AT-56
[EURO-OBD]
TROUBLE DIAGNOSIS — INTRODUCTION
TROUBLE DIAGNOSIS — INTRODUCTION
PFP:00000
IntroductionECS004QO
The TCM receives a signal from the vehicle speed sensor, throttle
position sensor or PNP switch and provides shift control or lock-up
control via A/T solenoid valves.
The TCM also communicates with the ECM by means of a signal
sent from sensing elements used with the EURO-OBD related parts
of the A/T system for malfunction-diagnostic purposes. The TCM is
capable of diagnosing malfunctioning parts while the ECM can store
malfunctions in its memory.
Input and output signals must always be correct and stable in the
operation of the A/T system. The A/T system must be in good oper-
ating condition and be free of valve seizure, solenoid valve malfunc-
tion, etc.
It is much more difficult to diagnose a problem that occurs intermit-
tently rather than continuously. Most intermittent problems are
caused by poor electric connections or improper wiring. In this case,
careful checking of suspected circuits may help prevent the replace-
ment of good parts.
A visual check only, may not find the cause of the problems. A road
test with CONSULT-II (or GST) or a circuit tester connected should
be performed. Follow the “Work Flow”. Refer to AT- 6 0 , "
Work Flow" .
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a drive ability complaint. The cus-
tomer can supply good information about such problems, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A “Diagnostic Worksheet” like the exam-
ple (AT- 5 7 , "
DIAGNOSTIC WORKSHEET" ) should be used.
Start your diagnosis by looking for “conventional” problems first. This
will help troubleshoot drive ability problems on an electronically con-
trolled engine vehicle.
Also check related Service bulletins for information.
SAT631IA
SAT632I
SEF234G
AT-58
[EURO-OBD]
TROUBLE DIAGNOSIS — INTRODUCTION
Diagnostic Worksheet
1.❏ Read the Fail-safe and listen to customer complaints.AT-57, "Infor-
mation from
Customer"
2.❏ CHECK A/T FLUIDAT-63, "A/T
Fluid Check"❏ Leakage (Follow specified procedure)
❏ Fluid condition
❏ Fluid level
3.❏ Perform STALL TEST and LINE PRESSURE TEST.AT-64, "
Stall
Te s t",AT- 6 7 ,
"Line Pres-
sure Test"
❏ Stall test — Mark possible damaged components/others.
❏ Torque converter one-way clutch
❏ Reverse clutch
❏ Forward clutch
❏ Overrun clutch
❏ Forward one-way clutch❏ Low & reverse brake
❏ Low one-way clutch
❏ Engine
❏ Line pressure is low
❏ Clutches and brakes except high clutch and
brake band are OK
❏ Line Pressure test — Suspected parts:
4.❏ Perform all ROAD TEST and mark required procedures.AT-68, "
Road
Te s t"
4-1. Check before engine is started.AT-70, "1.
CHECK
BEFORE
ENGINE IS
STARTED"
❏ O/D OFF Indicator Lamp Does Not Come On, AT-209, "O/D OFF Indicator Lamp Does Not Come On" .
❏ SELF-DIAGNOSTIC PROCEDURE/DIAGNOSTIC TROUBLE CODE (DTC) CONFIRMATION PRO-
CEDURE. — Mark detected items.
❏ PNP switch, AT-110, "
DTC P0705 PARK/NEUTRAL POSITION (PNP) SWITCH" .
❏ A/T fluid temperature sensor, AT-116, "
DTC P0710 A/T FLUID TEMPERATURE SENSOR CIR-
CUIT" .
❏ Vehicle speed sensor·A/T (Revolution sensor), AT-122, "
DTC P0720 VEHICLE SPEED SEN-
SOR·A/T (REVOLUTION SENSOR)" .
❏ Engine speed signal, AT-127, "
DTC P0725 ENGINE SPEED SIGNAL" .
❏ Torque converter clutch solenoid valve, AT-158, "
DTC P0740 TORQUE CONVERTER CLUTCH
SOLENOID VALVE" .
❏ Line pressure solenoid valve, AT-163, "
DTC P0745 LINE PRESSURE SOLENOID VALVE" .
❏ Shift solenoid valve A, AT-170, "
DTC P0750 SHIFT SOLENOID VALVE A" .
❏ Shift solenoid valve B, AT-175, "
DTC P0755 SHIFT SOLENOID VALVE B" .
❏ Accelerator pedal position (App) sensor, AT- 1 8 0 , "
DTC P1705 ACCELERATOR PEDAL POSITION
(APP) SENSOR" .
❏ Overrun clutch solenoid valve, AT-185, "
DTC P1760 OVERRUN CLUTCH SOLENOID VALVE" .
❏ PNP & overdrive control switches, and throttle position sensor, AT- 2 4 1 , "
TCM Self-diagnosis Does
Not Activate" .
❏ Batt/fluid temp sen (A/T fluid temperature sensor and TCM power source), AT-193, "
DTC BATT/
FLUID TEMP SEN (A/T FLUID TEMP SENSOR CIRCUIT AND TCM POWER SOURCE)" .
❏ Vehicle speed sensor·MTR, AT-199, "
DTC VEHICLE SPEED SENSOR MTR" .
❏ CAN communication line, AT-190, "
DTC U1000 CAN COMMUNICATION LINE" .
❏ Control unit (RAM), control unit (ROM), AT- 2 0 3 , "
DTC CONTROL UNIT (RAM), CONTROL UNIT
(ROM)" .
❏ Control unit (EEP ROM), AT- 2 0 5 , "
DTC CONTROL UNIT(EEPROM)" .
❏ Battery
❏ Others
4-2. Check at idleAT-71, "
2.
CHECK AT
IDLE"❏ Engine Cannot Be Started In “P” And “N” Position, AT- 2 11 , "Engine Cannot Be Started In “P” and “N”
Position" .
❏ In “P” Position, Vehicle Moves Forward Or Backward When Pushed, AT-212, "
In “P” Position, Vehicle
Moves Forward Or Backward When Pushed" .
❏ In “N” Position, Vehicle Moves, AT-213, "
In “N” Position, Vehicle Moves" .
❏ Large Shock. “N” → “R” Position, AT-214, "
Large Shock. “N”→“R” Position" .
❏ Vehicle Does Not Creep Backward In “R” Position, AT-215, "
Vehicle Does Not Creep Backward In “R”
Position" .
❏ Vehicle Does Not Creep Forward In “D”, “2” Or “1” Position, AT- 2 1 8 , "
Vehicle Does Not Creep Forward
In “D”,“2” Or “1” Position" .