stop start AUDI A4 1995 B5 / 1.G AFC Engine On Board Diagnostic Multiport Fuel Injection Workshop Manual

01-6

The MFI control module differentiates among approx. 150 different malfunctions after evaluating the information, and
stores them until the DTC memory is erased Diagnostic Trouble Code (DTC) table, page 01
-26
.
If possible, the DTC memory should be checked with engine running.
If no malfunction is stored in the DTC memory, do not additionally erase DTC memory with function 05 since the readiness
code (if it has been set) will be erased.
The DTC memory should only be erased with function 05 since the DTC memory is erased immediately with mode 4 even
if the DTC memory was not checked before that.
If a malfunction recognized by the On Board Diagnostic (OBD) is eliminated, the following work steps should be carried
out after that:
- Erase DTC memory
- Stop engine (switch ignition off) and start it again
- Take a test drive
- Carry out automatic test sequence by inserting address word 00 Note:
Every time the DTC memory is erased (both with function 05 and with mode 4), the readiness code is reset.
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01-15

Rapid data transfer DTC Memor
y is erased

Indicated on display
-
Press button.
Rapid data transfer
HELP
Select function XX

Indicated on display
Note:
After address word 00 is inserted, the DTC memory of all systems with
rapid data transfer is checked. - Repair malfunctions printed out according to Diagnostic Trouble Code
(DTC) table page 01
-26
.
- After repairing the malfunctions, check DTC memory again to erase
any malfunctions that may have been stored (e.g. by disconnecting
connectors).
- Stop engine (switch ignition off) and start again.
- Test drive for at least 10 minutes.
- Carry out Automatic Test Sequence by inserting address word 00.
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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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If the EGR flow test is to be carried out selectively or after an OK diagnosis, stop the engine and start it again.
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01-234

Display
shows Display specified
value Designation/diagnosis
Basic setting
42
1 2 3 4 400 - 640 C
1 = Calculated exhaust gas temperature in front of three way catalytic converter
(calculated value inside control module)
X X X X X X X X 2 = Diagnosis status and/or result
X X X X X X X X 3 = Diagnostic conditions 1 for heated oxygen sensor diagnosis (response time of
heated oxygen sensor)
X X X X X X X X 4 = Diagnostic conditions 2 for heated oxygen sensor diagnosis (response time of
heated oxygen sensor)
Note on display field 2:
If after diagnosis all 8 displays are "1" and the engine is stopped and started again, display values 1 and 2 are reset to "0" and
values 3 to 8 remain at "1." If during the trip diagnostic conditions (display fields 3 and 4) are achieved, display values 1 and 2
are set to "1" (diagnosis active) and display values 3 to 8 are set to"0".
Value "0": Diagnosis not active and/or diagnosis not finished and/or diagnosis result not OK
Value "1": Diagnosis active and/or diagnosis finished (whether OK or not OK) and/or diagnosis result OK X
X
X
X
X
X
X
X
Meaning of 8-digit "Diagnosis status and/or result"

1 = Diagnosis, bank 1 active

2 = Diagnosis, bank 2 active

3 = Diagnosis, bank 1 finished

4 = Diagnosis result, bank 1, flank fall time
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01-239

The diagnostic conditions are only achieved during a trip of approx. 1-1/2 to 5 minutes at 80-100 km/h (50-63 mph) with
manual transmission in 4th or 5th gear, or automatic transmission selector lever in "D" position, preferably in 4th gear.
However, the diagnostic conditions are only displayed 4 minutes after engine start, because until that time diagnosis is
prohibited. If the diagnostic conditions are fulfilled, diagnosis is active. Now, obtaining a diagnostic result requires a test
drive of approx. 1-1/2 to 5 min under the diagnostic conditions.
If a malfunction is stored in DTC memory that affects diagnostic conditions 1 and 2, the diagnostic conditions can not be
obtained. In this case repair the malfunction "DTC memory, checking and erasing," page 01
-13
. If a malfunction is
stored that involves the heated oxygen sensors in front of three way catalytic converter, the diagnostic conditions can be
achieved, but the diagnosis result can not be OK.
If the effect of the three way catalytic converter is recognized as OK during the first diagnosis, the diagnosis is
discontinued. If the effect (conversion) is recognized as not OK, the three way catalytic converter diagnosis is continued. If
the diagnosis will be repeated selectively and/or repeated after an OK diagnosis, stop the engine and start again.
Display
shows Display specified
value Designation/diagnosis
Basic setting
44
1 2 3 4 X _ X _ X X X X 1 = Diagnosis status

400 - 640 C
2 = Calculated temperature in three way catalytic converter (calculated value inside
the engine control module)
X X X X X X X X 3 = Diagnostic conditions 1 for three way catalytic converter diagnosis
X X X X X X X X 4 = Diagnostic conditions 2 for three way catalytic converter diagnosis
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01-259

Step 1: Preparation

- Start engine and let idle.

- Connect VAG 1551 or VAG 1552 scan tool,
switch on printer and select address word 01 (
page 01
-7 )

- Check and erase DTC memory ( page 01
-
13
).

No malfunctions may be stored. If necessary:

- Repair malfunctions.

- Erase DTC memory.

- Stop engine and start again.

- Test drive and, as a check, check and erase
DTC memory again.

- After checking and erasing DTC memory, let
engine run at idle again.
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