check engine AUDI A6 1995 C5 / 2.G ATQ Engine Motronic Injection System Servicing Workshop Manual
[x] Cancel search | Manufacturer: AUDI, Model Year: 1995, Model line: A6, Model: AUDI A6 1995 C5 / 2.GPages: 78, PDF Size: 1 MB
Page 3 of 78

24-2
      
It is possible that the control module will 
recognize a malfunction and store a DTC during 
some tests. After completing all tests and 
repairs, DTC memory should therefore be 
checked and erased if necessary. Readiness 
code must be generated after DTC memory is 
erased  Page 01
-82
 . 
     
Always switch ignition off before cleaning 
engine. 
     The battery should only be disconnected and 
reconnected when the ignition is turned off, 
since otherwise the Engine Control Module 
(ECM) can be damaged. 
     
WARNING! 
     
Fuel system is under pressure! Place a cloth 
around the connection point before opening 
system. Then release pressure by carefully 
loosening connection point. 
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Page 10 of 78

24-8
 
  
10 - 
E-box in plenum chamber 
Motronic Engine Control Module (ECM) -
J220- Secondary Air Injection (AIR) Pump Relay -
J299-  Fig.  10
 , page   Page 24
-12
 
11 - 
Valve -2- for camshaft adjustment -N208- 
12 - 
Camshaft Position (CMP) sensor 2 -G163- 
Bank 1
13 - 
Heated Oxygen Sensor (HO2S) -G39- 
before catalytic converter with Oxygen 
Sensor (O2S) Heater -Z19- Bank 1, sensor 1
14 - 
Ground connection on the engine bracket, right side
15 - 
Mass Air Flow (MAF) sensor -G70- Checking  Page 24
-56
16 - 
Evaporative Emission (EVAP) canister 
purge regulator valve -N80- 
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Page 11 of 78

24-9
 
  
17 - 
Engine Coolant Temperature (ECT) sensor 
-G62- 
for Engine Control Module (ECM)At coolant line behind cylinder head engine 
bank 1 with Engine Coolant Temperature (ECT) 
Sensor -G2- Checking  Page 28
-23
If necessary, release pressure in cooling 
system before removing 
18 - 
Throttle valve control module -J338- With throttle drive (power accelerator 
actuation) -G186-, angle sensor -1- for 
throttle drive (power accelerator actuation) 
-G187-, and angle sensor -2- for throttle 
drive (power accelerator actuation) -G188- 
19 - 
Intake Manifold Change-Over Valve -N156-
20 - 
Fuel pressure regulator 
21 - 
Engine Speed (RPM) sensor -G28- in transmission housing via ring gearChecking  Page 28
-19
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Page 22 of 78

24-20
 
    
Important note:  
After re-connecting the Engine Control Module (ECM), the following work 
steps must be performed: 
- Check DTC memory and erase it if necessary   Page 01
-15
 . 
- Perform adaptation of the Throttle Valve Control Module -J338-   Page 
24
-142
 . 
Note:  
In the first adaptation phase during engine basic setting, it is possible that 
idle will be rough and vehicle may shake lightly in drive mode.  -  Connect VAG1598/31 test box to connector of wiring harness. Ground 
(GND) clip at test box (not visible in illustration) must be connected to 
Ground (GND). Relevant test procedures note whether Engine Control 
Module (ECM) should also be connected to the test box. 
-  Perform test as described in relevant repair sequence.
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Page 25 of 78

24-23
 
    
Installing  
Installation is reverse of removal, noting the following:  
Important note:  
After installing new Engine Control Module (ECM), the following work 
steps must be performed: 
- Check DTC memory and erase it if necessary   Page 01
-15
 . 
- Perform adaptation of the Throttle Valve Control Module -J338-   Page 
24
-142
 .  -  Using a screwdriver, carefully pry off retaining bracket (arrow).
-  Disengage locking lugs and remove control module connector.
-  Remove Engine Control Module (ECM).
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Page 26 of 78

24-24
      - Observe notes for coding new Engine Control 
Module (ECM)   Page 01
-71
 . 
     - For vehicles with cruise control (discernable at 
steering column), switch this free in ECM: 
     
       Repair Manual, Electrical Equipment, Repair 
Group 01; On Board Diagnostic (OBD) of cruise control system; Cruise control system, checking
   
     - Adapt immobilizer to Engine Control Module 
(ECM): 
     
       Repair Manual, Electrical Equipment, Repair 
Group 01; On Board Diagnostic (OBD) of immobilizer after replacing Engine Control Module (ECM)
   
     - For vehicles with automatic transmission, the 
kick down function must be learned   Page 24
-
161
 . 
     - Generate readiness code   Page 01
-82
 . 
     
Note:  
     In the first adaptation phase during engine basic 
setting, it is possible that idle will be rough and 
vehicle may shake lightly in drive mode. 
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Page 28 of 78

24-26
      
Notes:  
     
Idle speed cannot be adjusted.
     Idle speed is checked during basic setting of 
the engine. 
     During basic setting, the Evaporative Emission 
(EVAP) canister purge regulator valve (EVAP 
valve -N80-) is closed and the A/C compressor 
is switched off 
     
Test sequence  
     
-  Check DTC Memory   Page 01
-15
. There must 
not be any DTCs stored, repair malfunctions if 
necessary, erase DTC memory, switch engine 
off and start again, road test vehicle and check 
DTC memory again as a control measure. 
     
-  Let engine continue to run at idle.
     
CAUTION! 
     
The electric cooling fan must not run. 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. 
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Page 29 of 78

24-27
 
Basic Settin
g 
Q
Input display group number XXX
    
When indicated on display:  
-  Press buttons -0-, -5- and -6- to select "display group number 056" and press -Q-
button to confirm input. 
System in Basic Setting 56  
1 
2 
3 
4 
    
When indicated on display:  
-  Check whether the engine speed in display field 1 (actual engine speed) is within 
tolerated range. 
  
Display fields  
  
1   2   3   4  
Display group 056: Idle stabilization with engine at idle and operating temperature  
Display  
xxx /min  
xxx /min   x.x %   X X X X X  
Indicated  
Engine speed (actual)  
Engine speed 
(specified)  Idle control  
Torque 
change  Operating conditions  
Specified 
value  720 to 820 RPM 
1)  
630 to 730 RPM 2)  770 RPM 
1)  
680 RPM 2)  -5 to 5 %   0 0 0 0 0  
Notes  
If specified value is not obtained   
Page 24
-29
   
    Significance of 
numbers 
 Page 24
-29
   
1) Front Wheel Drive Vehicles  
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Page 31 of 78

24-28
      
Notes:  
     
Engine speed in display field 1 (actual engine 
speed) is the current engine speed. 
     Engine speed in display field 2 (specified 
engine speed) is a theoretical engine speed 
calculated by the ECM. 
     At idle, the ECM always attempts to adapt the 
engine speed (actual) to the specified engine 
speed (specified). 
     This means that the engine speed (actual) must 
always approximately match the engine speed 
(specified) at idle. 
     Display fields 3 and 4 provide information, but 
are not relevant for checking idle speed. 
      If specified value is obtained:  
     
- 
Press button.
Rapid data transfer 
HELP
Select function XX
    
Indicated on display (function selection):  
If specified value is not obtained:  
-  Check DTC memory again   Page 01
-15
 .
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Page 35 of 78

24-30
      
Fuel pressure regulator and residual 
pressure, checking
 
     
Note:  
     Fuel pressure regulator regulates fuel pressure 
according to intake manifold pressure. This 
ensures that the pressure drop at the fuel 
injectors remains the same for each speed and 
load range of the engine. 
     
Special Tools and Equipment  
    
Test requirements: 
 Repair Manual, Fuel Supply System, Repair Group 20; Fuel supply Front Wheel Drive or fuel supply 
- All Wheel Drive
   
VAG 1318 with VAG 1318/7 adapter, VAG 1318/8 pressure hose with 
connectors and VAG 1318/15 adapter Fuel Pump (FP) OK, checking   Page 24
-49
 . 
Fuel Pump (FP) OK, checking: Fuel filter OK Battery voltage at least 12.7 V Vehicles with automatic transmission Selector lever in P or N. 
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