sensor INFINITI QX56 2007 Factory Service Manual

AT-148
< SERVICE INFORMATION >
DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTION
DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTION
DescriptionINFOID:0000000003532408
• Low coast brake solenoid valve is turned “ON” or “OFF” by the TCM in response to signals sent from the
PNP switch, vehicle speed sensor and accelerator pedal position sensor (throttle position sensor). Gears will
then be shifted to the optimum position.
• This is not only caused by electrical malfunction (circuits open or shorted) but also by mechanical malfunc-
tion such as control valve sticking, improper solenoid valve operation.
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003532409
On Board Diagnosis LogicINFOID:0000000003532410
• This is an OBD-II self-diagnostic item.
• Diagnostic trouble code “P1774 LC/B SOLENOID FNCT” with CONSULT-II is detected under the following
conditions.
- When TCM detects that actual gear ratio is irregular, and relation between gear position and condition of
ATF pressure switch 2 is irregular during depressing accelerator pedal. (Other than during shift change)
- When TCM detects that relation between gear position and condition of ATF pressure switch 2 is irregular
during releasing accelerator pedal. (Other than during shift change)
Possible CauseINFOID:0000000003532411
• Harness or connectors
(The solenoid and switch circuits are open or shorted.)
• Low coast brake solenoid valve
• ATF pressure switch 2
DTC Confirmation ProcedureINFOID:0000000003532412
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If “DTC Confirmation Procedure” has been previously performed, always turn ignition switch “OFF”
and wait at least 10 seconds before performing the next test.
After the repair, perform the following procedure to confirm the malfunction is eliminated.
WITH CONSULT-II
1. Start engine.
2. Accelerate vehicle to maintain the following conditions.
Selector lever: “1” or “2” position
Gear position: “1st” or “2nd” gear (LC/B ON/OFF)
3. Perform step “2” again.
4. Turn ignition switch “OFF”, then perform step “1” to “3” again.
5. Check “SELF-DIAG RESULTS” mode for “A/T” with CONSULT-
II. If DTC (P1774) is detected, refer to AT-149, "
Diagnosis Pro-
cedure".
If DTC (P1772) is detected, go to AT-146, "
Diagnosis Proce-
dure".
WITH GST
Follow the procedure “With CONSULT-II”.
Item name Condition Display value
ON OFF SOLLow coast brake engaged. Refer to AT- 2 0
.ON
Low coast brake disengaged. Refer to AT- 2 0
.OFF
ATF PRES SW 2Low coast brake engaged. Refer to AT- 2 0
.ON
Low coast brake disengaged. Refer to AT- 2 0
.OFF
BCIA0031E

DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTION
AT-149
< SERVICE INFORMATION >
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Diagnosis ProcedureINFOID:0000000003532413
1.CHECK INPUT SIGNALS
With CONSULT-II
1. Start the engine.
2. Select “SELECTION FROM MENU” in “DATA MONITOR” mode
for “A/T” with CONSULT-II.
3. Drive vehicle in the “1” or “2” position (“1
1 ” or “22 ” gear) and
confirm the ON/OFF actuation of the “ATF PRES SW 2” and
“ON OFF SOL”.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2.CHECK TCM POWER SUPPLY AND GROUND CIRCUIT
Check TCM power supply and ground circuit. Refer to AT-158
.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3.DETECT MALFUNCTIONING ITEM
Check the following items:
• The A/T assembly harness connector pin terminals for damage or loose connection with harness connector.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT-210, "Control Valve with TCM and A/T Fluid Tem-
perature Sensor 2".
NG >> Repair or replace damaged parts.
4.CHECK DTC
Perform “DTC Confirmation Procedure”.
• Refer to AT-148, "
DTC Confirmation Procedure".
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
Item name Condition Display value
ON OFF SOLLow coast brake engaged. Refer to AT- 2 0
.ON
Low coast brake disengaged. Refer to AT- 2 0
.OFF
ATF PRES
SW 2Low coast brake engaged. Refer to AT- 2 0
.ON
Low coast brake disengaged. Refer to AT- 2 0
.OFF
SCIA4794E

DTC P1841 ATF PRESSURE SWITCH 1
AT-151
< SERVICE INFORMATION >
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1. Start engine.
2. Select “ECU INPUT SIGNALS” or “MAIN SIGNALS” in “DATA
MONITOR” mode for “A/T” with CONSULT-II.
3. Drive vehicle in the “D” position (3rd ⇒ 4th gear), and confirm
the ON/OFF actuation of the “ATF PRES SW 1”.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2.CHECK TCM POWER SUPPLY AND GROUND CIRCUIT
Check TCM power supply and ground circuit. Refer to AT-158
.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3.DETECT MALFUNCTIONING ITEM
Check the following items:
• The A/T assembly harness connector pin terminals for damage or loose connection with harness connector.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT-210, "Control Valve with TCM and A/T Fluid Tem-
perature Sensor 2".
NG >> Repair or replace damaged parts.
4.CHECK DTC
Perform “DTC Confirmation Procedure”.
• Refer to AT-150, "
DTC Confirmation Procedure".
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
Item name Condition Display value
ATF PRES
SW 1Front brake engaged. Refer to AT- 2 0
.ON
Front brake disengaged. Refer to AT- 2 0
.OFF
PCIA0067E

DTC P1843 ATF PRESSURE SWITCH 3
AT-153
< SERVICE INFORMATION >
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1. Start engine.
2. Select “ECU INPUT SIGNALS” or “MAIN SIGNALS” in “DATA
MONITOR” mode for “A/T” with CONSULT-II.
3. Drive vehicle in the “D” position (3rd ⇒ 4th gear), and confirm
the ON/OFF actuation of the “ATF PRES SW 3”.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2.CHECK TCM POWER SUPPLY AND GROUND CIRCUIT
Check TCM power supply and ground circuit. Refer to AT-158
.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3.DETECT MALFUNCTIONING ITEM
Check the following items:
• The A/T assembly harness connector pin terminals for damage or loose connection with harness connector.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT-210, "Control Valve with TCM and A/T Fluid Tem-
perature Sensor 2".
NG >> Repair or replace damaged parts.
4.CHECK DTC
Perform “DTC Confirmation Procedure”.
• Refer to AT-152, "
DTC Confirmation Procedure".
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
Item name Condition Display value
ATF PRES
SW 3Input clutch engaged. Refer to AT- 2 0
.ON
Input clutch disengaged. Refer to AT- 2 0
.OFF
PCIA0067E

DTC P1845 ATF PRESSURE SWITCH 5
AT-155
< SERVICE INFORMATION >
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1. Start engine.
2. Select “ECU INPUT SIGNALS” or “MAIN SIGNALS” in “DATA
MONITOR” mode for “A/T” with CONSULT-II.
3. Drive vehicle in the “D” position (1st ⇒ 2nd gear), and confirm
the ON/OFF actuation of the “ATF PRES SW 5”.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2.CHECK TCM POWER SUPPLY AND GROUND CIRCUIT
Check TCM power supply and ground circuit. Refer to AT-158
.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3.DETECT MALFUNCTIONING ITEM
Check the following items:
• The A/T assembly harness connector pin terminals for damage or loose connection with harness connector.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT-210, "Control Valve with TCM and A/T Fluid Tem-
perature Sensor 2".
NG >> Repair or replace damaged parts.
4.CHECK DTC
Perform “DTC Confirmation Procedure”.
• Refer to AT-154, "
DTC Confirmation Procedure"
.
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
Item name Condition Display value
ATF PRES
SW 5Direct clutch engaged. Refer to AT- 2 0
.ON
Direct clutch disengaged. Refer to AT- 2 0
.OFF
PCIA0067E

DTC P1846 ATF PRESSURE SWITCH 6
AT-157
< SERVICE INFORMATION >
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1. Start the engine.
2. Select “ECU INPUT SIGNALS” or “MAIN SIGNALS” in “DATA
MONITOR” mode for “A/T” with CONSULT-II.
3. Drive vehicle in the “D” position (2nd ⇒ 3rd gear), and confirm
the ON/OFF actuation of the “ATF PRES SW 6”.
OK or NG
OK >> GO TO 4.
NG >> GO TO 2.
2.CHECK TCM POWER SUPPLY AND GROUND CIRCUIT
Check TCM power supply and ground circuit. Refer to AT-158
.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3.DETECT MALFUNCTIONING ITEM
Check the following items:
• The A/T assembly harness connector pin terminals for damage or loose connection with harness connector.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT-210, "Control Valve with TCM and A/T Fluid Tem-
perature Sensor 2".
NG >> Repair or replace damaged parts.
4.CHECK DTC
Perform “DTC Confirmation Procedure”.
• Refer to AT-156, "
DTC Confirmation Procedure".
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
Item name Condition Display value
ATF PRES SW
6High and low reverse clutch engaged. Re-
fer to AT- 2 0
.ON
High and low reverse clutch disengaged.
Refer to AT- 2 0
.OFFPCIA0067E

AT-160
< SERVICE INFORMATION >
MAIN POWER SUPPLY AND GROUND CIRCUIT
Check the following items:
• The A/T assembly harness connector terminals for damage or loose connection with harness connector.
OK or NG
OK >> GO TO 6.
NG >> Repair or replace damaged parts.
6.PERFORM SELF-DIAGNOSIS
Perform self-diagnosis. Refer to AT-83, "
CONSULT-II Function (A/T)".
OK or NG
OK >>INSPECTION END
NG-1 >> Self-diagnosis does not activate: GO TO 7.
NG-2 >> DTC is displayed: Check the malfunctioning system. Refer to AT-83, "
CONSULT-II Function (A/
T)".
7.CHECK TERMINAL CORD ASSEMBLY
1. Remove control valve with TCM. Refer to AT-210, "
Control Valve with TCM and A/T Fluid Temperature
Sensor 2".
2. Disconnect A/T assembly harness connector and TCM connector.
3. Check continuity between A/T assembly harness connector ter-
minals and TCM connector terminals.
4. Check continuity between A/T assembly harness connector ter-
minals and TCM connector terminals.
5. If OK, check harness for short to ground and short to power.
OK or NG
OK >> Replace the control valve with TCM. Refer to AT-210, "Control Valve with TCM and A/T Fluid Tem-
perature Sensor 2".
NG >> Replace open circuit or short to ground and short to power in harness or connectors.
Item Connector Terminal Continuity
A/T assembly harness con-
nectorF9 1
Ye s
TCM connector F502 9
A/T assembly harness con-
nectorF9 2
Ye s
TCM connector F502 10
A/T assembly harness con-
nectorF9 6
Ye s
TCM connector F502 4
SCIA5464E
Item Connector Terminal Continuity
A/T assembly harness con-
nectorF9 5
Ye s
TCM connector F504 21
A/T assembly harness con-
nectorF9 10
Ye s
TCM connector F504 22
SCIA5465E

TROUBLE DIAGNOSIS FOR SYMPTOMS
AT-169
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Even though the selector lever is set in the “P” position, the parking mechanism is not actuated,
allowing the vehicle to be moved when it is pushed.
DIAGNOSTIC PROCEDURE
1.CHECK PNP SWITCH CIRCUIT
Perform self-diagnosis. Refer to AT-83, "
CONSULT-II Function (A/T)".
Do the self-diagnosis results indicate PNP switch?
YES >> Check the malfunctioning system. Refer to AT- 9 9.
NO >> GO TO 2.
2.CHECK CONTROL CABLE
Check the control cable.
• Refer to AT-208, "
Checking of A/T Position".
OK or NG
OK >> GO TO 3.
NG >> Adjust control cable. Refer to AT-208, "
Adjustment of A/
T Position".
3.CHECK A/T FLUID CONDITION
1. Remove oil pan. Refer to AT-210, "
Control Valve with TCM and A/T Fluid Temperature Sensor 2".
2. Check A/T fluid condition. Refer to AT-13, "
Checking Automatic
Transmission Fluid (ATF)".
OK or NG
OK >>INSPECTION END
NG >> GO TO 4.
4.DETECT MALFUNCTIONING ITEM
• Check the malfunction items. If any items are damaged, repair or replace damaged parts. Refer to AT-60,
"Symptom Chart" (Symptom No.58).
OK or NG
OK >>INSPECTION END
NG >> Repair or replace damaged parts.
In "N" Position, Vehicle MovesINFOID:0000000003532451
SYMPTOM:
Vehicle moves forward or backward when selecting “N” position.
DIAGNOSTIC PROCEDURE
1.CHECK PNP SWITCH CIRCUIT
Perform self-diagnosis. Refer to AT-83, "
CONSULT-II Function (A/T)".
Do the self-diagnostic results indicate PNP switch?
YES >> Check the malfunctioning system. Refer to AT- 9 9.
NO >> GO TO 2.
2.CHECK CONTROL CABLE
LCIA0345E
SCIA5199E

AT-170
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYMPTOMS
Check the control cable.
• Refer to AT-208, "
Checking of A/T Position".
OK or NG
OK >> GO TO 3.
NG >> Adjust control cable. Refer to AT-208, "
Adjustment of A/
T Position".
3.CHECK A/T FLUID LEVEL
Check A/T fluid level. Refer to AT-13, "
Checking Automatic Trans-
mission Fluid (ATF)".
OK or NG
OK >> GO TO 4.
NG >> Refill ATF.
4.CHECK A/T FLUID CONDITION
1. Remove oil pan. Refer to AT-210, "
Control Valve with TCM and A/T Fluid Temperature Sensor 2".
2. Check A/T fluid condition. Refer to AT-13, "
Checking Automatic
Transmission Fluid (ATF)".
OK or NG
OK >> GO TO 5.
NG >> Check the malfunction items. If any items are damaged,
repair or replace damaged parts. Refer to AT-60, "
Symp-
tom Chart" (Symptom No.60).
5.CHECK SYMPTOM
Check again. Refer to AT-55, "
Check at Idle".
OK or NG
OK >>INSPECTION END
NG >> GO TO 6.
6.PERFORM TCM INSPECTION
1. Perform TCM input/output signals inspection. Refer to AT-82, "
TCM Input/Output Signal Reference
Va l u e".
2. If NG, recheck A/T assembly harness connector terminals for damage or loose connection with harness
connector.
OK or NG
OK >>INSPECTION END
NG >> Repair or replace damaged parts.
Large Shock ("N" to "D" Position)INFOID:0000000003532452
SYMPTOM:
A noticeable shock occurs when the selector lever is shifted from the “N” to “D” position.
LCIA0345E
SAT638A
SCIA5199E

TROUBLE DIAGNOSIS FOR SYMPTOMS
AT-171
< SERVICE INFORMATION >
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DIAGNOSTIC PROCEDURE
1.CHECK SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis. Refer to AT-83, "
CONSULT-II Function (A/T)".
Do the self-diagnostic results indicate A/T fluid temperature sensor, engine speed signal, accelerator pedal
position sensor, ATF pressure switch 1, front brake solenoid valve, CAN communication line?
YES >> Check the malfunctioning system. Refer to AT- 11 9, AT-109, AT- 11 7' AT-150' AT-134' AT- 9 1.
NO >> GO TO 2.
2.ENGINE IDLE SPEED
Check the engine idle speed. Refer to EC-75, "
Idle Speed and Ignition Timing Check".
OK or NG
OK >> GO TO 3.
NG >> Repair.
3.CHECK CONTROL CABLE
Check the control cable.
• Refer to AT-208, "
Checking of A/T Position".
OK or NG
OK >> GO TO 4.
NG >> Adjust control cable. Refer to AT-208, "
Adjustment of A/
T Position".
4.CHECK A/T FLUID LEVEL
Check the A/T fluid level. Refer to AT-13, "
Checking Automatic
Transmission Fluid (ATF)".
OK or NG
OK >> GO TO 5.
NG >> Refill ATF.
5.CHECK LINE PRESSURE
Check line pressure at idle with selector lever in “D” position. Refer
to AT-51, "
Inspections Before Trouble Diagnosis".
OK or NG
OK >> GO TO 8.
NG - 1 >> Line pressure high: GO TO 6.
NG - 2 >> Line pressure low: GO TO 7.
6.DETECT MALFUNCTIONING ITEM
1. Check control valve with TCM. Refer to AT-210, "
Control Valve with TCM and A/T Fluid Temperature Sen-
sor 2".
2. Disassemble A/T. Refer to AT-240, "
Disassembly".
3. Check the following items:
LCIA0345E
SAT638A
SAT494G