ELECTRICAL.
ON-BOARD DIAGNOSTICS
Misfire
A malfunction that causes a misfire during vehicle operation causes MIL to flash in equally timed increments.
This is a malfunction (e.g. misfire) that may cause catalytic converter damage. If MIL flashes in equally timed
increments during vehicle operation, cause of malfunction must be determined. See DTC IDENTIFICATION
table.
Hard Failures
Hard failures cause MIL to illuminate and remain on until problem is repaired. If MIL comes on and remains on
during vehicle operation, cause of malfunction must be determined. See DTC IDENTIFICATION table. In
addition EPC malfunctions are indicated by an EPC warning light and MIL in instrument cluster. See Fig. 2 and
Fig. 3 under MALFUNCTION INDICATOR LIGHT (K83) . For most sensors, if a sensor fails, ECM will
use a substitute value in its calculations to continue engine operation. In this condition, commonly known as
limp-in or limp-home mode, the vehicle runs but driveability will not be optimum.
The Engine Speed (RPM) sensor (G28) is a speed and reference mark sensor. The engine will not start if there
is no engine speed (RPM) signal. If the engine speed (RPM) signal fails when the engine is running, it will
cause the engine to stall immediately.
Sporadic Malfunctions (Intermittent Failures)
Sporadic malfunctions (intermittent failures) may cause Malfunction Indicator Light (MIL) to flicker or
illuminate and go out after the intermittent fault goes away. DTC will be retained in ECM memory. Sporadic
malfunctions (intermittent failures) may be caused by a sensor, connector or wiring related problems.
MALFUNCTION INDICATOR LIGHT (K83)
CAUTION: A Malfunction Indicator Light (MIL) flashing in equally timed increments
during vehicle operation indicates malfunction(s) causing a misfire.
Vehicle must not be driven at full power and must be diagnosed and
repaired before catalytic converter damage occurs.
NOTE:
When using Scan Tool VAG 1551/1552 or VAS 5051/5052, malfunctions which
only occur sporadically (intermittently) will have the addendum sporadic
(intermittent) malfunction on the print out and will be indicated on the display
by the addendum /SP. Cause of sporadic malfunctions can be e.g. a loose
contact or a intermittently open circuit. If a sporadic malfunction does not occur
again within 40 warm-up phases, sporadic DTC(s) will be erased from ECM
memory. A warm-up phase is, engine started with coolant temperature below
122°F (50°C), switched off at above 162°F (72°C).
2003 Volkswagen New Beetle GLS
2001-2003 ENGINE PERFORMANCE Self-Diagnostics - 2.0L - Beetle, Golf & Jetta (Engine Codes AVH & AZG)
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