sensor AUDI A4 1995 B5 / 1.G ATQ Engine Electronic Engine Power Control Checking Workshop Manual
[x] Cancel search | Manufacturer: AUDI, Model Year: 1995, Model line: A4, Model: AUDI A4 1995 B5 / 1.GPages: 41, PDF Size: 0.21 MB
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24-134
 
     
Electronic engine power 
control (E-Gas), checking 
     
E-Gas system, function
 
      For E-Gas, the throttle valve is not operated by a 
cable from the accelerator pedal. There is no 
mechanical connection between the accelerator 
pedal and the throttle valve.  
      The position of the accelerator pedal is 
communicated to the Engine Control Module 
(ECM) via two sensors for accelerator pedal 
position (variable resistances; stored in one 
housing) that are connected with the accelerator 
pedal.  
      The accelerator pedal position (driver's intention) 
is a main input unit for the ECM.  
      Operation of the throttle valve occurs via an 
electric motor (throttle valve actuator) in the 
throttle valve control module. This is true across 
the entire engine speed and engine load 
spectrum.  
      The throttle valve is operated by the throttle valve 
actuator according to the instructions of the 
ECM.  
      With ignition switched on and engine off, the 
ECM activates the throttle valve actuator 
precisely according to the sensor for accelerator 
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24-135
       With engine running (under load), the ECM can 
open or close the throttle valve independently of 
the sensor for accelerator pedal position.  
      This means, for example, that the throttle valve 
could be fully opened even though the 
accelerator pedal has only been depressed half 
way. This has the advantage of preventing 
torque losses at the throttle valve.  
      In addition to this, it results in significantly better 
values relative to emissions and consumption 
under certain load conditions.  
      It would be incorrect to think that "E-Gas" 
consists of only one or two component. E-Gas is 
much more of a system containing all 
components that contribute to recognizing, 
controlling and monitoring the position of the 
throttle valve, e.g. sensor for accelerator pedal 
position, throttle valve control module, EPC 
warning lamp, Engine Control Module (ECM).  
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Page 11 of 41

24-141
      
Throttle valve control module -J338-, 
checking
 
      The following components are located in the 
housing for the throttle valve control module:  
     
Throttle drive (power accelerator actuation) -
G186-. (This is an electric motor that is 
activated by the ECM. This electric motor opens 
the throttle valve against spring pressure.) 
     Angle sensor -1- for throttle drive (power 
accelerator actuation) -G187- 
     Angle sensor -2- for throttle drive (power 
accelerator actuation) -G188- 
     
Notes:  
     The housing for the throttle valve control 
module must not be opened. 
     The angle sensors are designed as 
potentiometers (variable resistances). They 
communicate the position of the throttle valve to 
the Engine Control Module (ECM) fully 
independent of each other. 
     The potentiometers cannot be mechanically 
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24-142
      
Throttle valve control module, adapting
 
      The adaptation teaches the Engine Control 
Module (ECM) various positions of the throttle 
valve when the ignition is on and the engine is 
stopped. These positions are stored in the 
control module The return communication 
regarding the position of the throttle valve occurs 
via the two angle sensors for throttle drive.  
      An adaptation must always be performed when 
the throttle valve control module -J338- or the 
Engine Control Module (ECM) are removed and 
installed (or replaced) or if voltage supply to the 
Engine Control Module (ECM) is interrupted.  
      The learning process (adaptation) occurs:  
     
automatically if the ignition is switched on for at 
least 10 seconds without operating starter and 
accelerator pedal and the Engine Control 
Module (ECM) recognizes "adaptation 
required". (There will be no notification of 
whether adaptation was successful or not 
however). Adaptation required is recognized if 
stored voltage values from the angle sensors 
do not match actual measured voltage values 
within a certain tolerance range. 
     via initiation of basic setting (function 04) 
display group 060 with ignition on. 
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24-144
      
Procedure  
     
-  Connect VAS5051 tester or VAG1551 scan tool 
and select the control module for engine 
electronics using "address word" 01   Page 01
-
9 . 
     
   Ignition must remain switched on for this.Rapid data transfer  
HELP
Select function XX
    
When indicated on display:  
-  Press buttons -0- and -4- to select "Initiate basic setting" and press -Q- 
button to confirm input. 
Basic Settin
g 
Q
Input display group number XXX
    
When indicated on display:  
After pressing Q-button, throttle valve actuator will be switched on without 
current.  
In this condition, the throttle valve will be drawn into an emergency 
position by a mechanical spring, which is located in the throttle valve 
control module. The values supplied by the two angle sensors in this 
emergency position are stored by the Engine Control Module (ECM).  -  Press buttons -0-, -6- and -0- to select "display group number 060" and 
press -Q- button to confirm input. 
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24-145
       Next, the throttle valve is opened by a certain 
value. If this value is reached, the throttle valve 
actuator is once again de-energized. Now, the 
mechanical spring must close the throttle valve to 
the previously learned emergency position within 
a specified time (spring test).  
      Then, the throttle valve is closed by the throttle 
valve actuator; the values supplied by the angle 
sensors in the throttle valve control unit are 
stored by the Engine Control Module (ECM).  
      If Engine Control Module (ECM) should de-
energize throttle valve actuator during driving 
operation, this is expressed by an increased, 
surging idle speed (RPM). The engine accepts 
gas only after great delay.  System in Basic Setting 60  
1 
2 
3 
4
    
When indicated on display:  
-  Check specified values for throttle valve control module in display fields 
3 and 4. 
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24-146
 
  
Display fields  
  
1   2   3   4  
Display group 060: Adaptation of throttle valve control module  
Display   xx %   xx %  
x  
---  
Indicated  Throttle 
valve angle  
(angle 
sensor 1)  Throttle 
valve angle  
(angle 
sensor 2)  Adaptation step counter  
Adaptation condition  
Functional 
range  0 to 100%   0 to 100 %  
0 to 8  
ADP in progress  
ADP OK  
ADP ERROR  
Specified 
value  3 to 93 %   97 to 3 %  
8  
ADP OK  
Notes  
  
  
After adaptation, the adaptation step 
counter reaches the number 8 (it is OK for 
numbers to be skipped).  If "ADP ERROR." is displayed: 
Check DTC memory   Page 
01
-15
 .  
If specified value is not 
obtained: Note, page  
Page 24
-147
 .  
Note for display field 3:  
Different numbers are shown in display field 3 during adaptation that represent the current adaptation condition. It is not 
particularly important how the adaptation step counter (display field 3) behaves during adaptation, but rather that display field 
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Page 21 of 41

24-148
 
  
Angle sensor -1- for throttle drive, 
checking
 
Special Tools and Equipment  
 
VAG1526A
 VAG1594A
 VAG1598/31
 VAS5051 with VAG5051/1
- or 
 VAG1551 with VAG1551/3B
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24-149
       Angle sensor 1 for throttle drive (power 
accelerator actuation) -G187- and angle sensor 1 
for throttle drive (power accelerator actuation) -
G188- inform the Engine Control Module (ECM) 
about the position of the throttle valve. Both 
angle sensors are located in the throttle valve 
control module.  
     
Test sequence  
     
-  Connect VAS5051 tester or VAG1551 scan tool 
and select the control module for engine 
electronics using "address word" 01   Page 01
-
9 . 
     
   Ignition must remain switched on for this.Rapid data transfer  
HELP
Select function XX
    
When indicated on display:  
-  Press buttons -0- and -8- to select "Read Measuring Value Block" and 
press -Q- button to confirm input. 
Read Measuring Value Block 
Q
Input displa
y group number XXX
    
When indicated on display:  
-  Press buttons -0-, -6- and -2- to select "display group number 062" and 
press -Q- button to confirm input. 
Read Measuring Value Block 62  
1 
2 
3 
4
    
Indicated on display:  
-  Check specified values for E-gas potentiometer voltages in display 
fields 1 and 2. 
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Page 23 of 41

24-150
 
  
Display fields  
  
1   2   3   4  
Display group 062: E-Gas potentiometer voltages  
Display  
xx %  
xx %   xx %   xx %  
Indicated  
Throttle valve angle  
(angle sensor 1)  Throttle valve angle  
(angle sensor 2)  Sensor for  
Pedal position  Sensor 2 for  
Pedal position  
Specified value  
3 to 93 %  
(Idle value: 
8 to 18 %)  97 to 3 %  
(Idle value: 
80 to 90 %)  12 to 97 %   4 to 49 %  
Specified value  
3 to 93 %  
97 to 3 %   12 to 97 %   4 to 49 %       
Note:  
     Engine Control Module (ECM) calculates the 
voltage values of the angle sensors in percent 
relative to 5 volts and displays these percentage 
values. (5 volts supply voltage represents 100 
%). 
     
-  Observe display field 1 and 2.
     
-  Slowly depress accelerator pedal completely.
      Percent indication in display field 1 must rise 
uniformly. The tolerance range of 3 to 93% will 
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