2005 INFINITI FX35 check engine

ATC-96
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
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. Pressure is reduced 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.

Plates are sometimes cov-
ered 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

ATC-100
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
Insufficient HeatingAJS00150
SYMPTOM: Insufficient heating
INSPECTION FLOW
*1ATC-61, "Operational Check"*2AT C - 7 3 , "Air Mix Door Motor Circuit"*3ATC-54, "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 4 to
6.
*4 ATC-54, "
FUNCTION CONFIRMA-
TION PROCEDURE", see No. 13. *5
AT C - 6 6 , "
LAN System Circuit"*6ATC-79, "Blower Motor Circuit"
*7 EC-208, "DTC P0117, P0118 ECT
SENSOR" (VQ35DE) or EC-914,
"DTC P0117, P0118 ECT SEN-
SOR" (VK45DE) *8
CO-11, "
Changing Engine Coolant"
(VQ35DE) or CO-37, "
Changing
Engine Coolant" (VK45DE) *9
CO-15, "
Checking Radiator Cap"
(VQ35DE) or CO-43, "
Checking
Radiator Cap" (VK45DE)
RJIA2013E

ATC-104
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
Ambient Sensor CircuitAJS00154
COMPONENT DESCRIPTION
Ambient Sensor
The ambient sensor is attached on the hood lock stay. It detects
ambient temperature and converts it into a resistance 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 (0.6 °F) 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 grille 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 E34 terminal 1 (Y) and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
RJIA2016E
RJIA1461E
1 – Ground : Approx. 5 V
RJIA2017E

ATC-128
HEATER & COOLING UNIT ASSEMBLY
Revision: 2005 July 2005 FX

When recharging refrigerant, check for leaks.
NOTE:

When filling radiator with coolant, refer to CO-11, "Changing Engine Coolant" (VQ35DE) or CO-37,
"Changing Engine Coolant" (VK45DE).

Recharge the refrigerant.
Heater & cooling unit mounting bolt
Tightening torque : 6.8 N·m (0.69 kg-m, 60 in-lb)
Steering member mounting nut and bolt
Tightening torque : 12 N·m (1.2 kg-m, 9 fl-lb)

ATC-150
REFRIGERANT LINES
Revision: 2005 July 2005 FX
INSTALLATION
Installation is basically the reverse order of removal.
CAUTION:

Replace O-rings of high-pressure flexible hose with new ones, and then apply compressor oil to it
when installing it.

Connection point for female-side piping is thin. So, when inserting male-side piping, take care not
to deform female-side piping. Slowly insert in axial direction.

Insert one-touch joint connection point securely until it clicks.

After piping has been connected, pull male-side piping by hand to make sure piping does not
come off.

When recharging refrigerant, check for leaks.
Removal and Installation of Low-Pressure Pipe 1 (Engine Compartment)AJS0015V
REMOVAL
1. Use a refrigerant collecting equipment (for HFC-134a) to discharge the refrigerant.
2. Remove cowl top cover. Refer to EI-23, "
COWL TOP" .
3. Remove mounting bolt from low-pressure pipe 1 bracket and low-pressure flexible hose bracket.
4. Disconnect one-touch joints.
a. Set a disconnector (SST: 9253089916) on A/C piping.
b. Slide a disconnector toward vehicle front until it clicks.
c. Slide A/C piping toward vehicle front and disconnect it.
RJIA2067E
High-pressure flexible hose bracket mounting bolt
Tightening torque : 5.5 N·m (0.56 kg-m, 49 in-lb)
RJIA2068E
RJIA2069E

REFRIGERANT LINES ATC-151
C
D E
F
G H
I
K L
M A
B
AT C
Revision: 2005 July 2005 FX
5. Remove low-pressure pipe 1.
CAUTION:
Cap or wrap the joint of the pipe with suitable material such
as vinyl tape to avoid the entry of air.
INSTALLATION
Installation is basically the reverse order of removal.
CAUTION:

Replace O-rings of low-pressure pipe 1 with new ones, and then apply compressor oil to it when
installing it.

Connection point for female-side piping is thin. So, when inserting male-side piping, take care not
to deform female-side piping. Slowly insert in axial direction.

Insert one-touch joint connection point securely until it clicks.

After piping has been connected, pull male-side piping by hand to make sure piping does not
come off.

When recharging refrigerant, check for leaks.
Removal and Installation of High-Pressure Pipe 1 and 2 (Engine Compartment)AJS001BH
REMOVAL
1. Remove low-pressure pipe 1. Refer to ATC-150, "Removal and Installation of Low-Pressure Pipe 1
(Engine Compartment)" .
2. Remove high-pressure flexible hose and low-pressure flexible hose. Refer to ATC-149, "
Removal and
Installation of High-Pressure Flexible Hose" and ATC-148, "Removal and Installation of Low-Pressure
Flexible Hose" .
3. Remove high-pressure pipe 1 and 2 from clips.
4. Disconnect one-touch joint between condenser and high-pres- sure pipe 1.
a. Set a disconnector (SST: 9253089908) on A/C piping.
b. Slide a disconnector upward until it clicks.
c. Slide A/C piping upward 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.
RJIA2037E
Low-pressure pipe 1 bracket and low-pressure flexible hose bracket mounting bolts
Tightening torque : 5.5 N·m (0.56 kg-m, 49 in-lb)
RJIA2070E
RJIA2071E

ATC-158
REFRIGERANT LINES
Revision: 2005 July 2005 FX
Checking for Refrigerant LeaksAJS00163
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 electronic refrigerant leak detector or fluorescent
dye leak detector (SST: J-42220).
If dye is observed, confirm the leak with an electronic refrigerant 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 electronic 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 electronic 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 DetectorAJS00164
1. Check A/C system for leaks using the UV lamp and safety goggles (SST: J42220) 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: J43872) to prevent future mis- diagnosis.
4. Perform a system performance check and verify the leak repair with an approved electronic refrigerant 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 InjectionAJS00165
(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 fitting.
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 fitting. 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-160
REFRIGERANT LINES
Revision: 2005 July 2005 FX
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 to the A/C service ports.
3. Check if the A/C refrigerant pressure is at least 345 kPa (3.52 kg/cm
2 , 50 psi) above 16 °C (61 °F). If less
than specification, recover/evacuate and recharge the system with the specified amount of refrigerant.
NOTE:
At temperatures below 16 °C (61 °F), 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 o (VK45DE) or n (VQ35DE)]. Refer to ATC-140,
"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, refrigerant pressure sensor.
Liquid tank
Check the refrigerant connection.
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 engine.
8. Set the heater A/C control as follows;
a. A/C switch: ON
b. Mode door position: VENT (Ventilation)
c. Intake 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 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.
SHA839E