Report on Form 8-K
filed by AmeriCredit Automobile Receivables Trust 2013-4 (File No. 333-170231-13) with the SEC on August 21, 2013).                                                                                                                            
|               | 
|Exhibit 4.3    |  | Sale and Servicing Agreement, dated as of August 7, 2013, among AmeriCredit Automobile Receivables Trust 2013-4, as Issuer, AmeriCredit Financial Services, Inc., as Servicer, AFS SenSub Corp., as Seller, and Wells Fargo Bank,
National Association, as Trust Collateral Agent (incorporated by reference from Exhibit 4.3 of the Current Report on Form 8-K filed by AmeriCredit Automobile Receivables Trust 2013-4 (File No. 333-170231-13) with the SEC on August 21,
2013).



---

|             |  |                                                                                                                                                                                                                                                                                                                                                                                                      
|------------ |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|             | 
|Exhibit 10.1 |  | Purchase Agreement, dated as of August 7, 2013, between AmeriCredit Financial Services, Inc., as Seller and AFS SenSub Corp., as Purchaser (incorporated by reference from Exhibit 10.1 of the Current Report on Form 8-K filed by
AmeriCredit Automobile Receivables Trust 2013-4 (File No. 333-170231-13) with the SEC on August 21, 2013).                                                        
|             | 
|Exhibit 10.2 |  | Lockbox Account Agreement, dated as of August 7, 2013, among JPMorgan Chase Bank, N.A., as Processor, AmeriCredit Financial Services, Inc., and Wells Fargo Bank, National Association, as Trustee (incorporated by reference from
Exhibit 10.2 of the Current Report on Form 8-K filed by AmeriCredit Automobile Receivables Trust 2013-4 (File No. 333-170231-13) with the SEC on August 21, 2013).
|             | 
|Exhibit 10.3 |  | Lockbox Processing Agreement, dated as of August 7, 2013, among AmeriCredit Financial Services, Inc., Wells Fargo Bank, National Association, as Trustee, and Regulus Group II LLC, as Processor (incorporated by reference from Exhibit
10.3 of the Current Report on Form 8-K filed by AmeriCredit Automobile Receivables Trust 2013-4 (File No. 333-170231-13) with the SEC on August 21, 2013).  
|             | 
|Exhibit 31.1 |  | Rule 13a-14(a)/15d-14(a) Certification (Section 302 Certification).                                                                                                                                                                                                                                                                                                                                  
|             | 
|Exhibit 33.1 |  | Managements Assertion Regarding Compliance with Applicable Servicing Criteria concerning servicing activities of AmeriCredit Financial Services, Inc. and its subsidiaries for the year ended December 31, 2015.                                                                                                                                                                                    
|             | 
|Exhibit 33.2 |  | Assessment of Compliance with Applicable Servicing Criteria (Wells Fargo Bank, National Association).                                                                                                                                                                                                                                                                                                
|             | 
|Exhibit 34.1 |  | Report of Independent Registered Public Accounting Firm (Deloitte & Touche LLP).                                                                                                                                                                                                                                                                                                                     
|             | 
|Exhibit 34.2 |  | Report of Independent Registered Public Accounting Firm (KPMG LLP).                                                                                                                                                                                                                                                                                                                                  
|             | 
|Exhibit 35.1 |  | Servicer Compliance Statement of AmeriCredit Financial Services, Inc.                                                                                                                                                                                                                                                                                                                                



|(c) | Not Applicable.
|--- | ---------------

SUBSTITUTE INFORMATION INCLUDED IN ACCORDANCE WITH GENERAL INSTRUCTION J
TO FORM

10-K:

ITEM 1112(b) OF REGULATION AB. (SIGNIFICANT OBLIGORS OF POOL ASSETS)

There is no single obligor that represents more than 10% of the pool assets.



---

ITEM 1114(b)(2) OF REGULATION AB. (CREDIT ENHANCEMENT AND OTHER SUPPORT, EXCEPT FOR CERTAIN DERIVATIVES
INSTRUMENTS (FINANCIAL INFORMATION))

There is no external credit enhancement or other support provider that is liable to provide payments supporting
any notes or certificates issued by the Issuing Entity.

ITEM 1115(b) OF REGULATION AB. (CERTAIN DERIVATIVE INFORMATION (FINANCIAL INFORMATION))

No entity provides any derivative instruments that are used to alter the payment characteristics of the cash flows from the Issuing Entity.

ITEM 1117 OF REGULATION AB. (LEGAL PROCEEDINGS)

As
a consumer finance company, the sponsor is subject to various consumer claims and litigation seeking damages and statutory penalties, based upon, among other things, usury, disclosure inaccuracies, wrongful repossession, violations of bankruptcy
stay provisions, certificate of title disputes, fraud, breach of contract and discriminatory treatment of credit applicants. Some litigation against the sponsor could take the form of class action complaints by consumers and certain legal actions
include claims for substantial compensatory and/or punitive damages or claims for indeterminate amounts of damages.

In July 2014, in connection with an
investigation by the U.S. Department of Justice in contemplation of a civil proceeding for potential violations of the Financial Institutions Reform, Recovery, and Enforcement Act of 1989, General Motors Financial Company, Inc. (General Motors
Financial), immediate parent of the sponsor, was served with a subpoena by the U.S. Department of Justice directing it to produce certain documents relating to its and its subsidiaries and affiliates origination and securitization
of subprime automobile loans since 2007. Among other matters, the subpoena requests information relating to the underwriting criteria used to originate these automobile loans and the representations and warranties relating to those underwriting
criteria that were made in connection with the securitization of the automobile loans. General Motors Financial has subsequently been served with additional investigative subpoenas to produce documents from state attorneys general and other
governmental offices relating to its retail auto loan business and securitization of auto loans. In October 2014, General Motors Financial received a document request from the Securities and Exchange Commission in connection with its investigation
into certain practices in subprime auto loan securitization. These investigations are ongoing and could in the future result in the imposition of damages, fines or civil or criminal claims and/or penalties.

No assurance can be given that the ultimate outcome of the investigations or any resulting proceedings would not materially and adversely affect General
Motors Financial or any of its subsidiaries and affiliates, including the servicer, or the interests of the noteholders or the servicers ability to perform its duties under the transaction documents.

On June 18, 2014, a group of institutional investors filed a civil complaint in the Supreme Court of the State of New York, New York County, against
Wells Fargo Bank, N.A., in its capacity as trustee under 276 residential mortgage backed securities, (RMBS), trusts, which was later amended on July 18, 2014, to increase the number of trusts to 284 RMBS trusts. On November 24,
2014, the plaintiffs filed a motion to voluntarily dismiss the state court action without prejudice. That same day, a group of institutional investors filed a civil complaint in the United States District Court for the Southern District of New York
against Wells Fargo Bank, N.A., alleging claims against the bank in its capacity as trustee for 274 residential mortgage backed securities RMBS trusts, (the Complaint). In December 2014, the plaintiffs motion to voluntarily dismiss
their original state court action was granted. As with the prior state court action, the complaint is one of six similar complaints filed contemporaneously against RMBS trustees (Deutsche Bank National Trust Company, Deutsche Bank Trust Company
Americas, Citibank N.A., HSBC Bank USA, National Association, The Bank of New York Mellon and U.S. Bank National Association) by a group of institutional investor plaintiffs. The complaint against Wells Fargo alleges that Wells Fargo caused losses
to investors and asserts causes of action based upon, among other things, Wells Fargos alleged failure to (i) enforce repurchase obligations of mortgage loan sellers for purported breaches of representations and warranties,
(ii) notify investors of alleged events of default purportedly caused by breaches by mortgage loan servicers, and (iii) abide by appropriate standards of care following alleged events of default. Relief sought includes money damages in an
unspecified amount, reimbursement of expenses, and equitable relief. Other cases alleging similar causes of action have previously been filed against Wells Fargo and other trustees by RMBS investors in these and other transactions.



---

There can be no assurances as to the outcome of the litigation, or the possible impact of the litigation on Wells
Fargo or the RMBS trusts. However, Wells Fargo denies liability and believes that it has performed its obligations under the RMBS trusts in good faith, that its actions were not the cause of losses to investors and that it has meritorious defenses,
and it intends to contest the plaintiffs claims vigorously.

ITEM 1119 OF REGULATION AB. (AFFILIATIONS AND CERTAIN RELATIONSHIPS AND RELATED
TRANSACTIONS)

Information required by Item 1119 of Regulation AB has been omitted from this report on Form 10-K in reliance on the
Instruction to Item 1119.

ITEM 1122 OF REGULATION AB. COMPLIANCE WITH APPLICABLE SERVICING CRITERIA.

The following documents are filed as part of this report.



|               |  |                                                                                                                                                                                                                  
|-------------- |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|Exhibit Number |  | Description                                                                                                                                                                                                      
|               | 
|Exhibit 33.1   |  | Managements Assertion Regarding Compliance with Applicable Servicing Criteria concerning servicing activities of AmeriCredit Financial Services, Inc. and its subsidiaries for the year ended December 31, 2015.
|               | 
|Exhibit 33.2   |  | Assessment of Compliance with Applicable Servicing Criteria (Wells Fargo Bank National Association).                                                                                                             
|               | 
|Exhibit 34.1   |  | Report of Independent Registered Public Accounting Firm (Deloitte & Touche LLP).                                                                                                                                 
|               | 
|Exhibit 34.2   |  | Report of Independent Registered Public Accounting Firm (KPMG LLP).                                                                                                                                              

The Servicer has complied, in all material respects, with the Applicable Servicing Criteria.

ITEM 1123 OF REGULATION AB, SERVICER COMPLIANCE STATEMENT

The following documents are filed as part of this report.



|               |  |                                                                      
|-------------- |  | ---------------------------------------------------------------------
|Exhibit Number |  | Description                                                          
|               | 
|Exhibit 35.1   |  | Servicer Compliance Statement of AmeriCredit Financial Services, Inc.



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SIGNATURES

Pursuant to the requirements of Section 13 or 15 (d) of the Securities Exchange Act of 1934, AFS SenSub Corp. has duly caused this
report to be signed on its behalf by the undersigned, thereunto duly authorized.



| |  |     |  |                                                             |  | 
| |  | --- |  | ----------------------------------------------------------- |  | 
| |  | By: |  | AFS SENSUB CORP.,                                           |  | 
| |  |     |  | as Depositor                                                |  | 
| |  |     | 
| |  | By: |  | /s/ Chris A. Choate                                         |  | 
| |  |     |  | Name: Chris A. Choate                                       |  | 
| |  |     |  | Title: Executive Vice President and Chief Financial Officer |  | 
| |  |     |  | Dated: March 25, 2016                                       |  | 

Supplemental information to be Furnished With Reports Filed Pursuant to Section 15(d) of the Act by Registrants Which
Have Not Registered Securities Pursuant to Section 12 of the Act.

No annual report, proxy statement, form of proxy or other proxy
soliciting material has been sent to certificateholders, and the registrant does not presently contemplate sending any such materials subsequent to the filing of this report.



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EXHIBIT INDEX

AMERICREDIT AUTOMOBILE RECEIVABLES TRUST 2013-4



|               |  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
|-------------- |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|Exhibit Number |  | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
|               | 
|Exhibit 4.1    |  | Indenture, dated as of August 7, 2013, between AmeriCredit Automobile Receivables Trust 2013-4 and Wells Fargo Bank, National Association, as Trustee and Trust Collateral Agent (incorporated by reference from Exhibit 4.1 of the
Current Report on Form 8-K filed by AmeriCredit Automobile Receivables Trust 2013-4 (File No. 333-170231-13) with the SEC on August 21, 2013).                                                                                                 
|               | 
|Exhibit 4.2    |  | Amended and Restated Trust Agreement, dated as of August 7, 2013, between AFS SenSub Corp., as Seller, and Wilmington Trust Company, as Owner Trustee (incorporated by reference from Exhibit 4.2 of the Current Report on Form 8-K
filed by AmeriCredit Automobile Receivables Trust 2013-4 (File No. 333-170231-13) with the SEC on August 21, 2013).                                                                                                                            
|               | 
|Exhibit 4.3    |  | Sale and Servicing Agreement, dated as of August 7, 2013, among AmeriCredit Automobile Receivables Trust 2013-4, as Issuer, AmeriCredit Financial Services, Inc., as Servicer, AFS SenSub Corp., as Seller, and Wells Fargo Bank,
National Association, as Trust Collateral Agent (incorporated by reference from Exhibit 4.3 of the Current Report on Form 8-K filed by AmeriCredit Automobile Receivables Trust 2013-4 (File No. 333-170231-13) with the SEC on August 21,
2013).
|               | 
|Exhibit 10.1   |  | Purchase Agreement, dated as of August 7, 2013, between AmeriCredit Financial Services, Inc., as Seller and AFS SenSub Corp., as Purchaser (incorporated by reference from Exhibit 10.1 of the Current Report on Form 8-K filed by
AmeriCredit Automobile Receivables Trust 2013-4 (File No. 333-170231-13) with the SEC on August 21, 2013).                                                                                                                                      
|               | 
|Exhibit 10.2   |  | Lockbox Account Agreement, dated as of August 7, 2013, among JPMorgan Chase Bank, N.A., as Processor, AmeriCredit Financial Services, Inc., and Wells Fargo Bank, National Association, as Trustee (incorporated by reference from
Exhibit 10.2 of the Current Report on Form 8-K filed by AmeriCredit Automobile Receivables Trust 2013-4 (File No. 333-170231-13) with the SEC on August 21, 2013).                                                                              
|               | 
|Exhibit 10.3   |  | Lockbox Processing Agreement, dated as of August 7, 2013, among AmeriCredit Financial Services, Inc., Wells Fargo Bank, National Association, as Trustee, and Regulus Group II LLC, as Processor (incorporated by reference from Exhibit
10.3 of the Current Report on Form 8-K filed by AmeriCredit Automobile Receivables Trust 2013-4 (File No. 333-170231-13) with the SEC on August 21, 2013).                                                                                



---

|             |  |                                                                                                                                                                                                                  
|------------ |  | -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|             | 
|Exhibit 31.1 |  | Rule 13a-14(a)/15d-14(a) Certification (Section 302 Certification).                                                                                                                                              
|             | 
|Exhibit 33.1 |  | Managements Assertion Regarding Compliance with Applicable Servicing Criteria concerning servicing activities of AmeriCredit Financial Services, Inc. and its subsidiaries for the year ended December 31, 2015.
|             | 
|Exhibit 33.2 |  | Assessment of Compliance with Applicable Servicing Criteria (Wells Fargo Bank, National Association).                                                                                                            
|             | 
|Exhibit 34.1 |  | Report of Independent Registered Public Accounting Firm (Deloitte & Touche LLP).                                                                                                                                 
|             | 
|Exhibit 34.2 |  | Report of Independent Registered Public Accounting Firm (KPMG LLP).                                                                                                                                              
|             | 
|Exhibit 35.1 |  | Servicer Compliance Statement of AmeriCredit Financial Services, Inc.