ECO AUDI A4 1998 B5 / 1.G APB Engine Electronic Engine Power Control Checking Workshop Manual

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If EPC warning lamp remains lit for more than 3
seconds (i.e. continuously) when ignition is on,
proceed with test as follows:

- Start engine and allow it to run at idling speed.

Specified value: EPC warning lamp should go
out.
If the EPC warning lamp does not go out:

- Check DTC memory of Engine Control Module
(ECM).
If no DTCs are stored: Cause:
EPC warning light is activated via
short circuit to Ground (GND). Corrective action:
If the specification is not reached: - Switch ignition off
- Connect VAG1598/31 test box . Do not connect engine control module.
- Measure resistance between vehicle Ground and socket 48 on test box. Specified
value: infinity (because the wire should not have any direct Ground connection)
- Determine and eliminate short circuit to Ground in wiring between engine control
module and EPC warning lamp using wiring diagram.
If there are no malfunctions in the wiring to the EPC warning lamp:
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24-147
The learning process (adaptation process) is
carried out:

By selecting "Basic Setting" (function 04),
Display Group 060 with the ignition switched
on.
Automatically if the ignition is switched on for at
least 6 seconds without operating the starter or
depressing the accelerator, and if the Engine
Control Module (ECM) registers a "learning
requirement." (In this case, however, there is no
way of knowing whether the adaptation process
was successful or not.) The engine control
module will register a learning requirement if
the previously stored voltage readings from the
angle sensors do not correspond (within a
certain tolerance range) to the new voltage
readings.

Note:
The engine will not start during automatic
adaptation.
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start again automatically the next time the
ignition is switched on (for several seconds).

-
End engine basic setting by pressing the
button.

- Press buttons -0- and -6- to select "End Output"
function and confirm input with -Q- button.
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24-156

Notes:

The reason why the value in display field 1 rises
and the value in display field 2 falls is because
the potentiometers (angle senders) in the
throttle valve control module work in opposite
directions.
The percentage value for the first potentiometer
increases as the voltage rises towards 5 V
because the voltage at this potentiometer
increases as the throttle valve opens.
The percentage value for the second
potentiometer decreases as the voltage drops
away from 5 V and towards 0 V because the
voltage at this potentiometer decreases as the
throttle valve opens.
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play?action=Goto&t
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pair&id=AUDI.B5.FU04.24.4