2001 INFINITI QX4 check engine

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

20. Vehicle Does Not Decelerate By Engine
Brake
NBAT0092SYMPTOM:
Vehicle does not decelerate by engine brake when shifting
from 2
2(12)to11.
1 CHECK SYMPTOM
Is ª6. Vehicle Does Not Creep Backward In ªRº Positionº OK?
YesorNo
Ye s©Go to ª15. Engine Speed Does Not Return To Idle (Light Braking D
4,D3)º, AT-250.
No©Go to ª6. Vehicle Does Not Creep Backward In ªRº Positionº, AT-227.
TROUBLE DIAGNOSES FOR SYMPTOMS
20. Vehicle Does Not Decelerate By Engine Brake
AT-256

DIAGNOSTIC PROCEDURE=NBAT0204S03NOTE:
The diagnostic procedure includes inspections for the overdrive
control and throttle position switch circuits.
1 INSPECTION START
Do you have CONSULT-II?
YesorNo
Yes (With CONSULT-II)©GO TO 2.
No (Without CONSULT-
II)©GO TO 3.
2 CHECK PNP SWITCH CIRCUIT (With CONSULT-II)
With CONSULT-II
1. Turn ignition switch to ªONº position.
(Do not start engine.)
2. Select ªTCM INPUT SIGNALSº in ªDATA MONITORº mode for ªA/Tº with CONSULT-II.
3. Read out ªPº, ªRº, ªNº, ªDº, ª2º and ª1º position switches moving selector lever to each position. Check the signal of the
selector lever position is indicated properly.
SAT643J
OK or NG
OK©GO TO 5.
NG©GO TO 4.
TROUBLE DIAGNOSES FOR SYMPTOMS
21. TCM Self-diagnosis Does Not Activate (PNP, Overdrive Control and Throttle Position Switches Circuit Checks) (Cont'd)
AT-258

3 CHECK PNP SWITCH CIRCUIT (Without CONSULT-II)
Without CONSULT-II
1. Turn ignition switch to ªONº position.
(Do not start engine.)
2. Check voltage between TCM terminals 26, 27, 34, 35, 36 and ground while moving selector lever through each posi-
tion.
MTBL0205
SAT517J
Does battery voltage exist (B) or non-existent (0)?
Ye s©GO TO 5.
No©GO TO 4.
4 DETECT MALFUNCTIONING ITEM
Check the following items:
IPNP switch
Refer to ªComponent Inspectionº, AT-263.
IHarness for short or open between ignition switch and PNP switch (Main harness)
IHarness for short or open between PNP switch and TCM (Main harness)
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
21. TCM Self-diagnosis Does Not Activate (PNP, Overdrive Control and Throttle Position Switches Circuit Checks) (Cont'd)
AT-259

5 CHECK OVERDRIVE CONTROL SWITCH CIRCUIT
With CONSULT-II
1. Turn ignition switch to ªONº position.
(Do not start engine.)
2. Select ªTCM INPUT SIGNALSº in ªDATA MONITORº mode for ªA/Tº with CONSULT-II.
3. Read out ªOVERDRIVE SWITCHº. Check the signal of the overdrive control switch is indicated properly.
(Overdrive control switch ªONº displayed on CONSULT-II means overdrive ªOFFº.)
SAT645J
Without CONSULT-II
1. Turn ignition switch to ªONº position.
(Do not start engine.)
2. Check voltage between TCM terminal 22 and ground when overdrive control switch is ªONº and ªOFFº.
Voltage:
Switch position ªONº:
Battery voltage
Switch position ªOFFº:
1V or less
SAT531J
OK or NG
OK (With CONSULT-II)©GO TO 7.
OK (Without CONSULT-
II)©GO TO 9.
NG©GO TO 6.
6 DETECT MALFUNCTIONING ITEM
Check the following items:
IOverdrive control switch
Refer to ªComponent Inspectionº, AT-263.
IHarness for short or open between TCM and overdrive control switch (Main harness)
IHarness for short or open of ground circuit for overdrive control switch (Main harness)
OK or NG
OK (With CONSULT-II)©GO TO 7.
OK (Without CONSULT-
II)©GO TO 9.
NG©Repair or replace damaged parts.
TROUBLE DIAGNOSES FOR SYMPTOMS
21. TCM Self-diagnosis Does Not Activate (PNP, Overdrive Control and Throttle Position Switches Circuit Checks) (Cont'd)
AT-260

7 CHECK THROTTLE POSITION SWITCH CIRCUIT (With CONSULT-II)
With CONSULT-II
1. Turn ignition switch to ªONº position.
(Do not start engine.)
2. Select ªTCM INPUT SIGNALSº in ªDATA MONITORº mode for ªA/Tº with CONSULT-II.
3. Apply vacuum to the throttle opener, then check the following. Refer to steps 1 and 2 of ªPreparationº, ªTCM SELF-
DIAGNOSTIC PROCEDURE (No Tools)º, AT-46.
4. Read out ªCLOSED THL/SWº and ªW/O THRL/P-SWº depressing and releasing accelerator pedal.
Check the signal of throttle position switch is indicated properly.
MTBL0011
SAT646J
OK or NG
OK©GO TO 10.
NG©GO TO 8.
8 DETECT MALFUNCTIONING ITEM
Check the following items:
IThrottle position switch
Refer to ªComponent Inspectionº, AT-264.
IHarness for short or open between ignition switch and throttle position switch (Main harness)
IHarness for short or open between throttle position switch and TCM (Main harness)
OK or NG
OK©GO TO 10.
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
21. TCM Self-diagnosis Does Not Activate (PNP, Overdrive Control and Throttle Position Switches Circuit Checks) (Cont'd)
AT-261

9 CHECK THROTTLE POSITION SWITCH CIRCUIT (Without CONSULT-II)
Without CONSULT-II
1. Turn ignition switch to ªONº position.
(Do not start engine.)
2. Check voltage between TCM terminals 16, 17 and ground while depressing, and releasing accelerator pedal slowly.
(after warming up engine)
[Refer to ªPreparationº, ªTCM SELF-DIAGNOSTIC PROCEDURE (No Tools)º, AT-46.]
MTBL0519
SAT526J
OK or NG
OK©GO TO 10.
NG©GO TO 8.
10 CHECK DTC
Perform Diagnostic procedure, AT-258.
OK or NG
OK©INSPECTION END
NG©GO TO 11.
11 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
OK©INSPECTION END
NG©Repair or replace damaged parts.
TROUBLE DIAGNOSES FOR SYMPTOMS
21. TCM Self-diagnosis Does Not Activate (PNP, Overdrive Control and Throttle Position Switches Circuit Checks) (Cont'd)
AT-262