AT-154
DTC P1772 LOW COAST BRAKE SOLENOID VALVE
Revision: 2006 November2007 350Z
Diagnostic ProcedureNCS0006T
1. CHECK INPUT SIGNAL
With CONSULT-III
1. Turn ignition switch ON.
2. Select “SELECTION FROM MENU” in “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
3. Start engine.
4. Read out the value of “ON OFF SOL” while driving.
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- 1 6 2 , "
MAIN POWER SUPPLY AND GROUND CIR-
CUIT" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3. DETECT MALFUNCTIONING ITEM
Check A/T assembly harness connector pin terminals for damage or loose connection with harness connector.
OK or NG
OK >> Replace control valve with TCM. Refer to AT- 2 1 5 , "Control Valve with TCM and A/T Fluid Temper-
ature Sensor 2" .
NG >> Repair or replace damaged parts.
4. CHECK DTC
Perform AT- 1 5 3 , "
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- 1 9
.ON
Low coast brake disengaged. Refer to AT- 1 9
.OFF
DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTION
AT-155
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Revision: 2006 November2007 350Z
DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTIONPFP:31940
DescriptionNCS0006U
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 mal-
function such as control valve sticking, improper solenoid valve operation.
CONSULT-III Reference ValueNCS0006V
On Board Diagnosis LogicNCS0006W
This is an OBD-II self-diagnostic item.
Diagnostic trouble code “P1774 LC/B SOLENOID FNCT” with CONSULT-III or 7th judgment flicker with-
out CONSULT-III 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 CauseNCS0006X
Harness or connectors
(The solenoid and switch circuits are open or shorted.)
Low coast brake solenoid valve
ATF pressure switch 2
DTC Confirmation ProcedureNCS0006Y
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-III
1. Start engine.
2. Accelerate vehicle to maintain the following conditions.
MANU MODE SW: ON
GEAR: “1” or “2” (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 “TRANSMISSION” with CONSULT-III.
If DTC (P1774) is detected, refer to AT- 1 5 6 , "
Diagnostic Procedure" .
If DTC (P1772) is detected, go to AT- 1 5 4 , "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-III”.
Item name Condition Display value
ON OFF SOLLow coast brake engaged. Refer to AT- 1 9
.ON
Low coast brake disengaged. Refer to AT- 1 9
.OFF
ATF PRES SW 2Low coast brake engaged. Refer to AT- 1 9
.ON
Low coast brake disengaged. Refer to AT- 1 9
.OFF
AT-156
DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTION
Revision: 2006 November2007 350Z
Diagnostic ProcedureNCS0006Z
1. CHECK INPUT SIGNALS
With CONSULT-III
1. Start engine.
2. Select “SELECTION FROM MENU” in “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
3. Drive vehicle in the manual mode (“1” or “2” 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- 1 6 2 , "
MAIN POWER SUPPLY AND GROUND CIR-
CUIT" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3. DETECT MALFUNCTIONING ITEM
Check A/T assembly harness connector pin terminals for damage or loose connection with harness connector.
OK or NG
OK >> Replace control valve with TCM. Refer to AT- 2 1 5 , "Control Valve with TCM and A/T Fluid Temper-
ature Sensor 2" .
NG >> Repair or replace damaged parts.
4. CHECK DTC
Perform AT- 1 5 5 , "
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- 1 9
.ON
Low coast brake disengaged. Refer to AT- 1 9
.OFF
ATF PRES SW 2Low coast brake engaged. Refer to AT- 1 9
.ON
Low coast brake disengaged. Refer to AT- 1 9
.OFF
AT-166
CLOSED THROTTLE POSITION AND WIDE OPEN THROTTLE POSITION CIR-
CUIT
Revision: 2006 November2007 350Z
CLOSED THROTTLE POSITION AND WIDE OPEN THROTTLE POSITION CIR-
CUIT
PFP:18002
CONSULT-III Reference ValueNCS0007Y
Diagnostic ProcedureNCS0007Z
1. CHECK CAN COMMUNICATION LINE
Perform self-diagnosis. Refer to AT- 8 6 , "
SELF-DIAGNOSTIC RESULT MODE" , AT- 9 2 , "TCM SELF-DIAG-
NOSTIC PROCEDURE (NO TOOLS)" .
Is a malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to AT- 9 4 , "DTC U1000 CAN COMMUNICATION LINE" .
NO >> GO TO 2.
2. CHECK THROTTLE POSITION SIGNAL CIRCUIT
With CONSULT-III
1. Turn ignition switch ON.
2. Select “ECU INPUT SIGNALS” in “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
3. Depress accelerator pedal and read out the value of “CLSD THL POS” and “W/O THL POS”.
OK or NG
OK >>INSPECTION END
NG >> Check the following. If NG, repair or replace damaged parts.
Perform self-diagnosis for “ENGINE” with CONSULT-III. Refer to EC-116, "CONSULT-III Func-
tion (ENGINE)" .
Open circuit or short to ground or short to power in harness or connectors.
Pin terminals for damage or loose connection with harness connector.
Item name Condition Display value
CLSD THL POSReleased accelerator pedal. ON
Fully depressed accelerator pedal. OFF
W/O THL POSFully depressed accelerator pedal. ON
Released accelerator pedal. OFF
Accelerator Pedal OperationMonitor Item
CLSD THL POS W/O THL POS
Released ON OFF
Fully depressed OFF ON
AT-168
A/T INDICATOR CIRCUIT
Revision: 2006 November2007 350Z
A/T INDICATOR CIRCUITPFP:24810
DescriptionNCS00082
The TCM sends the switch signals to unified meter and A/C amp. By CAN communication line. Then manual
mode switch position is indicated on the A/T position indicator.
CONSULT-III Reference ValueNCS00083
Diagnostic ProcedureNCS00084
1. CHECK INPUT SIGNALS
With CONSULT-III
1. Start engine.
2. Select “MAIN SIGNALS” in “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III and read
out the value of “GEAR”.
3. Drive vehicle in the manual mode, and confirm that the actual gear position and the meter's indication of
the position mutually coincide when the selector lever is shifted to the “+ (up)” or “- (down)” side (1st ⇔ 5th
gear).
OK or NG
OK >>INSPECTION END
NG >> Check the following.
A/T INDICATOR SYMPTOM CHART
Item name Condition Display value
GEAR During driving 1, 2, 3, 4, 5
Items Presumed Location of Trouble
The actual gear position does not change, or shifting into the
manual mode is not possible (no gear shifting in the manual mode
possible).
The A/T position indicator is not indicated.Manual mode switch
Refer to AT- 1 5 7 , "
DTC P1815 MANUAL MODE SWITCH" .
A/T main system (Fail-safe function actuated)
Refer to AT- 8 6 , "SELF-DIAGNOSTIC RESULT MODE" .
The actual gear position changes, but the A/T position indicator is
not indicated.Perform the self-diagnosis function.
Refer to AT- 8 6 , "SELF-DIAGNOSTIC RESULT MODE" .
The actual gear position and the indication on the A/T position
indicator do not coincide.Perform the self-diagnosis function.
Refer to AT- 8 6 , "SELF-DIAGNOSTIC RESULT MODE" .
Only a specific position or positions is/are not indicated on the A/T
position indicator.Check the unified meter and A/C amp.
Refer to DI-4, "COMBINATION METERS" .
TROUBLE DIAGNOSIS FOR SYMPTOMS
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Revision: 2006 November2007 350Z
Engine Cannot Be Started in “P” or “N” PositionNCS00087
SYMPTOM:
Engine cannot be started with selector lever in “P” or “N” position.
Engine can be started with selector lever in “D” or “R” position.
DIAGNOSTIC PROCEDURE
1. CHECK PNP SWITCH CIRCUIT
Perform self-diagnosis. Refer to AT- 8 6 , "
SELF-DIAGNOSTIC RESULT MODE" , AT- 9 2 , "Diagnostic Procedure
Without CONSULT-III" .
Do the self-diagnostic results indicate PNP switch?
YES >> Check the malfunctioning system. Refer to AT- 1 0 2 , "DTC P0705 PARK/NEUTRAL POSITION
SWITCH" .
NO >> GO TO 2.
2. CHECK A/T POSITION
Check A/T position. Refer to AT- 2 0 6 , "
Checking of A/T Position" .
OK or NG
OK >> GO TO 3.
NG >> Adjust A/T position. Refer to AT- 2 0 6 , "
Adjustment of A/T Position" .
3. CHECK STARTING SYSTEM
Check starting system. Refer to SC-8, "
STARTING SYSTEM" .
OK or NG
OK >>INSPECTION END
NG >> Repair or replace damaged parts.
In “P” Position, Vehicle Moves When PushedNCS00088
SYMPTOM:
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 A/T POSITION
Check A/T position. Refer to AT- 2 0 6 , "
Checking of A/T Position" .
OK or NG
OK >> GO TO 2.
NG >> Adjust A/T position. Refer to AT- 2 0 6 , "
Adjustment of A/T Position" .
2. CHECK PARKING COMPONENTS
Check parking components. Refer to AT- 2 2 7 , "
Parking Components" .
OK or NG
OK >>INSPECTION END
NG >> Repair or replace damaged parts.
TROUBLE DIAGNOSIS FOR SYMPTOMS
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Revision: 2006 November2007 350Z
Large Shock (“N” to “D” Position)NCS0008A
SYMPTOM:
A noticeable shock occurs when the selector lever is shifted from the “N” to “D” position.
DIAGNOSTIC PROCEDURE
1. CHECK SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis. Refer to AT- 8 6 , "
SELF-DIAGNOSTIC RESULT MODE" , AT- 9 2 , "Diagnostic Procedure
Without CONSULT-III" .
Is any malfunction detected by self-diagnostic results?
YES >> Check the malfunctioning system. Refer to AT- 8 6 , "SELF-DIAGNOSTIC RESULT MODE" , AT- 9 3 ,
"Judgment Self-diagnosis Code" .
NO >> GO TO 2.
2. ENGINE IDLE SPEED
Check engine idle speed. Refer to EC-76, "
Idle Speed and Ignition Timing Check" .
OK or NG
OK >> GO TO 3.
NG >> Adjust engine idle speed. Refer to EC-76, "
Idle Speed and Ignition Timing Check" .
3. CHECK A/T POSITION
Check A/T position. Refer to AT- 2 0 6 , "
Checking of A/T Position" .
OK or NG
OK >> GO TO 4.
NG >> Adjust A/T position. Refer to AT- 2 0 6 , "
Adjustment of A/T Position" .
4. CHECK A/T FLUID LEVEL
Check A/T fluid level. Refer to AT- 1 2 , "
Checking A/T Fluid" .
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- 5 0 , "
LINE PRESSURE TEST" .
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- 2 1 5 , "
Control Valve with TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT- 2 5 5 , "
DISASSEMBLY" .
3. Check the following.
–Oil pump assembly. Refer to AT- 2 7 1 , "Oil Pump" .
OK or NG
OK >> GO TO 8.
NG >> Repair or replace damaged parts.
TROUBLE DIAGNOSIS FOR SYMPTOMS
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Revision: 2006 November2007 350Z
Vehicle Does Not Creep Backward in “R” PositionNCS0008B
SYMPTOM:
The vehicle does not creep in the “R” position. Or an extreme lack of acceleration is observed.
DIAGNOSTIC PROCEDURE
1. CHECK SELF-DIAGNOSTIC RESULTS
Perform self-diagnosis. Refer to AT- 8 6 , "
SELF-DIAGNOSTIC RESULT MODE" , AT- 9 2 , "Diagnostic Procedure
Without CONSULT-III" .
Is any malfunction detected by self-diagnostic results?
YES >> Check the malfunctioning system. Refer to AT- 8 6 , "SELF-DIAGNOSTIC RESULT MODE" , AT- 9 3 ,
"Judgment Self-diagnosis Code" .
NO >> GO TO 2.
2. CHECK A/T POSITION
Check A/T position. Refer to AT- 2 0 6 , "
Checking of A/T Position" .
OK or NG
OK >> GO TO 3.
NG >> Adjust A/T position. Refer to AT- 2 0 6 , "
Adjustment of A/T Position" .
3. CHECK A/T FLUID LEVEL
Check A/T fluid level. Refer to AT- 1 2 , "
Checking A/T Fluid" .
OK or NG
OK >> GO TO 4.
NG >> Refill ATF.
4. CHECK STALL TEST
Check stall revolution with selector lever in “M” and “R” positions.
Refer to AT- 4 9 , "
STALL TEST" .
OK or NG
OK >> GO TO 6.
OK in “M” position, NG in “R” position>>GO TO 5.
NG in both “M” and “R” positions>>GO TO 8.
5. DETECT MALFUNCTIONING ITEM
1. Disassemble A/T. Refer to AT- 2 5 5 , "
DISASSEMBLY" .
2. Check the following.
–Reverse brake. Refer to AT- 2 5 5 , "Disassembly" .
OK or NG
OK >> GO TO 9.
NG >> Repair or replace damaged parts.
6. CHECK LINE PRESSURE
Check line pressure with the engine idling. Refer to AT- 5 0 , "
LINE PRESSURE TEST" .
OK or NG
OK >> GO TO 9.
NG - 1 >> Line pressure high. GO TO 7.
NG - 2 >> Line pressure low. GO TO 8.