AUDI A4 1998 B5 / 1.G AFC Engine On Board Diagnostic Multiport Fuel Injection Workshop Manual

01-166
Test table display group 001 Display
field Display on
VAG 1551 scan
tool Malfunction cause
Malfunction repair
1 Greater than
110
or
Less than 85
Engine Coolant Temperature (ECT)
sensor -G62-
Wiring connection to Engine Control
Module (ECM) -J192-
Coolant thermostat faulty
Repair Manual, 2.8 Liter V6 2V Engine
Mechanical, Engine Code(s): AFC, Repair Group 19
- Check DTC memory page 01
-13
- Check -G62- page 28
-25
- Check engine coolant thermostat
2 Less than 1.450
V
Large intake air leak between intake
manifold and Mass Air Flow (MAF)
sensor Repair cause
Greater than
1.580 V Electrical consumers on, steering wheel
at end stop, driving mode selected
(automatic transmission)
Tolerance for new engines: - Switch consumers off
- Center steering wheel
- Put selector lever in P or N position
display group 004, display field 4
Max. 1.660 V
When engine speed increases, the display
value increases to 2.500 V, falls to 0.000 V
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and starts to go up again
4 Greater than
14.000 V
or
Less than
12.000 V
Generator faulty
Overvoltage because of starting aid
Poor ground connection to ECM -J192-
Discharged battery
Current draw with ignition off - Check voltage
- Check battery charging status
- Check voltage supply of Engine Control
Module (ECM) Repair Group 28
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01-167
Notes on display field 1:

The Engine Coolant Temperature (ECT) sensor is a temperature-dependent resistor. If the sensor signal is falsified by e.g.
dampness in the harness connection (effect as with resistors connected in parallel), this falsification can lie in a range that
is not recognized by the DTC memory.
If a malfunction relating to the Engine Coolant Temperature (ECT) sensor is stored, a coolant temperature of 20 C (68
F) is displayed in the measuring block at engine start. 10 C (50 F) is added to this for each minute of engine operation.
The maximum replacement value is 85 C (185 F).
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01-168
Display group 002 Display shows
Display/specified value
Designation
Basic setting 2
1 2 3 4 0.250 - 4.750 V 1 = Throttle position sensor voltage (idle to full throttle range)
0.250 - 1.275 V 2 = Throttle position sensor voltage (idle and lower partial throttle range)
0.250 - 0.500 V 3 = Learning value of Throttle position sensor
0 or 1 4 = Mechanical Closed Throttle Position (CTP) switch:
0 = open 1 = closed Test table display group 002 Display
field Display on VAG
1551 scan tool Malfunction cause
Malfunction repair
1 Deviation from
tolerance range
Throttle position sensor -G69-
incorrectly adjusted or faulty - Check DTC memory page 01
-13
- Check and adjust -G69- page 24
-77

and/or display group 009, display field 4
2 Outside tolerance
range
Throttle position sensor -G69-
incorrectly adjusted or faulty - Check DTC memory page 01
-13
- Check and adjust -G69- page 24
-77

and/or display group 009, display field 4
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01-169

Display
field Display on VAG
1551 scan tool Malfunction cause
Malfunction repair
3 Outside tolerance
range
Closed Throttle Position (CTP)
switch activated or faulty CTP switch or throttle position
sensor -G69- incorrectly adjusted Electrical consumers onSteering wheel at end stopDriving mode selected (automatic
transmission) Moisture in connector for -G69-Ground point on intake manifold - Check DTC memory page 01
-13
- Check and adjust -G69- page 24
-77
- Switch electrical consumers off
- Center steering wheel
- Selector lever in P or N display group 004,
display field 4 - Visual inspection
- Check ground connection according to wiring
diagram
4 0 or 1
Closed Throttle Position (CTP)
switch -F60- faulty Throttle position sensor -G69-
incorrectly adjusted Throttle sticks Floor mat presses against
accelerator pedal Moisture in connector of -G69-Accelerator pedal cable adjustment Display group 011, display field 4
Repair Manual, 2.8 Liter V6 2V Engine
Mechanical, Engine Code(s): AFC, Repair Group 20
- Check DTC memory page 01
-13
- Check and adjust -F60- page 24
-73
- Visual inspection
- Adjust accelerator pedal cable:
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Notes on display field 3:

The mechanical Closed Throttle Position (CTP) switch must be closed for the testing on the Throttle position sensor
learning values display field 4. If the displays in display fields 2 and 3 match at idle, the learning process is OK. If no learning process takes place, the
last value learned will be displayed continuously.
If engine control module is without power, the throttle position sensor learning value will be set to 0.550 V.
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01-170
Display group 003 Display shows
Display/specified value
Designation
Basic setting 3
1 2 3 4 650 - 750 RPM 1 = Momentary idle speed
15.0 - 35.0% 2 = Engine load idle1)
0% and/or greater than 95% 3 = Throttle angle - at idle: 0%; at wide open throttle: > 95%
... km/h 4 = Momentary vehicle speed 1) Evaluate engine load tolerance range only at idle during "Basic Setting" function 04.
Note on display field 1:
Idle speed on vehicles without A/C and rear windshield heater switched on: 750-850 RPM.
Notes on display field 3:
For the testing at wide open throttle, stop engine, and switch ignition on.
Since in vehicles with manual transmission and automatic transmission different throttle bodies are installed, the start of
opening of the throttle body can be measured with ignition on and thus incorrect installation can be checked
Manual transmission: 45-53%
Automatic transmission: 27-35%
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01-171
Test table display group 003 Display
field Display on VAG
1551 scan tool Malfunction cause
Malfunction repair
1 Greater than 750
RPM
Closed Throttle Position (CTP)
switch -F60- Large air leak quantity Idle Air Control (IAC) valve -N71-
sticks or is hard to move Rear windshield heater on Display group 04, display field 4
- Check -F60- page 24
-73
- Repair cause
- Check using output diagnostic test mode
page 01
-145

- Switch electrical consumers off
Less than 650 RPM
Idle Air Control (IAC) valve -N71-
sticks or is hard to move Closed Throttle Position (CTP)
switch -F60- Driving mode selected (automatic
transmission) Display group 004, display field 4
- Check using output diagnostic test mode
page 01
-145

- Check -F60- page 24
-73
- Move selector lever to P or N
2 Outside tolerance
range
Poor idle (not running on all
cylinders) Mass Air Flow (MAF) sensor -G70-
faulty Idle Air Control (IAC) valve -N71-
faulty Electrical consumers on- Fuel injectors or spark plugs faulty
- Check DTC memory page 01
-13
and/or
display group 001, display field 2 and 3
- Check DTC memory page 01
-13
and/or
display group 018
- Switch electrical consumers off
- Center steering wheel
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Steering wheel at end stopDriving mode selected (automatic
transmission) - Move selector lever to P or N
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01-172

Display
field Display on VAG
1551 scan tool Malfunction cause
Malfunction repair
3 Greater than 0%
at idle
Throttle position sensor -G69- faultyAccelerator pedal cable adjustmentThrottle sticks
Repair Manual, 2.8 Liter V6 2V Engine
Mechanical, Engine Code(s): AFC, Repair Group 20
- Check DTC memory page 01
-13
and/or
display group 002
- Adjust accelerator pedal cable:- Repair cause
At wide open
throttle less than
95%
Throttle position sensor -G69- faultyAccelerator pedal cable adjustment Throttle position sensor -G69- incorrectly
adjusted
Repair Manual, 2.8 Liter V6 2V Engine
Mechanical, Engine Code(s): AFC, Repair Group 20
- Check DTC memory page 01
-13
and/or
display group 002
- Adjust accelerator pedal cable:- Check and adjust sensor -G69- Repair
Group 24
4 No display
Wiring connection between instrument
panel insert and Engine Control Module
(ECM) -J192- faulty Open circuit or short between Vehicle
Speed Sensor (VSS) -G68- and -J192- - Electrical Wiring Diagrams, - Check vehicle speed signal page 24
-97
- Check -G68- check vehicle speed
sensor:
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