Infiniti M45 (Y34). Manual — part 40

TROUBLE DIAGNOSIS

AT-45

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How To Perform Trouble Diagnosis For Quick and Accurate Repair

ACS004HN

INTRODUCTION

The TCM receives a signal from the vehicle speed sensor, accelerator pedal position 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 OBD-related parts of the
A/T system for malfunction-diagnostic purposes. The TCM is capa-
ble of diagnosing malfunctioning parts while the ECM can store mal-
functions 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 an error that occurs intermit-
tently rather than continuously. Most intermittent errors are caused
by poor electric connections or improper wiring. In this case, careful
checking of suspected circuits may help prevent the replacement of
good parts.
A visual check only may not find the cause of the errors. A road test
with CONSULT-II (or GST) or a circuit tester connected should be
performed. Follow the

AT-46, "WORK FLOW"

.

Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such errors, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A “DIAGNOSTIC WORKSHEET” as
shown on the example (Refer to

AT-47

) should be used.

Start your diagnosis by looking for “conventional” errors first. This will
help troubleshoot driveability errors on an electronically controlled
engine vehicle.
Also check related Service bulletins.

SAT631IB

SAT632I

SEF234G

AT-46

TROUBLE DIAGNOSIS

WORK FLOW

A good understanding of the malfunction conditions can make troubleshooting faster and more accurate.
In general, each customer feels differently about a malfunction. It is important to fully understand the symp-
toms or conditions for a customer's complaint.
Make good use of the two sheets provided, “Information From Customer” (Refer to

AT-47

) and “Diagnostic

Worksheet” (Refer to

AT-47

), to perform the best troubleshooting possible.

Work Flow Chart

*1.

AT-47

*2.

AT-47

*3.

AT-43

*4.

AT-52

*5.

AT-52

,

AT-53

*6.

AT-55

*7.

AT-89

*8.

AT-39

*9.

AT-101

*10.

AT-103

*11.

AT-250

*12.

AT-254

*13.

AT-302

*14.

AT-63

*15.

AT-40

*16.

AT-103

*17.

AT-246

*18.

EC-50

SCIA0501E

TROUBLE DIAGNOSIS

AT-47

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DIAGNOSTIC WORKSHEET
Information From Customer

KEY POINTS

●

WHAT. . Vehicle & A/T model

●

WHEN. . Date, Frequencies

●

WHERE. . Road conditions

●

HOW. . Operating conditions, Symptoms

Diagnostic Worksheet Chart

Customer name

MR/MS

Model & Year

VIN

Trans. Model

Engine

Mileage

Incident Date

Manuf. Date

In Service Date

Frequency

❏

Continuous

❏

Intermittent (

times a day)

Symptoms

❏

Vehicle does not move.

(

❏

Any position

❏

Particular position)

❏

No up-shift

(

❏

1st

→

2nd

❏

2nd

→

3rd

❏

3rd

→

4th

❏

4th

→

5th)

❏

No down-shift

(

❏

5th

→

4th

❏

4th

→

3rd

❏

3rd

→

2nd

❏

2nd

→

1st)

❏

Lock-up malfunction

❏

Shift point too high or too low.

❏

Shift shock or slip

(

❏

N

→

D

❏

Lock-up

❏

Any drive position)

❏

Noise or vibration

❏

No kick down

❏

No pattern select

❏

Others

(

)

A/T CHECK indicator lamp

Blinks for about 8 seconds.

❏

Continuously lit

❏

Not lit

Malfunction indicator lamp (MIL)

❏

Continuously lit

❏

Not lit

1

❏

Read the item on cautions concerning fail-safe and understand the customer's complaint.

AT-43

2

❏

A/T fluid inspection

AT-52

❏

Leak (Repair leak location.)

❏

State

❏

Amount

3

❏

Stall test and line pressure test

AT-52

,

AT-53

❏

Stall test

❏

Torque converter one-way clutch

❏

Front brake

❏

High and low reverse clutch

❏

Low coast brake

❏

Forward brake

❏

Reverse brake

❏

Forward one-way clutch

❏

1st one-way clutch

❏

3rd one-way clutch

❏

Engine

❏

Line pressure low

❏

Except for input clutch and direct

clutch, clutches and brakes OK

❏

Line pressure inspection - Suspected part:

AT-48

TROUBLE DIAGNOSIS

4

❏

Perform all road tests and enter checks in required inspection items.

AT-55

4-1.

Check before engine is started

AT-56

❏

A/T CHECK Indicator Lamp Does Come On.

AT-256

.

❏

Perform self-diagnostics. Enter checks for detected items.

❏

Vehicle speed sensor·A/T.

AT-116

.

❏

Vehicle speed sensor·MTR.

AT-165

.

❏

Direct clutch solenoid valve.

AT-199

.

❏

TCC solenoid valve.

AT-123

.

❏

Line pressure solenoid valve.

AT-134

.

❏

Input clutch solenoid valve.

AT-179

.

❏

Front brake solenoid valve.

AT-189

.

❏

Low coast brake solenoid valve.

AT-220

.

❏

High and low reverse clutch solenoid valve.

AT-209

.

❏

PNP switch.

AT-110

.

❏

A/T fluid temperature sensors 1, 2.

AT-154

.

❏

Turbine revolution sensors 1, 2.

AT-160

.

❏

A/T interlock.

AT-167

.

❏

A/T 1st engine braking.

AT-174

.

❏

Start signal.

AT-106

.

❏

Accelerator pedal position signal.

AT-152

.

❏

Engine speed signal.

AT-121

.

❏

CAN communication.

AT-103

.

❏

TCM power supply.

AT-140

.

❏

Battery

❏

Other

4-2.

Check at idle

AT-56

❏

Engine Cannot Be Started in “P” and “N” Position.

AT-258

.

❏

In “P” Position, Vehicle Moves When Pushed.

AT-259

.

❏

In “N” Position Vehicle Moves.

AT-260

.

❏

Large Shock (“N” to “D” Position).

AT-262

.

❏

Vehicle Does Not Creep Backward In “R” Position.

AT-265

.

❏

Vehicle does Not Creep Forward In “D” Position.

AT-268

.

4-3.

Cruise test

AT-58

Part 1

❏

Vehicle Cannot Be Started From D1.

AT-271

.

❏

A/T Does Not Shift: D1

→

D2.

AT-274

.

❏

A/T Does Not Shift: D2

→

D3.

AT-277

.

❏

A/T Does Not Shift: D3

→

D4.

AT-280

.

❏

A/T Does Not Shift: D4

→

D5.

AT-283

.

❏

A/T Does Not Perform Lock-up.

AT-286

❏

A/T Does Not Hold Lock-up Condition.

AT-288

.

❏

Lock-up Is Not Released.

AT-290

.

❏

Engine Speed Does Not Return To Idle.

AT-291

.