2007 INFINITI M35 ESP

DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTION
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Revision: 2007 April2007 M35/M45
DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTIONPFP:31940
DescriptionNCS001ON

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-II Reference ValueNCS001OO
On Board Diagnosis LogicNCS001OP

This is an OBD-II self-diagnostic item.

Diagnostic trouble code “P1774 LC/B SOLENOID FNCT” with CONSULT-II or 7th judgement flicker with-
out 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 CauseNCS001OQ

Harness or connectors
(Solenoid and switch circuits are open or shorted.)

Low coast brake solenoid valve

ATF pressure switch 2
DTC Confirmation ProcedureNCS001OR
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.
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 “A/T” with CONSULT-
II. If DTC (P1774) is detected, go to AT- 1 6 6 , "
Diagnostic Proce-
dure" .
If DTC (P1772) is detected, go to AT- 1 6 4 , "
Diagnostic 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 1
.ON
Low coast brake disengaged. Refer to AT- 2 1
.OFF
ATF PRES SW 2Low coast brake engaged. Refer to AT- 2 1
.ON
Low coast brake disengaged. Refer to AT- 2 1
.OFF
BCIA0030E

ATC-18
PREPARATION
Revision: 2007 April2007 M35/M45
(J-43926)
Refrigerant dye leak detection kit
Kit includes:
(J-42220)
UV lamp and UV safety goggles
(J-41459)
HFC-134a (R-134a) dye injector
Use with J-41447, 1/4 ounce
bottle
(J-41447)
HFC-134a (R-134a) fluorescent
leak detection dye
(Box of 24, 1/4 ounce bottles)
(J-43872)
Refrigerant dye cleanerPower supply:
DC 12 V (Battery terminal)
(J-42220)
UV lamp and UV safety gogglesPower supply:
DC 12 V (Battery terminal)
For checking refrigerant leak when
fluorescent dye is installed in A/C
system
Includes:
UV lamp and UV safety goggles
(J-41447)
HFC-134a (R-134a) fluorescent
leak detection dye
(Box of 24, 1/4 ounce bottles)Application:
For HFC-134a (R-134a) PAG oil
Container:
1/4 ounce (7.4 cc) bottle
(Includes self-adhesive dye
identification labels for affixing to
vehicle after charging system with
dye.)
(J-41459)
HFC-134a (R-134a) dye injector
Use with J-41447, 1/4 ounce
bottleFor injecting 1/4 ounce of fluorescent
leak detection dye into A/C system
(J-43872)
Refrigerant dye cleanerFor cleaning dye spills
(J-39183)
Manifold gauge set (with hoses
and couplers)Identification:

The gauge face indicates HFC-134a
(R-134a).
Fitting size: Thread size

1/2″ -16 ACME Tool number
(Kent-Moore No.)
Tool nameDescription
ZHA200H
SHA438F
SHA439F
SHA440F
SHA441F
RJIA0196E

ATC-22
REFRIGERATION SYSTEM
Revision: 2007 April2007 M35/M45
DESCRIPTION
General
The variable compressor is a swash plate type that changes piston stroke in response to the required cooling
capacity.
The tilt of the swash plate allows the piston’s stroke to change so that refrigerant discharge continuously
change from approx. 0 to 171 cm
3 (0 to 10.4 cu in).
RJIA4209E

ATC-30
AIR CONDITIONER CONTROL
Revision: 2007 April2007 M35/M45
OPERATION
The unified meter and A/C amp. receives data from each of the sensors. The unified meter and A/C amp.
sends mode door, air mix door, upper ventilator door and intake door opening angle data to the mode door
motor LCU, air mix door motor LCU, upper ventilator door motor LCU and intake door motor LCU.
The mode door motor, air mix door motors, upper ventilator door motor and intake door motor read their
respective signals according to the address signal. Opening angle indication signals received from the unified
meter and A/C amp. and each of the motor position sensors is compared by the LCUs in each door motor with
the existing decision and opening angles. Subsequently, HOT/COLD, DEF/VENT, OPEN/SHUT and FRE/REC
operation is selected. The new selection data is returned to the unified meter and A/C amp.
TRANSMISSION DATA AND TRANSMISSION ORDER
Unified meter and A/C amp. data is transmitted consecutively to each of the door motors following the form
shown in figure below.
Start:
Initial compulsory signal is sent to each of the door motors.
Address:
Data sent from the unified meter and A/C amp. are selected according to data-based decisions made by the
mode door motor, air mix door motor, upper ventilator door motor and intake door motor.
If the addresses are identical, the opening angle data and error check signals are received by the door motor
LCUs. The LCUs then make the appropriate error decision. If the opening angle data have no error, door con-
trol begins.
If an error exists, the received data are rejected and corrected data received. Finally, door control is based
upon the corrected opening angle data.
Opening angle:
Data that shows the indicated door opening angle of each door motor.
Error Check:
In this procedure, transmitted and received data is checked for errors. Error data are then compiled. The error
check prevents corrupted data from being used by the mode door motor, the air mix door motor, the upper
ventilator door motor and the intake door motor. Error data can be related to the following symptoms.

Malfunction of electrical frequency

Poor electrical connections

Signal leakage from transmission lines

Signal level fluctuation
RJIA4018E

ATC-36
AIR CONDITIONER CONTROL
Revision: 2007 April2007 M35/M45
REAR TEMPERATURE CONTROL SWITCH

Increases or decreases the set temperature.

A temperature for the rear seat with respect to a set temperature for the front seat can be adjusted by
operating switch.

Rear temperature control switch allows to select a temperature every 0.5°C (1°F) in the 18°C (60°F) to
32°C (90°F) range.

When the DUAL switch is ON, temperature for the rear seat changes keeping the temperature difference
between two front seats. [e.g. When lowering the set temperature for the rear seat 1°C (2°F) by operating
rear control switch at a set temperature of 25°C (77°F) for the driver’s seat and 26°C (79°F) for the pas-
senger’s seat, the set temperature for the driver’s seat and passenger’s seat lower 1°C (2°F) and become
24°C (75°F) for the driver’s seat and 25°C (77°F) for the passenger’s seat.]
NOTE:
A set temperature for the rear seat is tied to a set temperature for the passenger’s seat. Therefore, a set
temperature for the rear seat changes in conjunction with a set temperature for the passenger’s seat
(When the set temperature of front seats are independent).
Fail-Safe FunctionNJS000G9

If a communication error exists between the unified meter and A/C amp.,and the AV control unit or NAVI
control unit and multifunction switch for 30 seconds or longer, air conditioner is controlled under the follow-
ing conditions:
Compressor : ON
Air outlet : AUTO
Air inlet : FRE (Fresh)
Blower fan speed : AUTO
Set temperature : Setting before communication error occurs
Display : OFF

TROUBLE DIAGNOSIS
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Revision: 2007 April2007 M35/M45
13. CHECK MALFUNCTIONING SENSOR AND DOOR MOTOR
Refer to the following chart for malfunctioning code No.
(If two or more sensors and door motors malfunction, corresponding code Nos. indicates 1 second each.)
(If two door motors malfunction, corresponding code Nos. indicates 0.5 second each.)
*1: Perform self-diagnosis STEP-2 under sunshine.
When performing indoors, aim a light (more than 60 W) at sunload sensor, otherwise code No. 25 will indicate
despite that sunload sensor is functioning properly.
*2: AT C - 11 2 , "
DIAGNOSIS PROCEDURE FOR AMBIENT SENSOR" .
*3: AT C - 11 6 , "
DIAGNOSIS PROCEDURE FOR IN-VEHICLE SENSOR" .
*4: ATC-121, "
DIAGNOSIS PROCEDURE FOR INTAKE SENSOR" .
*5: AT C - 11 8 , "
DIAGNOSIS PROCEDURE FOR SUNLOAD SENSOR" .
*6: AT C - 8 4 , "
DIAGNOSIS PROCEDURE FOR AIR MIX DOOR MOTOR PBR" .
>> INSPECTION END
Code No. Malfunctioning sensor and door motor (Including circuits) Reference page
21 / −21 Ambient sensor *2
22 / −22 In-vehicle sensor *3
24 / −24 Intake sensor *4
25 / −25
Sunload sensor
*1*5
26 / −26 Air mix door motor PBR (Driver side)
*6
27 / −27 Air mix door motor PBR (Passenger side)
SJIA1781E

ATC-62
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
14. CHECK MALFUNCTIONING DOOR MOTOR POSITION SWITCH
Door motor PBR is malfunctioning.
(If two or more door motors malfunction, corresponding code Nos. indicates 1 second each.)
*1: If mode door motor (driver and passenger side) harness connector is disconnected, the following display
pattern will appear.
31→32→33→34→Return to 31
*2: If upper ventilator door motor harness connector is disconnected, the following display pattern will appear.
35→36→Return to 35
*3: If intake door motor harness connector is disconnected, the following display pattern will appear.
37→38→39→Return to 37
*4: AT C - 7 8 , "
DIAGNOSIS PROCEDURE FOR MODE DOOR MOTOR" .
*5: AT C - 8 1 , "
DIAGNOSIS PROCEDURE FOR UPPER VENTILATOR DOOR MOTOR" .
*6: AT C - 8 7 , "
DIAGNOSIS PROCEDURE FOR INTAKE DOOR MOTOR" .
>> INSPECTION END
Code No. *1 *2 *3Door position Reference page
31 VENT (Driver side)
Mode door motor *4 32 DEF (Driver side)
33 VENT (Passenger side)
34 DEF (Passenger side)
35 UPPER VENT (Open)
Upper ventilator door
motor*5
36 UPPER VENT (Shut)
37 FRE
Intake door motor *6 38 20% FRE
39 REC
SJIA1782E

TROUBLE DIAGNOSIS
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Revision: 2007 April2007 M35/M45
SYSTEM DESCRIPTION
Component Parts
Mode door control system components are:

Unified meter and A/C amp.

Mode door motor (LCU)

A/C LAN system (PBR built-in mode door motor, upper ventilator door motor, air mix door motor and
intake door motor)

In-vehicle sensor

Ambient sensor

Sunload sensor

Intake sensor
System Operation
The unified meter and A/C amp. receives data from each of the sensors. The unified meter and A/C amp.
sends air mix door, mode door, upper ventilator door and intake door opening angle data to the air mix door
motor LCUs, mode door motor LCUs, upper ventilator door motor LCU and intake door motor LCU.
The air mix door motors, mode door motors, upper ventilator door motor and intake door motor read their
respective signals according to the address signal. Opening angle indication signals received from the unified
meter and A/C amp. and each of the motor position sensors are compared by the LCUs in each door motor
with the existing decision and opening angles. Subsequently, HOT/COLD, DEF/VENT, OPEN/SHUT and FRE/
REC operation is selected. The new selection data are returned to the unified meter and A/C amp.
*1ATC-37, "Discharge Air Flow"*2AT C - 6 5 , "Operational Check"*3ATC-121, "Intake Sensor Circuit"
*4ATC-57, "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 2 to 6.*5AT C - 11 2 , "
Ambient Sensor Circuit"*6AT C - 11 5 , "In-vehicle Sensor Circuit"
*7ATC-118, "Sunload Sensor Circuit"*8AT C - 8 2 , "Air Mix Door Motor Cir-
cuit"
*9AT C - 5 7 , "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 13.
*10ATC-71, "
DIAGNOSIS PROCE-
DURE FOR LAN CIRCUIT"
*11ATC-139, "MODE DOOR MOTOR"*12AT C - 4 1 , "SYMPTOM TABLE"
RJIA4056E