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Technical Service Bulletin
SUBJECT:

TC−SST TRANSMISSION AND MECHATRONIC
ASSEMBLY DIAGNOSIS & REPAIR PROCEDURES

No:

TSB−13−22−001

DATE:

January, 2013

MODEL:

See below

CIRCULATE TO:

[ ] GENERAL MANAGER

[ X ] PARTS MANAGER

[ X ] TECHNICIAN

[ X ] SERVICE ADVISOR

[ X ] SERVICE MANAGER

[ X ] WARRANTY PROCESSOR

[ ] SALES MANAGER

PURPOSE
Procedures are now available for W6DGA TC−SST Mechatronic Assembly (valve body and transmission
control module) replacement. This TSB provides the necessary steps to complete diagnosis, replace the
Mechatronic Assembly, and program the new electronic control unit.
Until now, authorized repairs for the TC−SST were limited to replacement of axle seals, transmission oil
pan and gasket, and the external oil filter. With the addition of Mechatronic Assembly replacement,
dealers no longer have to replace the transmission assembly to address the most common TC−SST
symptoms.
This TSB covers the following subjects:
1. An overview of the TC−SST operation (page 2).
2. Diagrams of the transmission showing selected replacement parts (page 4).
3. A Customer Interview Worksheet to be used by dealer service personnel to identify specific
transmission concerns (page 6).
!! IMPORTANT !! You are required to submit a completed customer interview sheet to Techline
for parts release.
4. Transmission troubleshooting instructions (page 7).
5. Mechatronic assembly replacement instructions including TCM programming (page 14).
6. A Quality Control Checklist to verify proper repair (page 41).
7. Part number information (page 42).
Diagnosis and repairs for DTCs and other symptoms not covered by this TSB may require transmission
replacement. For TC−SST diagnosis and repairs not covered by this TSB, contact Techline for assistance.
NOTE: Unlike most Mitsubishi electronic control units, a new Mechatronic assembly’s TCM is not
programmed with operating software. When a new Mechatronic assembly is installed, the
technician must program it following the steps provided in this TSB.
Repairs to the TC−SST are limited to the following:
D

Mechatronic assembly replacement and programming

D

Teach−in procedure for all model years (2008 Lancer Evolution is unique)

D

External oil filter/housing replacement

D

Axle seal replacement

D

Oil pan and pan seal replacement

AFFECTED VEHICLES
2008 – 2013 Lancer Evolution with TC−SST
2009 – 2013 Lancer Ralliart Edition with TC−SST
2009 – 2011 Lancer Sportback Ralliart Edition with TC−SST
Continued
Copyright 2013, Mitsubishi Motors North America, Inc.

(3955)

The information contained in this bulletin is subject to change. For the latest version of this document, go to the Mitsubishi Dealer Link,
MEDIC, or the Mitsubishi Service Information website (www.mitsubishitechinfo.com).

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TSB−13−22−001

TC−SST OPERATION OVERVIEW
The Mitsubishi TC−SST is an automated, 6−speed manual transmission. It contains the mechanical
gearing, hydraulic control (valve body) and the transmission control module (TCM). The valve body and
TCM are known as the Mechatronic Assembly. They are permanently attached to each other and cannot
be replaced separately.
The TC−SST distributes power in a manner similar to any other manual transmission. It uses gears with
brass synchronizers controlled by shift rails and forks to transmit power to the drive wheels. However, the
TC−SST uses two gear shafts; one for odd numbered gears and one for even numbered gears. The
automated portion of the transmission incorporates hydraulic servos to move the shift forks that engage
the gears, magnetic sensors to inform the TCM of shift fork positioning, other sensors to monitor clutch
pack speed, a valve body to direct hydraulic oil flow to appropriate points, and wet clutches (one per shaft)
to engage or disengage the odd or even gear shaft at the correct time.
The wet clutch system performs a similar function to a torque convertor in an automatic transmission. The
clutches are fully disengaged to allow the vehicle to idle, or engaged one at a time, allowing engine torque
to be transmitted through the gears on either the odd or even gear shaft.
The advantages of using the twin clutch setup are:
D increased shift speed
D reduced torque loss during shifts
D improved fuel economy
Shift Pattern
The driver can select either “Automatic Mode” or “Manual Mode” using the shift lever.
Automatic Mode

Shift knob

Manual Mode

Shift Lever Position

In automatic mode, the transmission shifts gears based
on shift mapping programmed into the transmission
control module, similar to a conventional automatic
transmission. In the manual mode, sequential gear
shifting is performed using either the floor shifter (+ for
upshifts, — for downshifts), or the steering column
mounted paddle shifters (right hand for upshifts, left hand
for downshifts).

Paddle Shift Operated

Shift Mode

No

Automatic mode

D Range

Yes

Shifting gears switches to manual mode.
NOTE: Returns to automatic mode when
vehicle speed drops to 6.25 mph (10 km/h).
If the right hand shift paddle is pulled and held
for more than 2 seconds, manual mode is cancelled.

Manual Shift Gate (+/—)

No/Yes

Manual mode
NOTE: In manual mode, as the vehicle slows,
the TCM automatically commands downshifts
to select a gear appropriate to vehicle speed.

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TSB−13−22−001

Throttle
opening (%)
100

UPSHIFT SCHEDULE (Automatic Mode)

DOWNSHIFT SCHEDULE (Automatic Mode)

Throttle
opening (%)
100

1

2

2

3

3

4

4

5

5

2

6

3
5
3

1
50

4

4

6

5

2

50

0

31

62

93

100

0

31

Vehicle Speed (mph)

62

93

100

Vehicle Speed (mph)

Drive Mode
Ralliart models have two drive modes: Normal and Sport.
Lancer Evolution models have three drive modes: Normal,
Sport and Super Sport.
When the engine is started, the drive mode defaults to
Normal.

TC−SST Control
Mode Switch

Each drive mode has a specific shift “feel.” The softest shift
feel occurs in the default Normal mode. In Sport mode,
shifts are quicker and occur at higher RPM. In Super Sport
mode, shifting is the most aggressive. Shifts occur at even
higher engine speeds and even more quickly than Sport
mode. (Super Sport is not recommended for normal street
use as shifting is very harsh).

Drive Mode

Shift Pattern
(Affects only Auto mode)

Clutch Response

Normal (Default)

Low Engine Speed Range

Sport

Middle Engine Speed
Quick
Range (2,500−4,000 RPM)

Quick

Super Sport

High Engine Speed Range Very Quick
(4,500−7,000 RPM)

Very Quick

Smooth

Accelerator Response
Smooth

Creep Function
The TCM is programmed to slip the clutches in both D and R ranges (a semi−engaged state) to enable
a creep drive condition similar to that provided by an automatic transmission torque convertor.
Kick Down Function
A kick down function (similar to an automatic transmission) is programmed into the TCM and allows
automatic downshifts when the accelerator pedal is fully depressed, providing quicker acceleration.

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Fast Off Function
Under normal circumstances, with the transmission in D range, when the accelerator pedal is suddenly
released, the transmission upshifts to better suit vehicle speed. However, under certain parameters, a
“fast off” function prevents upshifts in order to achieve engine braking.
Network Communication

ETACS

CAN C

CAN B
METER

ECM

TCM
LIN

The TC−SST, like most of the vehicle’s major
components, is constantly communicating with other
control units linked via the CAN C bus line. When
diagnosing electrical issues, it is important to focus on
proper electrical connections and communication. It also
means that, similar to the vehicle’s other control units,
MUT−III must be used to program the TCM after
replacement. Part of this TSB will focus on procedures
for proper coding when replacing Mechatronic
assemblies.

Shift Lever

ASC

ACD/AYC

Current Replacement Parts
The TC−SST transmission has two filter elements. Only
the external oil filter element and the Mechatronic
Assembly can be replaced at this time.
The combined Mechatronic Valve Body and TCM are
accessible under the oil pan.

Remove oil pan to access
Mechatronic assembly

External Oil Filter

DIAGNOSIS AND REPAIR OVERVIEW
Following is an overview of the diagnostic steps contained in this TSB. Specific procedures to be followed
in sequence begin on page 7. Do not perform diagnosis or repairs using this overview alone.
1. The Customer Interview Worksheet will help determine the specific transmission concerns.
!! IMPORTANT !! You are required to submit the worksheet to Techline for parts release. An
electronic copy can be downloaded from the “service tech resources” page of the MDL.
2. Perform a thorough visual inspection and check the basics.

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D

Note any transmission related MID display messages.

D

Check transmission fluid level and condition. Refer to the service manual for the proper
procedure.

D

Check Battery voltage (> 12.4V as measured at the battery).

D

Verify no electrical or performance accessories are installed.

D

Verify integrity of transmission electrical harness and associated connectors.

3. Connect MUT−III to the vehicle.
NOTE: If engine ECU or TCM tampering is suspected, contact your DPSM and Techline with the details.
D

Perform CAN bus check.

D

Record DTCs and Freeze Frame Data. Then perform Erase and Read DTCs.

4. Road test the vehicle to verify the concern and duplicate any previously retrieved DTCs.
5. If DTCs listed on page 8 are present after the road test, perform Transmission Control Module (TCM)
“Copy Coding” to MUT−III in preparation of replacing the Mechatronic assembly.
!! IMPORTANT !! DO NOT remove the transmission prior to performing copy coding.
NOTE: Using Copy Coding is highly recommended. If Copy Coding is not used, Download Coding,
which requires additional programming for any installed accessories, must be completed.
If Download Coding is necessary, use the correct TCM part number from the following table.
VEHICLE

TRANSMISSION
PART NO.

TCM SOFTWARE PART NO.

2009 Lancer Ralliart

2500A124

8631A513

2010 Lancer/Lancer Sportback Ralliart

2500A306

8631A860

2011−12 Lancer/Lancer Sportback Ralliart

2500A344

8631A972

2008 Lancer Evolution

2500A137

8631A379

2009 Lancer Evolution

2500A277

8631A763

2010 Lancer Evolution

2500A305

8631A827

2011−12 Lancer Evolution

2500A343

8631A971

6. Replace the Mechatronic assembly.
7. Program the Transmission Control Module (TCM).
8. Perform VIN Writing for new Transmission Control Module (TCM).
9. Perform “On Vehicle Coding” from MUT−III to TCM using data copied in step 5 above.
10. Perform “Teach−In” procedure.
11. Road test the vehicle to verify repair.
12. Complete Quality Control Checklist.

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CUSTOMER INTERVIEW WORKSHEET FOR TC−SST TRANSMISSION
Submitting a completed Customer Interview Worksheet to Techline is required for parts release.
Fax the completed worksheet to 714.934.4279 (in Canada: 905.214.9089).
VIN ___________________________ Dealer Code _________ Techline Case # __________
D Have any aftermarket devices been installed on this vehicle? Yes or No (circle one)
(e.g.: engine or transmission modifications, navigation units, gauges, tracking devices, etc.)
D Approximate Date/Time symptom occurred: _______________________________________
D
D
D

Continuous or Intermittent concern (circle one)
Weather (circle one): Wet or Dry
Road conditions (circle selections): Wet or Dry