OBD II, Generic Mode Operation

Introduction To OBD II, Generic Mode Operation

The information under "On Board Diagnostic II With Generic Scan Tool" for the 2.0 Liter OBD II fuel injection and ignition system covers "generic" scan tool diagnosis and repair with ANY available OBD II scan tool, using Address Word 33.

Starting with my. 1996, U.S. government regulations require 2nd generation On Board Diagnostic (OBD II) systems on vehicles sold in the United States, with Diagnostic Trouble Code (DTC) memory that is accessible to technicians without using the manufacturer's proprietary scan tool, such as VAG 1551.

For specific emissions-related malfunctions, the engine management system must generate and store a specific description of each malfunction (identified by a standard "P" code) in the Engine Control Module (ECM).

P-codes and descriptions can be retrieved using ANY available OBD II scan tool, including the Volkswagen VAG 1551 Scan Tool operating in "generic" mode. This information can then be used in conjunction with additional repair and testing recommendations find also under "On Board Diagnostic II With Generic Scan Tool" to troubleshoot and repair emissions-related malfunctions.

This scan tool described here is the Volkswagen/Audi VAG 1551 Scan Tool operating in "generic" mode. For the workshop equipped with VAG 1551, this booklet offers alternatives for system diagnosis and repair, emphasizing on-vehicle troubleshooting rather than the full range of VAG 1551 Scan Tool Output Diagnostic Test Mode (DTM) and Measuring Value Block functions.