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Infiniti I35 (A33). Manual - part 33

CHECK INPUT SIGNAL (Without CONSULT-II)

Without CONSULT-II

1. Start engine.
2. Check voltage between TCM harness connector F50 terminal 39 (W/G) and ground.

SAT520JD

Voltage:

Refer to EC-137, “ECM INSPECTION TABLE”.

OK or NG

GO TO 5.

GO TO 3.

CHECK DTC

Perform Diagnostic Trouble Code (DTC) confirmation procedure, AT-126.

OK or NG

INSPECTION END

GO TO 6.

CHECK TCM INSPECTION

1. Perform TCM input/output signal inspection.
2. If NG, recheck TCM pin terminals for damage or loose connection with harness connector.

OK or NG

INSPECTION END

Repair or replace damaged parts.

IDX

DTC P0725 ENGINE SPEED SIGNAL

Diagnostic Procedure (Cont’d)

AT-129

Description

NHAT0046

This malfunction will not be detected while the A/T CHECK
indicator lamp is indicating another self-diagnosis malfunction.

This malfunction is detected when the A/T does not shift into
first gear position as instructed by the TCM. This is not caused
by electrical malfunction (circuits open or shorted) but by
mechanical malfunction such as control valve sticking,
improper solenoid valve operation, etc.

Gear position

Shift solenoid valve A

ON (Closed)

OFF (Open)

ON (Closed)

Shift solenoid valve B

ON (Closed)

OFF (Open)

TCM TERMINALS AND REFERENCE VALUE

NHAT0046S01

Remarks: Specification data are reference values.

Terminal

No.

Wire color

Item

Condition

Judgement

standard

(Approx.)

R/Y

Shift solenoid
valve A

When shift solenoid valve A operates.
(When driving in D

or D

Battery volt-
age

When shift solenoid valve A does not operate.
(When driving in D

or D

LG/B

Shift solenoid
valve B

When shift solenoid valve B operates.
(When driving in D

or D

Battery volt-
age

When shift solenoid valve B does not operate.
(When driving in D

or D

On Board Diagnosis Logic

NHAT0213

This diagnosis monitors actual gear position by checking the torque
converter slip ratio calculated by TCM as follows:
Torque converter slip ratio = A x C/B
A: Output shaft revolution signal from revolution sensor
B: Engine speed signal from ECM
C: Gear ratio determined as gear position which TCM supposes
If the actual gear position is higher than the position (1st) supposed
by TCM, the slip ratio will be more than normal. In case the ratio
exceeds the specified value, TCM judges this diagnosis malfunc-
tion.
This malfunction will be caused when either shift solenoid valve A
is stuck open or shift solenoid valve B is stuck open.
Gear positions supposed by TCM are as follows.
In case of gear position with no malfunctions: 1, 2, 3 and 4 posi-
tions
In case of gear position with shift solenoid valve A stuck open: 2*,
2, 3 and 3 positions
In case of gear position with shift solenoid valve B stuck open: 4*,
3, 3 and 4 positions to each gear position above
*: P0731 is detected.
Diagnostic trouble code A/T 1ST GR FNCTN with CONSULT-II or
P0731 without CONSULT-II is detected when A/T cannot be shifted
to the 1st gear position even if electrical circuit is good.

DTC P0731 A/T 1ST GEAR FUNCTION

Description

AT-130

Possible Cause

NHAT0214

Check the following items.

Shift solenoid valve A

Shift solenoid valve B

Each clutch

Hydraulic control circuit

SAT014K

SAT860K

SAT021J

Diagnostic Trouble Code (DTC) Confirmation
Procedure

NHAT0215

CAUTION:

Always drive vehicle at a safe speed.

Be careful not to rev engine into the red zone on the
tachometer.

NOTE:
If “DTC Confirmation Procedure” has been previously conducted,
always turn ignition switch OFF and wait at least 10 seconds before
conducting the next test.
TESTING CONDITION:
Always drive vehicle on a level road to improve the accuracy
of test.
After the repair, perform the following procedure to confirm the
malfunction is eliminated.

WITH CONSULT-II

NHAT0215S01

Start engine and select “DATA MONITOR” mode for “A/T” with
CONSULT-II.

Make sure that output voltage of A/T fluid temperature sensor
is within the range below.
FLUID TEMP SEN: 0.4 - 1.5V
If out of range, drive the vehicle to decrease the voltage (warm
up the fluid) or stop engine to increase the voltage (cool down
the fluid).

Select “1ST GR FNCTN P0731” of “DTC WORK SUPPORT”
mode for “A/T” with CONSULT-II and touch “START”.

Accelerate vehicle to 20 to 25 km/h (12 to 16 MPH) under the
following condition and release the accelerator pedal com-
pletely.
THROTTLE POSI: Less than 1.0/8 (at all times during step
4)
Selector lever: D position

Check that “GEAR” shows “2” after releasing pedal.

Depress accelerator pedal to WOT (more than 7.0/8 of
“THROTTLE POSI”) quickly from a speed of 20 to 25 km/h (12
to 16 MPH) until “TESTING” changes to “STOP VEHICLE” or
“COMPLETED”. (It will take approximately 3 seconds.)
If the check result NG appears on CONSULT-II screen, go to
“DIAGNOSTIC PROCEDURE”, AT-134.
If “STOP VEHICLE” appears on CONSULT-II screen, go to the
following step.

Check that “GEAR” shows “1” when depressing accelera-
tor pedal to WOT.

If “TESTING” does not appear on CONSULT-II for a long
time, select “SELF-DIAG RESULTS” for “ENGINE”. In case

IDX

DTC P0731 A/T 1ST GEAR FUNCTION

Possible Cause

AT-131

a 1st trip DTC other than P0731 is shown, refer to appli-
cable “TROUBLE DIAGNOSIS FOR DTC”.

Stop vehicle.

Follow the instruction displayed. (Check for normal shifting
referring to the table below.)

Vehicle condition

Gear on actual transmission shift pattern when

screen is changed to 1

No malfunction exists.

Malfunction for P0731 exists.

Make sure that “OK” is displayed. (If “NG” is displayed, refer
to “DIAGNOSTIC PROCEDURE”.)
Refer to AT-134, “DIAGNOSTIC PROCEDURE”.
Refer to AT-381, “Shift Schedule”.

WITH GST

NHAT0215S02

Follow the procedure “With CONSULT-II”.

DTC P0731 A/T 1ST GEAR FUNCTION

Diagnostic Trouble Code (DTC) Confirmation Procedure (Cont’d)

AT-132

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