2001 INFINITI QX4 Engine control

SAT341H
DescriptionNBAT0068The overrun clutch solenoid valve is activated by the TCM in
response to signals sent from the inhibitor switch, overdrive con-
trol switch, vehicle speed and throttle position sensors. The over-
run clutch operation will then be controlled.
TCM TERMINALS AND REFERENCE VALUENBAT0068S02Remarks: Specification data are reference values.
Terminal
No.Wire color Item ConditionJudgement
standard
(Approx.)
20 L/BOverrun clutch
solenoid valve
When overrun clutch solenoid valve operates.Battery volt-
age
When overrun clutch solenoid valve does not
operate.0V
ON BOARD DIAGNOSIS LOGICNBAT0068S03
Diagnostic trouble code Malfunction is detected when ... Check item (Possible cause)
: O/R CLTCH SOL/CIRCTCM detects an improper voltage drop
when it tries to operate the solenoid
valve.IHarness or connectors
(The solenoid circuit is open or shorted.)
IOverrun clutch solenoid valve
: P1760
SAT014K
SAT020K
DIAGNOSTIC TROUBLE CODE (DTC) CONFIRMATION
PROCEDURE
NBAT0068S01CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If ªDIAGNOSTIC TROUBLE CODE CONFIRMATION PROCE-
DUREº has been previously conducted, always turn ignition
switch ªOFFº and wait at least 5 seconds before conducting
the next test.
TESTING CONDITION:
Always drive vehicle on a level road to improve accuracy of
test.
After the repair, perform the following procedure to confirm the
malfunction is eliminated.
With CONSULT-II
1) Turn ignition switch ªONº and select ªDATA MONITORº mode
for ªENGINEº with CONSULT-II.
2) Start engine.
3) Accelerate vehicle to a speed of more than 10 km/h (6MPH)
in ªDº position (OD ªONº).
4) Release accelerator pedal completely in ªDº position (OD
ªOFFº).
GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P1760 OVERRUN CLUTCH SOLENOID VALVE
Description
AT-185

DescriptionNBAT0228The ECM and TCM provide mutual communication in relation to
engine output control signal (ignition timing retard signal) during
rapid standing starts/acceleration. With this consistent real-time
control, the shifting feel is substantially improved.
TCM TERMINALS AND REFERENCE VALUENBAT0228S01Remarks: Specification data are reference values.
Terminal
No.Wire color Item ConditionJudgement
standard
(Approx.)
33 G/R LAN
ÐÐ
*: This terminal is connected to the ECM.
ON BOARD DIAGNOSIS LOGICNBAT0228S02
Diagnostic trouble code Malfunction is detected when ... Check item (Possible cause)
: A/T COMM LINE
The ECM-A/T communication line is
open or shorted.IHarness or connector
: 12th judgement flicker
GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC A/T COMMUNICATION LINE
Description
AT-207

Diagnostic ProcedureNBAT0230
1 CHECK CIRCUIT BETWEEN TCM AND ECM
1. Turn ignition switch to OFF position.
2. Check continuity between TCM terminal 33 and ECM terminal 114.
SAT640JA
OK or NG
OK©GO TO 2.
NG©Repair or replace harness and connector between TCM and ECM.
2 CHECK DTC WITH ECM STEP 1
Perform self-diagnosis for engine control. Refer to EC-74, ªDESCRIPTIONº.
OK or NG
OK©GO TO 4.
NG©GO TO 3.
3 CHECK DTC WITH ECM STEP 2
Check ECM. Refer to EC-440 and EC-603, ªSystem Descriptionº and ªComponent Descriptionº.
OK or NG
OK©GO TO 4.
NG©Repair or replace damaged parts.
4 CHECK DTC
Perform Diagnostic Trouble Code (DTC) confirmation procedure, AT-208.
OK or NG
OK©INSPECTION END
NG©GO TO 5.
5 CHECK TCM INSPECTION
If NG, recheck TCM pin terminals for damage or loose connection with harness connector.
OK or NG
OK©INSPECTION END
NG©Repair or replace damaged parts.
DTC A/T COMMUNICATION LINE
Diagnostic Procedure
AT-210

SAT574J
DescriptionNBAT0207The TCM consists of a microcomputer and connectors for signal
input and output and for power supply. The unit controls the A/T.
ON BOARD DIAGNOSIS LOGICNBAT0207S01
Diagnostic trouble code Malfunction is detected when ... Check item (Possible cause)
: CONTROL UNIT (RAM)
: CONTROL UNIT (ROM)TCM memory (RAM) or (ROM) is mal-
functioning.TCM
SAT014K
SAT971J
DIAGNOSTIC TROUBLE CODE (DTC) CONFIRMATION
PROCEDURE
NBAT0207S02NOTE:
If ªDIAGNOSTIC TROUBLE CODE CONFIRMATION PROCE-
DUREº has been previously conducted, always turn ignition
switch ªOFFº and wait at least 5 seconds before conducting
the next test.
With CONSULT-II
1) Turn ignition switch ªONº and select ªDATA MONITORº mode
for A/T with CONSULT-II.
2) Start engine.
3) Run engine for at least 2 seconds at idle speed.
GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC CONTROL UNIT (RAM), CONTROL UNIT (ROM)
Description
AT-211

SAT574J
DescriptionNBAT0215The TCM consists of a microcomputer and connectors for signal
input and output and for power supply. The unit controls the A/T.
ON BOARD DIAGNOSIS LOGICNBAT0215S01
Diagnostic trouble code Malfunction is detected when ... Check item (Possible cause)
: CONT UNIT (EEP ROM)TCM memory (EEP ROM) is malfunc-
tioning.TCM
SAT014K
SAT971J
DIAGNOSTIC TROUBLE CODE (DTC) CONFIRMATION
PROCEDURE
NBAT0215S02NOTE:
If ªDIAGNOSTIC TROUBLE CODE CONFIRMATION PROCE-
DUREº has been previously conducted, always turn ignition
switch ªOFFº and wait at least 5 seconds before conducting
the next test.
With CONSULT-II
1) Turn ignition switch ªONº and select ªDATA MONITORº mode
for A/T with CONSULT-II.
2) Start engine.
3) Run engine for at least 2 seconds at idle speed.
GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC CONTROL UNIT (EEP ROM)
Description
AT-213

13. A/T Does Not Hold Lock-up Condition=NBAT0085SYMPTOM:
A/T does not hold lock-up condition for more than 30 seconds.
1 CHECK DIAGNOSTIC RESULTS
Does self-diagnosis show damage to engine speed signal circuit after cruise test?
SAT582I
YesorNo
Ye s©Check engine speed signal circuit. Refer to ªDTC P0725º, AT-116.
No©GO TO 2.
2 CHECK A/T FLUID CONDITION
1. Remove oil pan.
2. Check A/T fluid condition.
SAT171B
OK or NG
OK©GO TO 3.
NG©GO TO 5.
3 DETECT MALFUNCTIONING ITEM
1. Remove control valve assembly. Refer to AT-273.
2. Check the following items:
ITorque converter clutch control valve
IPilot valve
IPilot filter
OK or NG
OK©GO TO 4.
NG©Repair or replace damaged parts.
GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
TROUBLE DIAGNOSES FOR SYMPTOMS
13. A/T Does Not Hold Lock-up Condition
AT-247

15. Engine Speed Does Not Return To Idle
(Light Braking D
4®D3)=NBAT0087SYMPTOM:
IEngine speed does not smoothly return to idle when A/T
shifts from D
4to D3.
IVehicle does not decelerate by engine brake when turning
overdrive control switch OFF.
IVehicle does not decelerate by engine brake when shifting
A/T from ªDº to ª2º position.
1 CHECK SELF-DIAGNOSTIC RESULTS
Does self-diagnosis show damage to overrun clutch solenoid valve circuit after cruise test?
SAT583I
YesorNo
Ye s©Check overrun clutch solenoid valve circuit. Refer to ªDTC P1760º, AT-185.
No©GO TO 2.
2 CHECK THROTTLE POSITION SENSOR
Check throttle position sensor. Refer to EC-174, ªDescriptionº.
SAT142K
OK or NG
OK©GO TO 3.
NG©Repair or replace throttle position sensor.
TROUBLE DIAGNOSES FOR SYMPTOMS
15. Engine Speed Does Not Return To Idle (Light Braking D4®D3)
AT-250

3 CHECK A/T FLUID CONDITION
1. Remove oil pan.
2. Check A/T fluid condition.
SAT171B
OK or NG
OK©GO TO 4.
NG©GO TO 6.
4 DETECT MALFUNCTIONING ITEM
1. Remove control valve assembly. Refer to AT-273.
2. Check the following items:
IOverrun clutch control valve
IOverrun clutch reducing valve
IOverrun clutch solenoid valve
OK or NG
OK©GO TO 5.
NG©Repair or replace damaged parts.
5 CHECK SYMPTOM
Check again.
OK or NG
OK©INSPECTION END
NG©1. Perform TCM input/output signal inspection.
2. If NG, recheck TCM pin terminals for damage or loose connection with harness con-
nector.
6 DETECT MALFUNCTIONING ITEM
1. Remove control valve assembly. Refer to AT-273.
2. Check the following items:
IOverrun clutch control valve
IOverrun clutch reducing valve
IOverrun clutch solenoid valve
3. Disassemble A/T.
4. Check the following items:
IOverrun clutch assembly
IOil pump assembly
OK or NG
OK©GO TO 5.
NG©Repair or replace damaged parts.
GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
TROUBLE DIAGNOSES FOR SYMPTOMS
15. Engine Speed Does Not Return To Idle (Light Braking D4®D3) (Cont'd)
AT-251