instrument cluster AUDI A4 1997 B5 / 1.G AFC Engine Auxiliary Input Signals Checking Workshop Manual
[x] Cancel search | Manufacturer: AUDI, Model Year: 1997, Model line: A4, Model: AUDI A4 1997 B5 / 1.GPages: 37, PDF Size: 0.15 MB
Page 12 of 37

24-94
Engine speed (RPM) signal, checking
Notes:
The RPM signal is routed from the ECM to
various electronic systems (e.g. automatic
transmission, ABS, etc.). The RPM signal is
monitored by the different electronic systems.
Carry out the following check only if the
tachometer (in the instrument cluster) is
inoperative, or if the A/C compressor is not
running.
- Connect VAG 1367 engine-tester to tachometer
using wiring diagram.
- Connect VAG 1367 engine-tester signal wire
(green terminal) to instrument cluster RPM
terminal and A/C control module RPM terminal
(connector remains connected).
- Start engine and let idle.
RPM must be displayed again
If the specified value is obtained, the malfunction
is in instrument cluster or on A/C control module.
If the RPM is not displayed on VAG 1367 engine-
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Page 13 of 37

tester:
- Check wiring between ECM terminal C10 and
instrument cluster or A/C control module using
wiring diagram.
If wiring is OK:
- Replace ECM page 01
-265
.
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Page 14 of 37

24-95
Fuel consumption signal, checking
Notes:
The consumption signal is internally calculated
by the ECM using "injection time."
The consumption signal is routed to both the
trip computer and the Transmission Control
Module (TCM).
The consumption signal is monitored by the
TCM
Repair Manual, 5 Spd. Automatic
Transmission 01V, Repair Group 01; On Board Diagnostic
Carry out the following check only if DTC
memory contains a stored DTC for the TCM
related to the consumption signal, or a missing or
false consumption signal, determined during the
trip computer check.
- Remove instrument cluster or TCM.
Repair Manual, Electrical Equipment, Repair
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Page 15 of 37

Group 90; Instrument cluster, repairing
Repair Manual, 5 Spd. Automatic
Transmission 01V, Repair Group 01, On Board Diagnostic
- Connect VAG 1598 test box to instrument
cluster harness connector (I/P insert not
connected) or to TCM harness connector (TCM
not connected).
Repair Manual, Electrical Equipment, Repair
Group 90; Instrument cluster, repairing
Repair Manual, 5 Spd. Automatic
Transmission 01V; Repair Group 01, On Board Diagnostic
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Page 18 of 37

24-97
Vehicle speed signal, checking
Note:
The vehicle speed signal originates from the
vehicle speed sensor (on the transmission) and
is routed to the instrument cluster as well as to
the Engine Control Module (ECM).
Speedometer in instrument cluster OK
Checking
- Using VAG 1551 scan tool, select "Read
Measuring Value Block" function 08, display
group 003 page 01
-249
.
Read measuring value block 3 1 2 3 4
Indicated on display
- Observe display field 4 while accelerating from standstill.
Specified values:
0 mph (at standstill)
Actual speed (vehicle driven)
-
Press button.
- Select "End Output" function 06.
- Press -Q- button to confirm input.
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Page 30 of 37

24-105
Malfunction Indicator Lamp (MIL) wire
from Transmission Control Module
(TCM), checking
Notes:
If a malfunction is recognized by the Engine
Control Module (ECM) or the Transmission
Control Module (TCM), it is indicated by the
Malfunction Indicator Lamp (MIL) in the
instrument cluster.
If the TCM recognizes a malfunction, the MIL is
switched on via the ECM.
The MIL wiring is monitored by the ECM.
Checking requirement
Control module coding OK page 01
-247
.
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Page 32 of 37

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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Page 33 of 37

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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Page 36 of 37

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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