check engine AUDI A6 1999 C5 / 2.G AEB Engine Additional Signal

24-146

Checking

- Connect VAG 1551 or VAG 1552 scan tool and
press buttons -0- and -1- to insert "Engine
Electronics" address word 01 (with engine
running at idle) Page 01
-7 .
Rapid data transfer
HELP
Select function XX

Indicated on display
- Press buttons -0- and -8- to select "Read Measuring Value Block"
function 08, and press -Q- button to confirm input.
Read Measurin
g Value Block
HELP
Input displa
y group number XXX

Indicated on display
- Press buttons -0-, -5- and -0- to input display group number 50, and
press -Q- button to confirm input.
Read Measuring Value Block 50 1 2 3 4

Indicated on display (1-4 = display fields)
- Switch on A/C (lowest temperature and highest fan position).
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24-153

Transmission Range (TR) signal,
checking


Notes:

Through the multi-function Transmission Range
(TR) program switch -F125- at the transmission,
the Engine Control Module (ECM) recognizes
whether a drive range is selected (selector lever
in 2/3/4/R/D) or not (selector lever in P or N)
The multi-function Transmission Range (TR)
program switch -F125- at the transmission
switches to Ground through terminal 22 of the
ECM when the shift lever is in N or P.
When a drive range is selected, the switch
opens and terminal 22 now has power.

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

Test procedure

-
Connect VAG 1551 or VAG 1552 scan tool and
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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
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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.
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