transmission AUDI A8 1997 D2 / 1.G AEB Engine Additional Signal

At wide open throttle the A/C compressor is
switched off by the Transmission Control
Module (TCM) (kick down switch).
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Continuation
If the displayed values are NOT OK:

- Connect VAG 1598/22 test box to ECM harness
connector Page 01
-56
.

- Check wiring for open circuit, short circuit to B+
or short circuit to Ground between ECM/test box
terminal 8 and A/C control head -E87-, or
Transmission Control Module (TCM).

Electrical Wiring Diagrams, Troubleshooting &
Component Locations If the wiring is OK:

- Check function of A/C control head -E87-.

Repair Manual, Heating & Air Conditioning,
Repair Group 01

Or:

Repair Manual, 5 Spd. Automatic
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Transmission 01V, Repair Group 01


- Check readiness code Page 01-59
. If
Diagnostic Trouble Code (DTC) memory has
been erased, or ECM was disconnected,
generate new readiness code Page 01
-62
.
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The speed signal is generated by the vehicle
speed sensor (at the transmission), and
processed at the speedometer/odometer in the
instrument cluster.
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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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If the LED lights up continuously or does not light
up at all:

- Check wiring for open circuit, short circuit to Ground or short circuit to
B+ between ECM/test box socket 22 and multi-function Transmission
Range (TR) program switch -F125-.
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If the wiring is OK:

- Check multi-function Transmission Range (TR)
program switch -F125-.

Repair Manual, 5 Spd. Automatic
Transmission 01V, Repair Group 01


- Check readiness code Page 01
-59
. If
Diagnostic Trouble Code (DTC) memory has
been erased, or ECM was disconnected,
generate new readiness code Page 01
-62
.
Explanation of 4-digit display
Explanation when display field is = 0
x
x
x
x
(Display group 56)
0 A/C compressor off (0 = A/C compressor off / 1 = A/C compressor on)
0 Selector lever in P or N (0 = selector lever in P or N /1 = selector lever in 2/3/4/R/D)
0 Always "0"
0 Always "0"
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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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Continuation

Note:
The wiring to the Transmission Control Module is
monitored by On Board Diagnostic and stores
the Diagnostic Trouble Code 00545 if there is a
malfunction.
If displayed value is NOT OK (not as specified),
or if DTC 00545 is stored in DTC memory:

- Connect VAG 1598/22 test box to ECM harness
connector Page 01
-56
.

Electrical Wiring Diagrams, Troubleshooting & Component Locations - Check wiring for short circuit or open circuit between ECM harness
connector terminal 23 and to Transmission Control Module (TCM),
according to wiring diagram
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