check engine light AUDI A4 2001 B5 / 1.G 01V Transmission OBD Functions Workshop Manual

01-4

- The Multi-function Indicator Light (MIL) lights up
after 2 driving cycles (Dcy); check DTC memory
( page 01
-43
and compare with DTC table
page 01
-45
).
If the TCM -J217- malfunctions (e.g. if the power
supply is faulty or the connector becomes
disconnected), the transmission will immediately
switch to "mechanical back-up mode with
inactive control module" and continue to
operate.

Mechanical backup with non-active control
module

- The transmission shifts out of all forward gears
into hydraulic 4th gear. The torque converter
clutch is unlocked (not applied). All solenoid
valves are de-energized.

- Maximum shift pressure is applied to the power-
transmitting elements.

- Reverse gear can be engaged. The shift lock
solenoid is active (in "P" and "N").

- All of the segments transmission range selector lever display are dark.
-
The MIL lights up when the Engine Control Module (ECM) has
recognized a CAN-bus malfunction (missing data exchange between
engine and transmission control modules) (after 2 Dcy); check DTC
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01-5

Malfunction Indicator Lamp (MIL)
function, checking

If emissions malfunctions are recognized by the
TCM, the Malfunction Indicator Lamp (MIL) will
be switched on.

Location of the MIL: integrated in speedometer in instrument cluster
Notes:
When the MIL is switched on, it will either blink or light continuously. The
DTC memory for the TCM must be checked page 01
-43
.
MIL flashing: there is a malfunction that could damage the Three Way
Catalytic Converter (TWC). In this case, drive only with reduced
power. MIL continuously on: there is a malfunction that degrades emissions.
Check DTC memory of the Engine Control Module (ECM) or the TCM. If there are driveability problems (e.g. a customer complaint) and the
MIL is not on, perform the MIL functional because malfunctions can be
stored that do not switch the MIL on.
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01-6

MIL functional check

- Switch ignition on: MIL must come on.

If the MIL does not come on when the ignition is
switched on (with the engine not running):
Check DTC memory page 01
-43
. If
necessary, check wiring per wiring diagram or
replace light bulb.

- Start engine and let idle: MIL must switch off
after several seconds.

If the MIL does not switch off after the engine is
started: Check DTC memory page 01
-43
.
Pa
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gnostic
(OBD
), function
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play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.AT02.01.1