2000 AUDI A4 APB Engine Electronic Engine Power Control Checking Workshop Manual

24-145

Throttle Valve Control Module -J338,
checking

The throttle valve control module housing
contains the following components:

CAUTION!

The housing should NOT be opened.

Throttle drive -G186 (power accelerator
actuation) (This is an electric motor activated by
the engine control module. The motor opens
the throttle valve by applying force to overcome
the spring pressure.)
Angle sensor -1- for throttle drive (power
accelerator actuation) -G187
Angle sensor -2- for throttle drive (power
accelerator actuation) -G188

Notes:
The angle sensors are in the form of
potentiometers (variable resistors). Each sends
its own separate signal to inform the engine
control module of the position of the throttle
valve (i.e. one of the signals is redundant).
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The potentiometers cannot be adjusted
mechanically. Settings are made using the
"Basic Setting" function (function 04) with
VAG1551 scan tool or VAG1552.
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24-146

Throttle valve control module,
adaptation

The adaptation process enables the Engine
Control Module (ECM) to learn the different
positions of the throttle valve with the ignition
switched on and the engine not running. These
positions are stored in the control module. The
feedback signal indicating the position of the
throttle valve comes from the two angle sensors
for throttle valve drive.
If the Throttle Valve Control Module -J338 or the
ECM is removed and installed or replaced, or if
the voltage (power) supply to the ECM is
interrupted, an adaptation must be carried out.
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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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24-148

Test conditions for adaptation of throttle
valve control module

No malfunctions stored in DTC memory
Page 01
-15
, check DTC memory

Engine not running, ignition switched on
Accelerator pedal not depressed
Coolant temperature between 5 C and
100 C (Display group 004, display field 3)

Intake air temperature less than 100 C

Voltage supply to engine control module
greater than 11Volt, Checking Page 28
-32

- Connect vehicle diagnostic, testing and
information system VAS 5051 or VAG1551 scan
tool and select engine electronics control
module by entering address word "01" Page
01
-9 . When doing this the ignition must be
switched on.
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24-149

Rapid data transfer
HELP
Select function XX

Indicated on display
- Press buttons -0- and -4- to select function "Basic Setting" and confirm
entry with -Q- button.
Basic Setting Input displa
y group number
XXX

Indicated on display
- Press buttons -0-, -6- and -0- to select "display group number 060" and
confirm entry with -Q- button.
System in Basic Setting 60
1
2
3
4

Indicated on display
- Check specification for throttle valve control module in display field 4
Page 24
-151

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24-150
When the -Q- button is pressed the throttle valve
positioner will be switched mechanically.
In this condition the throttle valve is pulled into an
"emergency running" or default position by a
mechanical spring in the throttle valve control
module. The values supplied by the two angle
sensors for this emergency running position are
stored in the Engine Control Module (ECM).
The throttle valve is then opened by a
predetermined amount. As soon as it reaches
this position the current supply to the throttle
valve positioner is again disconnected. The
spring should then close the throttle valve
mechanically to the previously learned default
position within a specified period of time (spring
test).
The throttle valve positioner then closes the
throttle valve and the values supplied by the
angle sensors in the throttle valve control module
are stored in the Engine Control Module (ECM).
If the ECM disconnects the current supply to the
throttle valve positioner while the vehicle is being
driven, the result will be an increase in idling
speed with fluctuating engine RPM (hunting) and
very slow throttle response.
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24-151

- Check specification for throttle valve control
module (display fields 4).

Display fields

1 2 3 4
Display Group 060: Adaptation of throttle valve control module with ignition on
Display xx % xx %
---
---
Indicates Throttle
valve angle
(angle
sensor 1) Throttle
valve angle
(angle
sensor 2) Learning stage counter
Adaptation status
Work
Range min.: 0 %
max.: 100
% min.: 0 %
max.: 100
% 0 to 8
ADP. runs
ADP. O.K.
ADP. ERROR
Specified
value 3 - 20 % 80 - 97 %
8
ADP. OK
Note
Learning stage counter must run from 0 to 8
during adaptation process (some digits may
also skip). If specification is not met:
Notes Page 24
-152
.
Note:

It is not important how the learning stage counter reacts during adaptation, rather the specification "ADP" is reached after
the adaptation in display field 4.
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