torque AUDI A8 1999 D2 / 1.G AEB Engine Additional Signal

24-157

Timing control during shifting, checking


Notes:

When shifting the automatic transmission, this
signal from the Transmission Control Module
(TCM) retards the ignition timing briefly,
depending on vehicle speed and engine RPM
(reduction of torque), to reduce shift pressure.
Because of the very brief signal to reduce
torque, the signal is not always recognized by
the VAG 1551 scan tool, and therefore is not
always indicated.

Required special tools and test equipment
VAG 1551 or VAG 1552 Scan Tool (ST) with
VAG 1551/3 adapter cable
VAG 1598/22 test box
Pa
ge 21 of 29 Additional si
gnals
11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU02.24.5

24-159

- Compare display with specified value in display
field 4:

Display fields

1 2 3 4
Display group 122: Engine torque reduction during shifting
Display xxxx RPM xxx Nm xxx Nm TCS active
Motor enga
Indicates Engine speed
(in 40 RPM
steps) Required engine
torque
(Specified torque) Actual engine
torque
(Actual torque) Timing angle retard active or not active
Range 0-6800 RPM -100 to 410 Nm -100 to 310 Nm ---
Specified
value --- --- --- When shifting, "Motor enga" must be
displayed briefly

--- --- --- If not as specified Page 24
-160

If display is OK (as specified):

-
Press button to advance program
sequence.
- Press buttons -0- and -6- to select "End Output"
function 06, and press -Q- button to confirm
input.
Pa
ge 23 of 29 Additional si
gnals
11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU02.24.5

24-161

Rough road signal from ABS/EDL
control module, checking


Notes:

When the ABS/EDL control module senses a
wheel spinning, it produces the rough road
signal. When the ECM recognizes the rough
road signal, the misfire recognition is switched
off.
Check the rough road signal only when the
trouble code 18014 "Rough Road Spec Engine
Torque ABS-ECU Electrical Malfunction" is
stored. The "Misfire" malfunction is in this case
a subsequent malfunction that can be
disregarded.
The wiring and the rough road signal are
monitored by the ECM.
Emissions testing on a front-wheel drive vehicle
with ABS/EDL, during which only the front
wheels turn while the rear wheels are
stationary, can result in the DTC 18014 being
stored in DTC memory. Therefore, the fuse for
the ABS/EDL control module must be removed.
After the test, check DTC memory for the
ABS/EDL control module and the ECM. Then
erase DTC memory.
Pa
ge 26 of 29 Additional si
gnals
11/19/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU02.24.5