On Board Diagnostic II, Features

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2001 Volkswagen Jetta, 2001 Volkswagen Golf, 2000 Volkswagen Jetta, 2000 Volkswagen Golf, and 1999 Volkswagen Jetta. However, it is still accessible from the selected car via links, so may be relevant.

The Engine Control Module J248 (ECM) for the diesel direct fuel injection (DFI) system is equipped with a Diagnostic Trouble Code (DTC) memory.
If malfunctions occur in the sensors and components being monitored, they will be stored in DTC memory together with an indication of the malfunction type.
After evaluating the information, the ECM decides between 85 different malfunctions → Diagnostic Trouble Code (DTC) table → DTC table: V.A.G codes or → Diagnostic Trouble Code (DTC) table: SAE P codes and stores them until the DTC memory is erased.
Malfunctions which only occur sporadically will have the addendum "sporadic" on the print out. These malfunctions will be indicated on the display by the addendum "/SP". The cause of sporadic malfunctions can be e.g. a loose terminal or a brief open circuit. If a sporadic malfunction does not occur again within 40 warm-up cycles, it will be erased from DTC memory.

The warm-up cycle is designated by each engine start, beginning at an Engine Coolant Temperature below 49 ° C (120 ° F) and runs continuously until the temperature reaches 71 ° C (160 ° F).

Malfunctions can be read with Scan Tool (ST) V.A.G 1551 , V.A.G 1552 or VAS 5051 → Diagnostic Trouble Code (DTC) memory, checking and erasing .

Fig 1: Malfunction Indicator Lamp & Glow Plug Indicator Lamp

Courtesy of VOLKSWAGEN UNITED STATES, INC.

If malfunctions that influence exhaust emissions are recognized, Malfunction Indicator Lamp K83 (MIL) - 1 - illuminates.

If malfunctions are recognized that affect driveability, the glow plug indicator lamp - 2 - blinks.

DTC memory must be erased after malfunctions have been eliminated → Diagnostic Trouble Code (DTC) memory, checking and erasing

After erasing DTC memory, set the readiness code again → Readiness code, setting .

NOTE:

On Board Diagnosis (OBD) information can be found in V.A.G 1551 Scan Tool (ST) instruction manuals, vehicle system tester V.A.G 1552 or the new VAS 5051 ST.