Mitsubishi Eclipse / Eclipse Spyder (2000-2002). Service and repair manual — part 431

AUTOMATIC TRANSAXLE DIAGNOSIS

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AUTOMATIC TRANSAXLE

23A-15

1. Gather as much information as possible about the

complaint from the customer.

2. Verify that the condition described by the

customer exists.

3. Check the vehicle for any A/T Diagnostic Trouble

Code (DTC).

4. If you cannot verify the condition and there are no

DTC, the malfunction is intermittent. For
information on how to cope with intermittent
malfunctions, refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points

−

How

to Cope with Intermittent Malfunction

P.00-6

.

5. If you can verify the condition but there are no

DTC, or the system cannot communicate with the
scan tool, refer to Symptom Chart.

6. If there is a DTC, record the number of the code,

then erase the code from memory using the scan
tool.

7. Reconfirm the symptom using the Road Test.

8. If DTC is set again, go to Inspection Chart for

Diagnostic Trouble Codes.

9. If DTC is not set again, the malfunction is

intermittent. For information on how to cope with
intermittent malfunctions, refer to GROUP 00,
How to Use Troubleshooting/Inspection Service
Points

−

How to Cope with Intermittent

Malfunction

P.00-6

.

10.After repairs are completed, conduct a Road Test

duplicating the complaint set conditions to confirm
the malfunction has been eliminated.

A/T DIAGNOSTIC TROUBLE CODE DIAGNOSIS

M1231007700068

CHECK "N" RANGE LIGHT <VEHICLES WITH
SPORT MODE>

The "N" range light flashes once per second if there is an
abnormality in any of the items in the table below which are
related to the A/T system. Check for diagnostic trouble codes if
the "N" range light is flashing once per second.

"N" range light flashing items

CAUTION

If the "N" range light is flashing twice per second, it means
that the A/T fluid temperature is too high. Stop the vehicle
in a safe place and wait until the "N" range light switches
off.

ON-BOARD DIAGNOSTICS

The powertrain control module (PCM) monitors its
input/output signals (some signals all time and others
under specified conditions). When an irregular signal
is initially monitored, the PCM decides that a
malfunction has occurred. There are 25 <Vehicles
without sport mode> or 26 <Vehicles with sport
mode> diagnostic items. The diagnostic results can
be read with a scan tool. Diagnostic trouble codes
are kept in memory by direct battery feed. The codes
are retained in memory if the ignition switch is

"LOCK" (OFF). Diagnostic trouble codes will,
however, be erased when a battery terminal or the
PCM connector is disconnected. In addition, the
diagnostic trouble code can also be erased by the
scan tool MUT-II (MB991502).

NOTE: If a sensor is disconnected with the ignition
switch is "ON," a diagnostic trouble code is
memorized. In this case, erase the DTC using the
scan tool.
The 25 <Vehicles without sport mode> or 26
<Vehicles with sport mode> diagnostic items are all
indicated sequentially from the smallest code
number.

Input shaft speed sensor

Output shaft speed sensor

Each solenoid valve

Gear incorrect ratio

A/T control relay system

AC001816

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HOW TO READ AND ERASE DIAGNOSTIC
TROUBLE CODES

<When using the scan tool>

Required Special Tools:
MB991502: Scan Tool (MUT-II)

CAUTION

To prevent damage to scan tool MB991502, always turn the
ignition switch to "LOCK" (OFF) position before
connecting or disconnecting scan tool MB991502.

NOTE: If the battery positive voltage is low, diagnostic trouble
codes will not be output. Check the battery if the scan tool
cannot display.

NOTE: If the battery is disconnected or if the powertrain
control module connector is disconnected, the diagnostic
trouble codes will be erased. Do not disconnect the battery or
powertrain control module before the diagnostic trouble codes
have been read.
1. Connect the scan tool to the data link connector.

2. Turn the ignition switch to "ON" position.

3. Record the diagnostic trouble codes for A/T.

4. Refer to the Diagnostic Trouble Code Chart.

5. Turn the ignition switch to "LOCK" (OFF) and then back to

"ON" again.

6. Erase the diagnostic trouble code by selecting DTC erase

from SPECIAL MENU screen, using scan tool.

7. Check for diagnostic trouble codes. Confirm the scan tool

displays "normal."

8. Turn the ignition switch to "LOCK" (OFF) position.

9. Disconnect the scan tool.
<When using the "N" range light (only for vehicles with
sport mode)>

Required Special Tool:
MB991529: Diagnostic Trouble Code Check Harness
1. Use special tool MB991529 to ground terminal number 1 of

the data link connector.

2. Turn on the ignition switch to "ON" position.

AC001252

MB991502

16 PIN

AB

AC001819

MB991529

DATA LINK
CONNECTOR

AB

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3. Read the diagnostic trouble codes by counting "N" range

light flashes.

4. Refer to the Diagnostic Trouble Codes Chart.

5. Erase the diagnostic trouble codes by the following

procedure.

(1) Turn the ignition switch to "LOCK" (OFF) position.
(2) Disconnect the negative battery cable for 10 seconds or

more. Reconnect the cable.

(3) Turn the ignition switch to "ON" position. Read the

diagnostic trouble code output and check that no
diagnostic trouble code is output.

(4) Start the engine and let it run until the engine has

warmed up. Run it at idle for approximately 10 minutes or
longer. The engine control module must build up the
adaptive memory for smooth idle and good performance.

UNDERSTANDING THE "N" RANGE LIGHT FLASHES <VEHICLES WITH SPORT
MODE>

NOTE: Other diagnostic trouble codes also are output by the flashing of the "N" range light corresponding to
the same code numbers as the scan tool displays.

INSPECTION USING SCAN TOOL, ROAD TEST
AND DATA LIST

Required Special Tool:
MB991502: Scan Tool (MUT-II)

AC001816

EXAMPLE OF FLASHING WHEN A DIAGNOSTIC
TROUBLE CODE IS OUTPUT

FLASHING WHEN NORMAL

AC001820 AB

FOR DIAGNOSTIC TROUBLE CODE No.23

LIGHT
ON
LIGHT
OFF

PAUSE
TIME

TENS
SIGNAL

PLACE
DIVISION

UNITS
SIGNAL

1.5 s 0.5 s

0.5 s

AC001823

LIGHT
ON
LIGHT
OFF

0.5 s

AB

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CAUTION

To prevent damage to scan tool MB991502, always turn the
ignition switch to "LOCK" (OFF) position before
connecting or disconnecting scan tool.
1. Connect the scan tool to data link connector.

2. Turn the ignition switch to "ON" position.

3. Carry out inspection by means of the Road Test or Data List

function. If there is an abnormality, check and repair the
chassis harnesses and components. Refer to

P.23A-20

,

Road Test. Refer to

P.23A-317

, Data List Reference Table.

4. Re-check using scan tool and check that the abnormal input

and output have returned to normal because of the repairs.

5. Erase the diagnostic trouble code(s).

6. Turn the ignition switch to "LOCK" (OFF) position.

7. Disconnect the scan tool from the data link connector.

8. Start the engine again and do a test drive to confirm that the

problem is eliminated.

FAIL-SAFE/BACKUP FUNCTION

M1231008300041

When malfunctions of the main sensors or actuators
are detected by the PCM, the transaxle is controlled
by pre-set control logic to maintain safe conditions
for driving.

AC001252

MB991502

16 PIN

AB

MALFUNCTIONING
ITEM

JUDGEMENT
CONDITION

CONTROL CONTENTS DURING MALFUNCTION

Input shaft speed sensor No output pulse from the

input shaft speed sensor is
detected for one second or
more when the vehicle
speed is 30 km/h (19 mph)
or more.

The diagnostic trouble code is displayed when the
judgement condition occurs once. When the
judgement condition is met four times, the transaxle
holds 3rd gear or 2nd gear depending on speed and
for vehicles with sport mode "N" range light flashes
as a fail-safe.

Output shaft speed
sensor

Output from the output
shaft speed sensor is
continuously 50 % or less
of the output from the
vehicle speed sensor one
second or more when the
vehicle speed is 30 km/h
(19 mph) or more.

The diagnostic trouble code is displayed when the
judgement condition occurs once. When the
judgement condition is met four times, the transaxle
holds 3rd gear or 2nd gear depending on speed and
for vehicles with sport mode "N" range light flashes
as a fail-safe.

Low-reverse solenoid
valve

Solenoid valve resistance
is below 2.7 W for 0.32
seconds.

When the judgement condition is met four times, the
A/T control relay is turned off and for vehicles with
sport mode "N" range light flashes.

Underdrive solenoid
valve

Second solenoid valve

Overdrive solenoid valve

Torque converter clutch
solenoid valve