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A/T Controls - Fault Tracing DTC AT-412 (TCM)

SECTION
4

GROUP
43

NO
929

DATE
July -98

RE: Supplement to Service
Manual Section 4(43)
960 1996-
S90/V90 1997-

REFERENCE: TP 4313201, SECTION 4(43) AUTOMATIC TRANSMISSION AW 30-40/30-43; 960 1996-

Supplement to Service Manual Section 4(43)

Background:

This Service Bulletin is a supplement to Service Manual Section 4(43) Automatic transmission AW 30-40/30-43 960 1996-, TP 4313201.

From and including model year 1997 the automatic transmission control module (TCM) for markets where the on-board diagnostic (OBD) system OBD is a statutory requirement has been updated. A new diagnostic trouble code (DTC) has been added and some of the existing diagnostic trouble codes (DTCs) AT-331, AT-332, AT-333 and AT-341 have been classified according to OBD II (now has OBD II code).

This Service Bulletin contains information on board OBD II coding and fault-tracing for the new diagnostic trouble code (DTC) AT-412. For other information on the automatic transmission, see the Service Manual.





AT-412 Control module





Diagnostic trouble code (DTC) information

Conditions

Each time the ignition is switched on, the control module checks the memory circuit ROM. It the control module registers a fault in the memory circuit, the Diagnostic trouble code (DTC) AT-412 is stored the second time the ignition is switched on.

Substitute value
^ None

Cause of fault
^ Fault in control module

Fault symptom
^ The combined instrument panel warning lamp flashes.

Note!
The Motronic 4.4 engine control module (ECM) posts a diagnostic trouble code (DTC) when the transmission sends a malfunction indicator lamp (MIL) request. Erase this diagnostic trouble code (DTC) in the Motronic engine control module (ECM) when the transmission fault has been repaired.

Fault-tracing begins with 1.

Fault in memory








1
Checking diagnostic trouble code (DTC) status

Switch the ignition on arid off a few times.

Ignition on.

Read off the diagnostic trouble code (DTC) counters.

Is counter value greater than 0 (zero)?

YES
^ 3

NO
^ 2

2

Replacing component

Ignition off.

Test a new control module according to "Transmission control module (TCM), replacing" in the Service Manual.

Then continue with.
^ The fault is remedied

3
Replacing component

The control module previously stored a fault. The memory circuit is now OK. No further corrective action

Then continue with:
^ The fault is remedied

WARRANTY STATEMENT: Warranty may be submitted under the new car factory warranty when there is a documented customer complaint using claim type 01.

Operation No. Labor description Time allowance

43761-3 Automatic transmission 0.1 hr
fault-tracing diagnostic
trouble code (DTC) (AT)