Mitsubishi Eclipse. Manual - part 834

AUTOMATIC TRANSAXLE DIAGNOSIS

TSB Revision

AUTOMATIC TRANSAXLE

23A-345

STEP 1. Using scan tool MB991958, check data list item 66: 
Overdrive Off Signal (Auto-cruise ECM Signal).

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector.
(2) Start the engine and prepare to test drive the vehicle. 

(Operate the auto-cruise)

(3) Set scan tool MB991958 to data reading mode for item 66: 

Overdrive Off Signal (Auto-cruise ECM Signal).

• When driving at level road, the display should be "OFF."

• When driving at uphill road, the display should be "ON."

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?

YES : It can be assumed that this malfunction can be 

intermittent. Refer to GROUP 00, How to Use 
Troubleshooting/Inspection Service Points 

− How to 

Cope with Intermittent Malfunction 

P.00-6

.

NO :  Go to Step 2.

STEP 2. Check the auto-cruise system.
Check the auto-cruise system. Refer to GROUP 17, 
Auto-cruise Control System Diagnostic Troubleshooting Strat-
egy 

P.17-8

.

Q: Is the auto-cruise system operating properly?

YES : Go to Step 3.
NO :  Repair it, then check the symptom.

AC303127

AB

MB991911

16-PIN

MB991827

MB991824 

AUTOMATIC TRANSAXLE DIAGNOSIS

TSB Revision

AUTOMATIC TRANSAXLE

23A-346

STEP 3. Measure the signal voltage at PCM connector C-57 
<2.4L Engine> or C-59 <3.0L Engine> by backprobing.
(1) Do not disconnect connector C-57 <2.4L Engine> or C-59 

<3.0L Engine>.

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

(3) Measure the voltage between terminal 75 and ground by 

backprobing.

• The voltage should measure battery positive voltage.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage battery positive voltage?

YES : Go to Step 6.
NO :  Go to Step 4.

AC001657

CONNECTOR: C-57 <2.4L ENGINE> OR 
C-59 <3.0L ENGINE>

AZ

PCM

C-57 <2.4L ENGINE> OR C-59 <3.0L ENGINE>

AC002097

C-57 <2.4L ENGINE> OR
C-59 <3.0L ENGINE>
HARNESS CONNECTOR:
HARNESS SIDE

AN

AUTOMATIC TRANSAXLE DIAGNOSIS

TSB Revision

AUTOMATIC TRANSAXLE

23A-347

STEP 4. Check PCM connector C-57 <2.4L Engine> or C-59 
<3.0L Engine> and inter mediate connector C-28 for looser, 
corroded or damaged terminals, or terminals pushed back 
in the connector.
Q: Are the connectors and terminals in good condition?

YES : Go to Step 5.
NO :  Repair or replace the damaged components. Refer to 

GROUP 00E, Harness Connector Inspection 

P.00E-2

.

AC001657

CONNECTOR: C-57 <2.4L ENGINE> OR 
C-59 <3.0L ENGINE>

AZ

PCM

C-57 <2.4L ENGINE> OR C-59 <3.0L ENGINE>

AC106611AB

CONNECTOR: C-28

C-28

AUTOMATIC TRANSAXLE DIAGNOSIS

TSB Revision

AUTOMATIC TRANSAXLE

23A-348

STEP 5. Check the harness for open circuit, short circuit to 
ground or damage between PCM connector C-57 <2.4L 
Engine> or C-59 <3.0L Engine> terminal 75 and auto-cruise 
control-ECU connector C-20 terminal 3.
Q: Is the harness wire in good condition?

YES : Go to Step 6.
NO :  Repair or replace the harness wire.

STEP 6. Measure the signal voltage at auto-cruise 
control-ECU connector C-20 by backprobing.
(1) Do not disconnect connector C-20.
(2) Turn the ignition switch to the "ON" position.

(3) Measure the voltage between terminal 3 and ground by 

backprobing.

• The voltage should measure battery positive voltage.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage battery positive voltage?

YES : Go to Step 7.
NO :  Go to Step 8.

AC001657

CONNECTOR: C-57 <2.4L ENGINE> OR 
C-59 <3.0L ENGINE>

AZ

PCM

C-57 <2.4L ENGINE> OR C-59 <3.0L ENGINE>

AC001741

CONNECTOR: C-20

AU

C-20

AC001741

CONNECTOR: C-20

AU

C-20

AC002119

C-20 HARNESS 
CONNECTOR: 
HARNESS SIDE

AM