AUDI A4 2000 B5 / 1.G AFC Engine Auxiliary Input Signals Checking Owner's Guide

24-106

- Switch ignition ON.

- Using VAG 1551 scan tool, select "Read
Measuring Value Block" function 08, display
group 027, display field 1 page 01
-249
.
Read measuring value block 27 1 2 3 4

Indicated on display; note display field 1
If the specified value is not obtained, even though coding is OK: Specified value: 0
- Start engine and let idle.
Specified value: 1
-
Press button.- Select "End Output" function 06.
- Press -Q- button to confirm input.
- Connect VAG 1598/19 test box to ECM harness connector page 01
-
255
.
- Check wiring for open or short circuit between ECM and TCM, using
wiring diagram.
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24-107

Fuel level signal (from instrument
cluster), checking


Notes:

If the fuel level in the tank is too low (less than
3.2 gal); combustion misfire, oxygen sensor and
fuel system malfunctions could occur. In these
cases the malfunction "Fuel tank level too low"
is stored in DTC memory.
The fuel tank level signal is monitored by the
Engine Control Module (ECM).

Checking requirements:
Control Module coding OK page 01
-247
.

Fuel content greater than 3.2 gal (12 liters).
Instrument cluster fuel gauge OK.
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24-108

- Switch ignition ON.

- Using VAG 1551 scan tool, select "Read
Measuring Value Block" function 08, display
group 027, display field 2 page 01
-249
.
Read measuring value block 27 1 2 3 4

Indicated on display; note display field 2
If the specified value is not obtained, even though coding is OK: Specified value: 0
- Start engine and let idle.
Specified value: 1
-
Press button.- Select "End Output" function 06.
- Press -Q- button to confirm input.
- Connect VAG 1598/19 test box to ECM harness connector page 01
-
255
.
- Check wiring for open or short circuit between ECM and instrument
cluster, using wiring diagram.
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24-109

Rough road condition signal, checking


ABS control module with ABS/EDL

Notes:

Misfires can result in malfunctions such as
"Combustion misfire" being recorded in DTC
memory due to road wheel malfunctions.
If the ABS control module recognizes a free
turning wheel, it generates a rough road signal.
If the Engine Control Module (ECM) recognizes
the rough road signal, misfire recognition is
switched off in the ECM.
The rough road signal is created to check
whether DTC 18014 "Rough Road Spec Engine
Torque ABS-SG Electrical Malfunction" is
stored in DTC memory. The "Combustion
misfire" malfunction results from this signal and
can be ignored.
The rough road signal is monitored by the
ECM.

Checking requirement

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Control module coding OK page 01
-247
.

Checking

- Switch ignition OFF.

- Connect VAG 1598/19 test box to ECM harness
connector page 01
-255
.

- Check signal wire for open or short circuit
between ECM and ABS control module, using
wiring diagram.
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24-110

- Find and eliminate open or short circuit; repair
as necessary.
If wiring is OK:

- Replace ABS control module.
If the ABS control module is OK, but the
malfunction is still occurring:

- Replace ECM page 01
-265
.

ABS control module with ABS/EDL/ASR

Notes:

The torque signal is monitored by the
"Automatic Traction Control" Control Module
and by the ECM.

Repair Manual, Brake System On Board
Diagnostic (OBD), Repair Group 01


Vehicles with automatic traction control (ASR)
can be recognized by the ASR indicator light in
the instrument cluster or by control module
identification displayed during the ABS On
Board Diagnostic program sequence.
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Repair Manual, Brake System On Board
Diagnostic (OBD), Repair Group 01


Checking requirement

Control module coding OK page 01
-247
.
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pair&id=AUDI.B5.FU01.24.25