display AUDI A6 1997 C5 / 2.G ATW Engine Motronic Fuel Injection Syst

24-23

Engine Control Module (ECM), replacing


Special tools and equipment

or
Removing
VAS5051 with VAG5051/1VAG1551 with VAG1551/3A
- Connect VAS5051 tester or VAG1551 scan tool and select control
module for engine electronics using "address word" 01 Page 01
-10
.
Ignition must remain switched on.
4B0906018Q
1.8 L R4/5VT
G 0008
Codin
g 07551
WSC 12345

VAG1551 Scan Tool (ST) display indicates control module identification,
e.g.
- Always allow display of control module identification first and print it out
Page 01
-13
.
- Compare coding with coding versions Page 01
-64
.
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Note:

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
-16
. 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.

WARNING!

The electric fan for the radiator must not be
running. Rapid data transfer
HELP
Select function XX

When indicated on display
-
Press buttons -0- and -4- to select "Initiate basic setting" and press -Q-
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Basic Settin
g
Q
Enter 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 at 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 FWD: 740 to 860 RPM
AWD: 800 to 920 RPM FWD: 800 RPM
AWD: 860 RPM x.x % 0 0 0 0 0
Note
If specified value is not obtained
Page 24
-32

Significance of numbers
Page 24
-32
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Note:

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
-16
.
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If idle speed is too high or low and there are
no DTCs in DTC memory, the following tests
(marked with dots) must be performed:

Check for false air in intake air system
Page 24
-68
.

Check throttle valve control module Page 24
-120
.

Evaporative Emission (EVAP) canister purge
regulator valve always open, checking
Page 24
-107
.

Perform adaptation of throttle valve control
module Page 24
-121
.
Significance of 5 digit indication of display group 056 x
x
x
x
x
Display field 4
0 A/C compressor: 0 = A/C compressor off; 1 = A/C compressor on
0 Manual transmission: Indication always 0
Driving mode for automatic transmission: 0 = selector lever in P or N; 1 = selector lever in 2/3/4/D/R
0 Indication always 0
0 Indication always 0
0 Indication always 0
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Component location Overview of component
locations Page 24
-5

Test requirements:

Coolant Temperature at least 80 C.

Electrical consumers switched off (radiator
fan must NOT run during test).
A/C switched off.

Checking function

- Connect VAS5051 tester or VAG1551 scan tool
and select control module for engine electronics
using "address word" 01 Page 01
-10
. Engine
must run at idle.
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 Setting
Q
Enter displa
y group number XXX

When indicated on display
- Press buttons -0-, -0- and -2- to select "display group number 002" and
press -Q- button to confirm input. When indicated on display
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Display fields

1 2 3 4
Display group 002: Air mass taken in with engine at idle and operating temperature
Display xxx /min xxx %
xx.x ms
xxx.x g/s
Indicated Engine speed (RPM) Load
mean injection time
Air mass
Specified value FWD: 740 to 860 RPM
AWD: 800 to 920 RPM 15 to 33 %
1.0 to 4.0 ms
2.0 to 4.5 g/s
Note --- ---
If specified value is not obtained: Evaluation Page 24
-63

If specified value is obtained:

-
Press button.Rapid data transfer
HELP
Select function XX

Indicated on display (function selection):
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Evaluation display group 002 Display field:
3
Possible cause
Corrective action
less than 1.0
ms
Smaller values are only possible when driving in
deceleration mode
larger than 4.0
ms Engine under load due to power accessories.- Reduce load (A/C system/power
steering/generator)

Poor idle (does not run on all cylinders)- Check spark plugs.
- Check fuel injectors Page 24
-38
.


Throttle valve control module - J338- faulty- Check throttle valve control module
Page 24
-120

Display field:
4
Possible cause
Corrective action
smaller than
2.0 g/s
large false air mass between intake manifold and Mass Air
Flow (MAF) sensor
Voltage supply of Mass Air Flow (MAF) sensor or wire
connections to Engine Control Module (ECM) - Check intake system for leaks (false
air) Page 24
-68
.
- Check voltage supply and wire
connections Page 24
-64

larger than 4.5
g/s
Engine under load due to power accessories.- Reduce load (A/C system/power
steering/generator)

Voltage supply of Mass Air Flow (MAF) sensor or wire
connections to Engine Control Module (ECM) - Check voltage supply and wire
connections Page 24
-64

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Test sequence

- Connect VAS5051 tester or VAG1551 scan tool
and select control module for engine electronics
using "address word" 01 Page 01
-10
. Engine
must run at idle.
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 measurin
g value block
Q
Enter displa
y group number XXX

When indicated on display
- Press buttons -0-, -0- and -1- to select "display group number 001" and
press -Q- button to confirm input.
Read Measuring Value Block 1
1
2
3
4

Indicated on display(1 to 4 display fields)
If engine speed decreases: - Make note of engine speed in display field 1.
- Spray intake system parts with engine leak detection spray in a
systematic manner.
- Check sprayed part of intake system for leaks, and eliminate error.
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-
Press button.Rapid data transfer
HELP
Select function XX

Indicated on display (function selection):
- Press buttons -0- and -6- to select "End output" and press -Q- button to
confirm input.
- Switch ignition off.
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jection s
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