The automatic transmission can exhibit any of the
following symptoms: noise or vibration is generated,
transmission fluid leaks, the vehicle does not move
forward or backward. The causes of these symptoms
could come from: Incorrect mounting, the transmis-
sion fluid may be low, or a component of the trans-
mission may be faulty.

The following items are suspected as causes for the
INVECS-II troubles: malfunction of the PCM, the
sensors, the switches, the harness or connectors.

Gather information from customer.

Check the transmission fluid.

Verify complaint.

Replace or replenish the
transmission fluid.

Communication with the scan tool
(MUT-II) not possible in Symptom
Chart.

Read the diagnostic trouble code.

Erase the diagnostic trouble code.

Check symptom.

Perform the repair.

Road test

Recheck diagnostic trouble codes
which were read before road test.

To DIAGNOSTIC TROUBLE CODE
CHART

To SYMPTOM CHART

Search for cause.

Repair

Confirmation test (road test)

INTERMITTENT MALFUNCTIONS
(Refer to GROUP 00, How to Use
Troubleshooting/Inspection
Service Points.)

Completed

Communication with the scan
tool (MUT-II) not possible

Diagnostic trouble code
displayed.

No diagnostic trouble code
displayed.

Abnormality exists (no diagnostic
trouble code)

Abnormality exists
(diagnostic trouble
code present)

No abnormality

No diagnostic trouble code
displayed.

Diagnostic trouble code
displayed.

Found

Not found

AC205501

AUTOMATIC TRANSMISSION DIAGNOSIS

TSB Revision

AUTOMATIC TRANSMISSION DIAGNOSIS

23Ab-3

INTRODUCTION TO A/T KEY INTERLOCK AND SHIFT LOCK MECHANISMS

M1232001600196

If the key interlock and shift lock mechanisms indi-
cates a malfunction, the key interlock cable, the shift
lock cable, or the selector lever assembly may be
defective. In this case, follow troubleshooting below.

A/T DIAGNOSITC TROUBLESHOOTING STRATEGY

M1231108500105

Use these steps to plan your diagnostic strategy. If
you follow them carefully, you will find most A/T mal-
functions.
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

Codes (DTCs).

4. If you can not verify the condition and there are no

DTCs, 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

DTCs, or the system can not communicate with
scan tool MB991502, refer to Symptom Chart

P.23Ab-32

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

then erase the code from memory using scan tool
MB991502.

7. Reconfirm the symptom with a Road Test.
8. If a DTC is set again, go to the Inspection Chart

for Diagnostic Trouble Codes.

9. If a 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 conditions to confirm the
malfunction has been eliminated.

A/T KEY INTERLOCK AND SHIFT LOCK MECHANISM DIAGNOSTIC
TROUBLESHOOTING STRATEGY

M1232001700193

Use these steps to plan your diagnostic strategy. If
your follow then carefully, you will be sure that you
have exhausted most of the possible ways to find
automatic transmission key interlock and shift lock
mechanism fault.
1. Gather information from the customer.

2. Verify that the condition described by the

customer exists.

3. Find the malfunction by following the Symptom

Chart.

4. Verify malfunction is eliminated.

A/T DIAGNOSITC TROUBLE CODE DIAGNOSIS

M1231108600094

CHECK "N" RANGE LIGHT

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

Input shaft speed sensor

Output shaft speed sensor

Each solenoid valve

Gear incorrect ratio

A/T control relay system

ACX01849AC

AUTOMATIC TRANSMISSION DIAGNOSIS

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AUTOMATIC TRANSMISSION DIAGNOSIS

23Ab-4

CAUTION

If the "A/T TEMP" indicator light is illuminated, it means
that the transmission fluid temperature is too high. Stop
the vehicle in a safe place and wait until the "A/T TEMP"
indicator light extinguishes.

ON-BOARD DIAGNOSTICS

The powertrain control module (PCM) monitors its
input/output signals (some signals all the time and
others under specified conditions). When an irregular
signal is initially monitored, the PCM decides that a
malfunction has occurred and records the occur-
rence has diagnostic trouble code. There are 26
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 even if the ignition switch is in

the "LOCK" (OFF) position. 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 scan
tool MUT-II (MB991502).
NOTE: If a sensor is disconnected when the ignition
switch is in the "ON" position, a diagnostic trouble
code is stored in memory. In this case, erase the
DTC using scan tool MB991502.
The 26 diagnostic items are displayed in numeric
order.

HOW TO READ AND ERASE DIAGNOSTIC
TROUBLE CODES

Required Special Tool:

• MB991502: Scan Tool (MUT-II)

CAUTION

To prevent damage to scan tool MB991502, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991502.
NOTE: If the battery positive voltage is low, diagnostic trouble
codes will not be output. Check the battery if scan tool
MB991502 dose not 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 scan tool MB991502 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Record the diagnostic trouble codes for (DTCs) A/T.
4. Refer to

P.23Ab-31

, Diagnostic Trouble Code Chart.

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

to the "ON" again.

6. Erase the diagnostic trouble code by selecting DTC erase

from SPECIAL MENU screen, using scan tool MB991502.

7. Check for diagnostic trouble codes. Confirm scan tool

MB991502 displays "normal."

8. Turn the ignition switch to the "LOCK" (OFF) position.
9. Disconnect scan tool MB991502.

ACX01539AD

MB991502

16-PIN

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