Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Audi >> 2002 >> S4 Quattro, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics - 2.7L Turbo >> Self-Diagnostic System >> Function 02 - Retrieving Diagnostic Trouble Codes

Function 02 - Retrieving Diagnostic Trouble Codes

NOTE: Ensure battery voltage is 12.7 volts or more. Ground connections at engine and transmission are okay. For circuit identification, see 2002, see WIRING DIAGRAMS article.
NOTE: While limited diagnostic information is available, vehicle manufacturer does not support diagnostic information using aftermarket scan tools. To properly diagnose vehicle, it is recommended to use VAS 5051 scan tool with VAS 5051/1 adapter cable or VAG 1551 scan tool with 1551/3A adapter cable and VAG 1598/31 test box.

DTCs can be retrieved using either 00 - AUTOMATIC TEST SEQUENCE (guided fault finding) or 01 - ENGINE ELECTRONICS. Using address word 00 - AUTOMATIC TEST SEQUENCE results in a DTC check of all OBD capable systems in the vehicle via rapid data transfer mode. Using address word 01 - ENGINE ELECTRONICS will result in only Engine Control Module (ECM) DTCs being retrieved. To retrieve DTCs using address word 00 - AUTOMATIC TEST SEQUENCE, see ADDRESS WORD 00 - AUTOMATIC TEST SEQUENCE (GUIDED FAULT FINDING)  under ADDRESS WORDS & DIAGNOSTIC FUNCTIONS.

To retrieve DTCs using address word 01 - ENGINE ELECTRONICS, perform following steps:

  1. Connect VAS 5051 or generic scan tool to Data Link Connector (DLC). DLC is located behind cover under left side of steering column. See Fig 1. Turn ignition on or start engine and let it idle. On scan tool, from RAPID DATA TRANSFER, press "02" to select diagnostic function 02 - CHECK DTC MEMORY. Press "Q" button to confirm input, and go to next step.
    Fig 1: Locating Data Link Connector
    G97F07184Courtesy of AUDI OF AMERICA, INC.
  2. Observe scan tool display field 1 to select DTC memory content. If "0" is displayed, no malfunctions exist. If "X" is displayed, malfunctions have been recognized. Observe display field 2 for malfunction location and type. If malfunctions were recognized, go to next step. If no malfunctions were recognized, go to step  5.
  3. If VAS 5051 scan tool is being used, print out screen content, or OBD protocol. Press "BACK ARROW" button to end function 02 - CHECK DTC MEMORY. If any DTCs are displayed, perform appropriate test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If there are no DTCs in DTC memory, DTC memory should not be unnecessarily erased otherwise readiness code will be lost and must then be regenerated. If DTC memory was erased, readiness code must be re-generated. Go to next step.
  4. After making necessary repairs, on scan tool press "05" to select diagnostic function 05 - CLEARING DTC MEMORY. Press "Q" button to confirm entry, and erase DTC memory. After DTC memory is erased, readiness code must be re-generated See READINESS CODE .
  5. On scan tool, on scan tool press "06" to select diagnostic function 06 - END OUTPUT. Press "Q" button to confirm entry. Turn ignition off, and disconnect scan tool from DLC.

scientia non olet · About Mike's Workshop Manuals