check engine INFINITI M35 2006 Factory Service Manual

TROUBLE DIAGNOSIS
ATC-97
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5. CHECK BCM INPUT (COMPRESSOR ON) SIGNAL
Check compressor ON/OFF signal. Refer to AT C - 4 0 , "
CONSULT-II
Function (ECM)" .
OK or NG
OK >> GO TO 8.
NG >> GO TO 6.
6. CHECK REFRIGERANT PRESSURE SENSOR
WITH CONSULT-II
1. Start the engine.
2. Check voltage of refrigerant pressure sensor. Refer to EC-149, "
CONSULT-II Reference Value in Data
Monitor" (VQ35DE) or EC-862, "CONSULT-II Reference Value in Data Monitor" (VK45DE).
WITHOUT CONSULT-II
1. Start the engine.
2. Check voltage between ECM harness connector F108 terminal
70 and ground.
OK or NG
OK >>WITH CONSULT-II: GO TO 7.
WITHOUT CONSULT-II: Repair harness or connector.
NG >> Refer to EC-692, "
REFRIGERANT PRESSURE SENSOR" (VQ35DE) or EC-1434, "REFRIGER-
ANT PRESSURE SENSOR" (VK45DE).
7. CHECK ECM INPUT (FAN ON) SIGNAL
Check FAN ON/OFF signal. Refer to AT C - 4 0 , "
CONSULT-II Function
(ECM)" .
OK or NG
OK >> GO TO 8.
NG >> Repair harness or connector.A/C SW ON : AIR COND SIG ON
A/C SW OFF : AIR COND SIG OFF
RJIA3646E
Terminals
Condition Voltage (+)
(
)
ECM
connectorTerminal
No.
F108 70 GroundA/C switch: ON
(Blower motor operates.)Approx. 1.0 -
4.0 V
PBIB1188E
FAN SW ON : HEATER FAN SW ON
FAN SW OFF : HEATER FAN SW OFF
RJIA3646E

TROUBLE DIAGNOSIS
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TROUBLE DIAGNOSIS FOR UNUSUAL PRESSURE
Whenever system’s high and/or low side pressure(s) is/are unusual, diagnose using a manifold gauge. The
marker above the gauge scale in the following tables indicates the standard (usual) pressure range. Since the
standard (usual) pressure, however, differs from vehicle to vehicle, refer to above table (Ambient air tempera-
ture-to-operating pressure table).
Both High- and Low-pressure Sides are Too High
High-pressure Side is Too High and Low-pressure Side is Too Low
Gauge indication Refrigerant cycle Probable cause Corrective action
Both high- and low-pressure sides
are too high.The pressure returns to nor-
mal soon after water is
splashed on condenser.Excessive refrigerant charge
in refrigeration cycle.Reduce refrigerant until speci-
fied pressure is obtained.
Air suction by cooling fan is
insufficient.Insufficient condenser cooling
performance.
1. Condenser fins are clogged.
2. Improper fan rotation of
cooling fan.
Clean condenser.
Check and repair cooling fan
as necessary.
Low-pressure pipe is not
cold.
When compressor is
stopped high-pressure
value quickly drops by
approximately 196 kPa (2
kg/cm
2 , 28 psi). It then
decreases gradually there-
after.Poor heat exchange in con-
denser
(After compressor operation
stops, high-pressure
decreases too slowly.).Air in refrigeration cycle.Evacuate repeatedly and
recharge system.
Engine tends to overheat.Engine cooling systems mal-
function.Check and repair each engine
cooling system.
An area of the low-pres-
sure pipe is colder than
areas near the evaporator
outlet.
Low-pressure pipe is
sometimes covered with
frost.
Excessive liquid refrigerant
on low-pressure side.
Excessive refrigerant dis-
charge flow.
Expansion valve is open a
little compared with the
specification.

Improper expansion valve
adjustment.Replace expansion valve.
AC359A
Gauge indication Refrigerant cycle Probable cause Corrective action
High-pressure side is too high and
low-pressure side is too low.
Upper side of condenser and
high-pressure side are hot,
however, liquid tank is not so
hot.High-pressure tube or parts
located between compressor
and condenser are clogged or
crushed.
Check and repair or replace
malfunctioning parts.
Check lubricant for contami-
nation.
AC360A

TROUBLE DIAGNOSIS
ATC-109
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Revision: 2006 January2006 M35/M45
Insufficient HeatingNJS000GW
SYMPTOM: Insufficient heating
INSPECTION FLOW
*1ATC-64, "Operational Check"*2ATC-83, "Air Mix Door Motor Circuit"*3AT C - 5 6 , "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 2 to
6.
*4ATC-56, "
FUNCTION CONFIRMA-
TION PROCEDURE", see No. 13.*5ATC-70, "
LAN System Circuit"*6AT C - 8 9 , "Blower Motor Circuit"
*7EC-226, "DTC P0117, P0118 ECT
SENSOR" (VQ35DE) or EC-948,
"DTC P0117, P0118 ECT SEN-
SOR" (VK45DE)*8CO-11, "
Changing Engine Coolant"
(VQ35DE) or CO-40, "
Changing
Engine Coolant" (VK45DE)*9CO-16, "
Checking Radiator Cap"
(VQ35DE) or CO-45, "
Checking
Radiator Cap" (VK45DE)
RJIA4084E

TROUBLE DIAGNOSIS
ATC-113
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Revision: 2006 January2006 M35/M45
Ambient Sensor CircuitNJS000H0
COMPONENT DESCRIPTION
Ambient Sensor
The ambient sensor is attached on the radiator core support (left
side). It detects ambient temperature and converts it into a resis-
tance value which is then input into the unified meter and A/C amp.
AMBIENT TEMPERATURE INPUT PROCESS
The unified meter and A/C amp. includes a processing circuit for the ambient sensor input. However, when the
temperature detected by the ambient sensor increases quickly, the processing circuit retards the unified meter
and A/C amp. function. It only allows the unified meter and A/C amp. to recognize an ambient temperature
increase of 0.33
C (0.6F) per 100 seconds.
As an example, consider stopping for a few minutes after high speed driving. Although the actual ambient tem-
perature has not changed, the temperature detected by the ambient sensor will increase. This is because the
heat from the engine compartment can radiate to the front bumper area, location of the ambient sensor.
DIAGNOSIS PROCEDURE FOR AMBIENT SENSOR
SYMPTOM: Ambient sensor circuit is open or shorted. (21 or 21 is
indicated on unified meter and A/C amp. as a result of performing
self-diagnosis STEP-2.)
1. CHECK VOLTAGE BETWEEN AMBIENT SENSOR AND GROUND
1. Disconnect ambient sensor connector.
2. Turn ignition switch ON.
3. Check voltage between ambient sensor harness connector E62
terminal 1 and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
RJIA4087E
RJIA4088E
1 – Ground : Approx. 5 V
RJIA2017E

HEATER & COOLING UNIT ASSEMBLY
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CAUTION:
Replace O-rings of A/C piping with new ones, and then apply compressor oil to it when installing
it.
Female-side piping connection is thin and easy to deform. Slowly insert the male-side piping
straight in axial direction.
Insert piping securely until a click is heard.
After piping connection is completed, pull male-side piping by hand to make sure that connection
does not come loose.
When recharging refrigerant, check for leaks.
NOTE:
When filling radiator with coolant, refer to CO-11, "Changing Engine Coolant" (VQ35DE) or CO-40,
"Changing Engine Coolant" (VK45DE).
Recharge the refrigerant.
Heater & cooling unit assembly mounting bolt
: 6.9 Nꞏm (0.7 kg-m, 61 in-lb)
Instrument stay mounting nut and bolt
: 12 Nꞏm (1.25 kg-m, 9 ft-lb)

REFRIGERANT LINES
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CAUTION:
Replace O-rings of low-pressure flexible hose and low-pressure pipe (VK45DE) with new ones,
and then apply compressor oil to it when installing it.
Female-side piping connection is thin and easy to deform. Slowly insert the male-side piping
straight in axial direction.
Insert piping securely until a click is heard.
After piping connection is completed, pull male-side piping by hand to make sure that connection
does not come loose.
When recharging refrigerant, check for leaks.
Removal and Installation of High-Pressure Flexible HoseNJS000HQ
REMOVAL
1. Use a refrigerant collecting equipment (for HFC-134a) to discharge the refrigerant.
2. Remove engine cover. Refer to EM-14, "
ENGINE ROOM COVER" (VQ35DE) or EM-173, "ENGINE
ROOM COVER" (VK45DE).
3. Remove air cleaner case and air duct. Refer to EM-17, "
AIR CLEANER AND AIR DUCT" (VQ35DE) or
EM-177, "
AIR CLEANER AND AIR DUCT" (VK45DE).
4. Remove mounting bolt from high-pressure flexible hose bracket.
5. Disconnect one-touch joint between high-pressure flexible hose
and condenser.
a. Set a disconnector (SST: 9253089912) on A/C piping.
b. Slide a disconnector backward until it clicks.
c. Slide A/C piping backward and disconnect it.
CAUTION:
Cap or wrap the joint of the pipe with suitable material such
as vinyl tape to avoid the entry of air.
6. Remove low-pressure pipe (VK45DE). Refer to ATC-158, "
Removal and Installation of Low-Pressure
Flexible Hose and Pipe" .
7. Remove mounting nut from high-pressure flexible hose, and
then remove high-pressure flexible hose.
CAUTION:
Cap or wrap the joint of the pipe with suitable material such
as vinyl tape to avoid the entry of air.Low-pressure flexible hose bracket mounting bolt
: 4.2 Nꞏm (0.43 kg-m, 37 in-lb)
RJIA4163E
RJIA4164E
RJIA4166E

ATC-160
REFRIGERANT LINES
Revision: 2006 January2006 M35/M45
INSTALLATION
Installation is basically the reverse order of removal.
CAUTION:
Replace O-rings of high-pressure flexible house with new ones, and then apply compressor oil to
it when installing it.
Female-side piping connection is thin and easy to deform. Slowly insert the male-side piping
straight in axial direction.
Insert piping securely until a click is heard.
After piping connection is completed, pull male-side piping by hand to make sure that connection
does not come loose.
When recharging refrigerant, check for leaks.
Removal and Installation of High-Pressure Pipe 1 (Engine Compartment)NJS000HR
REMOVAL
1. Remove low-pressure flexible hose. Refer to ATC-158, "Removal and Installation of Low-Pressure Flexi-
ble Hose and Pipe" .
2. Remove mounting bolt from high-pressure flexible hose bracket.
3. Remove high-pressure pipe 1 from vehicle clips.
4. Disconnect one-touch joints of high-pressure pipe 1.
a. Set a disconnector (SST: 9253089908) on A/C piping.
RJIA4165E
High-pressure flexible hose bracket mounting bolt
: 4.2 Nꞏm (0.43 kg-m, 37 in-lb)
RJIA4163E
RJIA4167E

REFRIGERANT LINES
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INSTALLATION
Install liquid tank, and then install liquid tank bracket on condenser.
CAUTION:
Make sure liquid tank bracket is securely installed at protru-
sion of condenser. (Make sure liquid tank bracket does not
move to a position below center of liquid tank.)
Replace O-rings of A/C piping with new ones, and then
apply compressor oil to it when installing it.
When recharging refrigerant, check for leaks.
Removal and Installation of CondenserNJS000HU
REMOVAL
1. Use a refrigerant collecting equipment (for HFC-134a) to discharge the refrigerant.
2. Remove engine cover. Refer to EM-14, "
ENGINE ROOM COVER" (VQ35DE) or EM-173, "ENGINE
ROOM COVER" (VK45DE).
3. Remove air cleaner case, air hose and air duct. Refer to EM-17, "
AIR CLEANER AND AIR DUCT"
(VQ35DE) or EM-177, "AIR CLEANER AND AIR DUCT" (VK45DE).
4. Remove engine under cover, using power tools.
5. Drain engine coolant. Refer to CO-11, "
Changing Engine Coolant" (VQ35DE) or CO-40, "Changing
Engine Coolant" (VK45DE).
6. Remove radiator fan shroud with cooling fan after (VK45DE). Refer to CO-51, "
COOLING FAN" .
7. Remove mounting clips and bolts, and then remove bracket.
8. Remove radiator upper mount, remove radiator and condenser
to the engine side.
9. Remove mounting bolt from high-pressure flexible hose bracket.
10. Remove high-pressure pipe1 from vehicle clip.
RJIA1441E
RJIA4173E
RJIA4174E

ATC-170
REFRIGERANT LINES
Revision: 2006 January2006 M35/M45
Checking for Refrigerant LeaksNJS000HY
Perform a visual inspection of all refrigeration parts, fittings, hoses and components for signs of A/C lubricant
leakage, damage and corrosion. A/C lubricant leakage may indicate an area of refrigerant leakage. Allow
extra inspection time in these areas when using either an electrical leak detector or fluorescent dye leak
detector (SST: J-42220).
If dye is observed, confirm the leak with an electrical leak detector. It is possible a prior leak was repaired and
not properly cleaned.
When searching for leaks, do not stop when one leak is found but continue to check for additional leaks at all
system components and connections.
When searching for refrigerant leaks using an electrical leak detector, move the probe along the suspected
leak area at 1 to 2 inches per second and no further than 1/4 inch from the component.
CAUTION:
Moving the electrical leak detector probe slower and closer to the suspected leak area will improve the
chances of finding a leak.
Checking System for Leaks Using the Fluorescent Leak DetectorNJS000HZ
1. Check A/C system for leaks using the UV lamp and safety goggles (SST: J-42220) in a low sunlight area
(area without windows preferable). Illuminate all components, fittings and lines. The dye will appear as a
bright green/yellow area at the point of leakage. Fluorescent dye observed at the evaporator drain open-
ing indicates an evaporator core assembly (tubes, core or expansion valve) leak.
2. If the suspected area is difficult to see, use an adjustable mirror or wipe the area with a clean shop rag or
cloth, with the UV lamp for dye residue.
3. After the leak is repaired, remove any residual dye using dye cleaner (SST: J-43872) to prevent future
misdiagnosis.
4. Perform a system performance check and verify the leak repair with an approved electrical leak detector.
NOTE:
Other gases in the work area or substances on the A/C components, for example, anti-freeze, windshield
washer fluid, solvents and lubricants, may falsely trigger the leak detector. Make sure the surfaces to be
checked are clean.
Clean with a dry cloth or blow off with shop air.
Do not allow the sensor tip of the detector to contact with any substance. This can also cause false readings
and may damage the detector.
Dye InjectionNJS000I0
(This procedure is only necessary when recharging the system or when the compressor has seized and was
replaced.)
1. Check A/C system static (at rest) pressure. Pressure must be at least 345 kPa (3.52 kg/cm
2 , 50 psi).
2. Pour one bottle (1/4 ounce / 7.4 cc) of the A/C refrigerant dye into the injector tool (SST: J-41459).
3. Connect the injector tool to the A/C low-pressure side service valve.
4. Start engine and switch A/C ON.
5. When the A/C operating (compressor running), inject one bottle (1/4 ounce / 7.4 cc) of fluorescent dye
through the low-pressure service valve using dye injector tool (SST: J-41459) (refer to the manufacture’s
operating instructions).
6. With the engine still running, disconnect the injector tool from the service valve.
CAUTION:
Be careful the A/C system or replacing a component, pour the dye directly into the open system
connection and proceed with the service procedures.
7. Operate the A/C system for a minimum of 20 minutes to mix the dye with the system oil. Depending on the
leak size, operating conditions and location of the leak, it may take from minutes to days for the dye to
penetrate a leak and become visible.
8. Attach a blue label as necessary.

ATC-172
REFRIGERANT LINES
Revision: 2006 January2006 M35/M45
CHECKING PROCEDURE
To prevent inaccurate or false readings, make sure there is no refrigerant vapor, shop chemicals, or cigarette
smoke in the vicinity of the vehicle. Perform the leak test in calm area (low air/wind movement) so that the
leaking refrigerant is not dispersed.
1. Stop engine.
2. Connect a suitable A/C manifold gauge set (SST: J-39183)to the A/C service valves.
3. Check if the A/C refrigerant pressure is at least 345 kPa (3.52 kg/cm
2 , 50 psi) above 16C (61F). If less
than specification, recover/evacuate and recharge the system with the specified amount of refrigerant.
NOTE:
At temperatures below 16
C (61F), leaks may not be detected since the system may not reach 345 kPa
(3.52 kg/cm
2 , 50 psi).
4. Perform the leak test from the high-pressure side (compressor discharge a to evaporator inlet h) to the
low-pressure side [evaporator drain hose i to shaft seal m(VQ35DE) or n(VK45DE)]. Refer to ATC-153,
"Components" . Perform a leak check for the following areas carefully. Clean the component to be
checked and move the leak detected probe completely around the connection/component.
Compressor
Check the fitting of high- and low-pressure flexible hoses, relief valve and shaft seal.
Condenser
Check the fitting of high-pressure flexible hose and pipe.
Liquid tank
Check the fitting of refrigerant pressure sensor.
Service valves
Check all around the service valves. Ensure service valve caps are secured on the service valves (to pre-
vent leaks).
NOTE:
After removing A/C manifold gauge set from service valves, wipe any residue from valves to prevent any
false readings by leak detector.
Cooling unit (Evaporator)
With engine OFF, turn blower fan on “High” for at least 15 seconds to dissipate any refrigerant trace in the
cooling unit. Wait a minimum of 10 minutes accumulation time (refer to the manufacturer’s recommended
procedure for actual wait time) before inserting the leak detector probe into the drain hose.
Keep the probe inserted for at least 10 seconds. Use caution not to contaminate the probe tip with water
or dirt that may be in the drain hose.
5. If a leak detector detects a leak, verify at least once by blowing compressed air into area of suspected
leak, then repeat check as outlined above.
6. Do not stop when one leak is found. Continue to check for additional leaks at all system components.
If no leaks are found, perform steps 7 - 10.
7. Start the engine.
8. Set the A/C control as follows;
a. A/C switch: ON
b. MODE door position: VENT (Ventilation)
c. Intake door position: Recirculation
d. Temperature setting: Max. cold
e. Fan speed: High
9. Run engine at 1,500 rpm for at least 2 minutes.
10. Stop the engine and perform leak check again following steps 4
through 6 above.
Refrigerant leaks should be checked immediately after stopping
the engine. Begin with the leak detector at the compressor. The
pressure on the high-pressure side will gradually drop after
refrigerant circulation stops and pressure on the low-pressure
side will gradually rise, as shown in the graph. Some leaks are
more easily detected when pressure is high.
11. Before connecting recovery/recycling recharging equipment to
vehicle, check recovery/recycling recharging equipment gauges.
SHA839E