Page 3 of 366

01-2
On Board Diagnostic (OBD) II technical data
Memory
Permanent memory (If the engine control module is disconnected from the permanent battery positive voltage (B+) supply,
the Diagnostic Trouble Code (DTC) memory and "Readiness Code" will be erased.)
Data output
Rapid data transfer
Additional malfunction display by Malfunction Indicator Light (MIL) lighting up
Address words
Address word 00: Automatic Test Sequence Switch ignition on or let engine idle
Address word 01: Engine Electronics Switch ignition on or let engine idle
Address word 33: OBD II Switch ignition on or let engine idle
Functions under address word 01:
Function
01: Check Control Module
Versions Switch ignition on or let engine idle
Function
02: Check DTC Memory Let engine idle, or, crank engine with starter for at least 5 sec. without
switching ignition off
Function
03: Output Diagnostic Test
Mode Switch ignition on
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01-5
Malfunction recognition and repair
Notes:
Before initiating the On Board Diagnostic (OBD) program, and before testing wiring and replacing components, check the
following ground connections for corrosion and damaged connections and repair them if necessary
- Check ground connections on intake manifold
- Battery ground strap OK
- Ground cable between engine and body OK Malfunction recognition and repair is described for the VAG 1551 scan tool, since it offers significantly more functions.
However, malfunction recognition and repair is also possible with a "generic" scan tool.
A specific procedure must be used to evaluate malfunctions, since the engine electronics can be checked with address
word 01 and address word 33 on OBD II vehicles. Address word 33 can only be used to check malfunctions that have
already switched on the Malfunction Indicator Light (MIL). Address word 01 can also display the malfunctions that have
not switched on the MIL. In contrast to before, the MIL is not switched on immediately with some malfunction types, but
only after two successive trips with cold starts preceding them where the malfunction occurs. If there is a customer
complaint and/or driving performance problem, the DTC memory should be checked thoroughly with address word 01,
function 02. On vehicles with MIL lit up, the DTC memory should also be checked with address word 33, mode 3. If the
DTC memory is checked with mode 3, mode 2 should also be checked which shows the operating conditions as they were
when the malfunction was recognized.
If a malfunction is present for longer than a specified time, the malfunction is stored as a static malfunction. Malfunctions
that never or immediately switch the MIL on are set as "sporadic" at each engine start. If the malfunction occurs again, the
"sporadic" status is erased again. The "sporadic" status is erased exclusively after an OK diagnosis for malfunctions that
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jection
(MFI
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The malfunction "P0135 / 16519" is set as soon after engine start as the heating current, at a battery voltage between 9
volts and 16 volts is between 280 and 520 mA for longer than 1 sec (battery voltage fluctuations).
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(MFI
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The malfunction "P1102 / 17510" is set after engine start as soon as the heating current is greater than 10 A for longer
than 80 ms at a battery voltage between 9 V and 16 V.
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Page 132 of 366
The malfunction "P1107 / 17515" is set after engine start as soon as the heating current is greater than 10 A for longer
than 80 ms at a battery voltage between 9 V and 16 V.
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01-138
Output on GST and/or on
VAG 1551 scan tool Possible malfunction cause
Malfunction repair
P1600 / 18008
Power Supply (B+)
Terminal 15
Low Voltage Battery discharged or faulty
Repair Manual, Electrical
Equipment, Repair Group 27
- Check and charge battery
Malfunction cause found: Yes
No
- Erase DTC memory, test drive and
after test drive, check DTC memory
again
MIL Status:
Malfunction not displayed
by MIL Bad ground connection to Engine Control
Module (ECM) -J192-
- Check voltage supply to the Engine
Control Module (ECM) -J192-
page 28
-27
Malfunction cause found: Yes
No
- Erase DTC memory, test drive and
after test drive, check DTC memory
again
Excessive current draw with ignition off (e.g.
because of luggage compartment light on
continuously, etc.)
- Carry out holding current test. The
holding current must be greater than
50 mA
For troubleshooting
Display group 001
Malfunction cause found: Yes
No
- Erase DTC memory, test drive and
after test drive, check DTC memory
again
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) - Multi
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jection
(MFI
)
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01-139
Malfunction on generator or
controller
- Check generator and controller
Malfunction cause found: Yes
- Erase DTC memory, test drive and after test drive, check DTC memory
again
Notes:
If the malfunction "18008" is displayed as a sporadic error, disregard malfunction display! This malfunction can be stored
when the engine runs for a fairly long time in idle with a lot of consumers on if the battery is quite discharged.
The malfunction "18008" is set as soon as the supply voltage lies under 10.08 V for longer than 1 sec (the control module
does not operate under 6.5 V).
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Page 189 of 366

01-140
Output on GST
and/or on VAG
1551 scan tool Possible malfunction cause
Malfunction repair
P1602 / 18010
Power Supply (B+)
Terminal 30
Low Voltage The malfunction is set when the
battery/control module is disconnected
with ignition on or with a starting attempt
with ignition/control module
disconnected
- The malfunction is erased after the second engine
start if there is sufficient supply voltage. Therefore,
start car after battery/control module is
disconnected; shut off and start car again, then
check DTC memory again.
Malfunction cause found: Yes
No
- Erase DTC memory, test drive and after test drive,
check DTC memory again
MIL Status:
MIL lights up
immediately Poor ground connection between
battery and body
- Check ground cable for good contact on battery
terminal and check the threaded connection on the
body
Malfunction cause found: Yes
No
- Erase DTC memory, test drive and after test drive,
check DTC memory again
Break in the wiring connection
between battery and Engine Control
Module (ECM) -J192-
- Check voltage supply of engine control module
page 28
-27
Malfunction cause found: Yes
- Erase DTC memory, test drive and after test drive,
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ge 189 of 366 On Board Dia
gnostic
(OBD
) - Multi
port Fuel In
jection
(MFI
)
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.01.1