Nissan Maxima. Manual — part 698

HA-18

< BASIC INSPECTION >

DIAGNOSIS AND REPAIR WORK FLOW

Accurate Repair

INFOID:0000000009465927

WORK FLOW

1.

LISTEN TO CUSTOMER COMPLAINT

Interview the customer to obtain as much information as possible about the conditions and environment under

which the symptom occurs.

>> GO TO 2.

2.

CHECK FOR SERVICE BULLETINS

Check for any service bulletins.

>> GO TO 3.

3.

CHECK FOR HVAC DTCS WITH CONSULT

Using CONSULT, perform “SELF-DIAGNOSIS RESULTS” of HVAC. Refer to

HAC-171, "DTC Index"

.

Are there any HVAC DTCs present?

YES

>> Go to HVAC DTC index. Refer to

HAC-171, "DTC Index"

.

NO

>> GO TO 4.

4.

PERFORM OPERATIONAL CHECK

Verify the symptom with operational check based on the information obtained from the customer. Refer to

HAC-108, "Operational Check"

.

>> GO TO 5.

5.

GO TO APPROPRIATE TROUBLE DIAGNOSIS

Go to appropriate trouble diagnosis. Refer to

HA-25, "WITH MONOCHROME DISPLAY : Symptom Matrix

Chart"

.

NOTE:

If DTC is displayed, erase DTC after repairing or replacing malfunctioning parts.
Is the inspection result normal?

YES

>> Repair or replace malfunctioning parts.

NO

>> GO TO 6.

6.

FINAL CHECK

Check that the A/C system operates normally.
Is the inspection result normal?

YES

>> Inspection End

NO

>> GO TO 3.

REFRIGERATION SYSTEM SYMPTOMS

HA-19

< SYMPTOM DIAGNOSIS >

C

D

E

F

G

H

J

K

L

M

A

B

HA

N

O

P

SYMPTOM DIAGNOSIS

REFRIGERATION SYSTEM SYMPTOMS

WITH COLOR DISPLAY
WITH COLOR DISPLAY : Trouble Diagnoses for Abnormal Pressure

INFOID:0000000009465928

Whenever system

′s high and/or low side pressure is abnormal, diagnose using a manifold gauge. The marker

above the gauge scale in the following tables indicates the standard (usual) pressure range. Since the stan-

dard (usual) pressure, however, differs from vehicle to vehicle, refer to above table (Ambient air temperature-

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 af-
ter water is splashed on con-
denser.

Excessive refrigerant charge in
refrigeration cycle

Reduce refrigerant until speci-
fied pressure is obtained.

Air suction by cooling fan is in-
sufficient.

Insufficient condenser cooling
performance
↓
1.

Condenser fins are
clogged.

2.

Improper fan rotation of
cooling fan

• Clean condenser.
• Check and repair cooling fan

if necessary.

• Low-pressure pipe is not

cold.

• When compressor is

stopped high-pressure val-
ue quickly drops by approx-
imately 196 kPa (2 kg/cm

2

,

28 psi). It then decreases
gradually thereafter.

Poor heat exchange in con-
denser
(After compressor operation
stops, high-pressure decreas-
es too slowly.)
↓
Air in refrigeration cycle

Evacuate and recharge system.

Engine tends to overheat.

Engine cooling systems mal-
function.

Check and repair engine cool-
ing system.

• An area of the low-pressure

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 lit-

tle compared with the speci-
fication.

↓
Improper expansion valve ad-
justment

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 lo-
cated between compressor
and condenser are clogged or
crushed.

• Check and repair or replace

malfunctioning parts.

• Check oil for contamination.

AC360A

HA-20

< SYMPTOM DIAGNOSIS >

REFRIGERATION SYSTEM SYMPTOMS

High-pressure Side is Too Low and Low-pressure Side is Too High

Both High- and Low-pressure Sides are Too Low

Low-pressure Side Sometimes Becomes Negative

Gauge indication

Refrigerant cycle

Probable cause

Corrective action

High-pressure side is too low and
low-pressure side is too high.

High- and low-pressure sides
become equal soon after com-
pressor operation stops.

Compressor pressure opera-
tion is improper.
↓
Damaged inside compressor
packings.

Replace compressor.

No temperature difference be-
tween high- and low-pressure
sides.

Compressor pressure opera-
tion is improper.
↓
Damaged inside compressor
packings.

Replace compressor.

AC356A

Gauge indication

Refrigerant cycle

Probable cause

Corrective action

Both high- and low-pressure sides
are too low.

• There is a big temperature

difference between liquid
tank outlet and inlet. Outlet
temperature is extremely
low.

• Liquid tank inlet and expan-

sion valve are frosted.

Liquid tank inside is slightly
clogged.

• Replace liquid tank.
• Check oil for contamination.

• Temperature of expansion

valve inlet is extremely low
as compared with areas
near liquid tank.

• Expansion valve inlet may

be frosted.

• Temperature difference oc-

curs somewhere in high-
pressure side.

High-pressure pipe located be-
tween liquid tank and expan-
sion valve is clogged.

• Check and repair malfunc-

tioning parts.

• Check oil for contamination.

Expansion valve and liquid
tank are warm or only cool
when touched.

Low refrigerant charge.
↓
Leaking fittings or compo-
nents.

Check refrigerant system for
leaks. Refer to

HA-26, "Leak

Test"

.

There is a big temperature dif-
ference between expansion
valve inlet and outlet while the
valve itself is frosted.

Expansion valve closes a little
compared with the specifica-
tion.
↓
1.

Improper expansion
valve adjustment.

2.

Malfunctioning expansion
valve.

3.

Outlet and inlet may be
clogged.

• Remove foreign particles by

using compressed air.

• Check oil for contamination.

An area of the low-pressure
pipe is colder than areas near
the evaporator outlet.

Low-pressure pipe is clogged
or crushed.

• Check and repair malfunc-

tioning parts.

• Check oil for contamination.

Airflow volume is too low.

Evaporator is frozen.

• Check intake sensor circuit.

Refer to

HAC-38, "Diagnosis

Procedure"

.

• Repair evaporator fins.
• Replace evaporator.
• Refer to

HAC-53,

"Component Function Che
ck"

.

AC353A

REFRIGERATION SYSTEM SYMPTOMS

HA-21

< SYMPTOM DIAGNOSIS >

C

D

E

F

G

H

J

K

L

M

A

B

HA

N

O

P

Low-pressure Side Becomes Negative

WITH COLOR DISPLAY : Symptom Matrix Chart

INFOID:0000000009465929

Gauge indication

Refrigerant cycle

Probable cause

Corrective action

Low-pressure side sometimes be-
comes negative.

• Air conditioning system does

not function and does not cy-
clically cool the compart-
ment air.

• The system constantly func-

tions for a certain period of
time after compressor is
stopped and restarted.

Refrigerant does not discharge
cyclically.
↓
Moisture is frozen at expan-
sion valve outlet and inlet.
↓
Water is mixed with refrigerant.

• Drain water from refrigerant

or replace refrigerant.

• Replace liquid tank.

AC354A

Gauge indication

Refrigerant cycle

Probable cause

Corrective action

Low-pressure side becomes nega-
tive.

Liquid tank or front/rear side of
expansion valve

′s pipe is frost-

ed or dewed.

High-pressure side is closed
and refrigerant does not flow.
↓
Expansion valve or liquid tank
is frosted.

Leave the system at rest until
no frost is present. Start it
again to check whether or not
the malfunction is caused by
water or foreign particles.
• If water is the cause, initially

cooling is okay. Then the wa-
ter freezes causing a block-
age. Drain water from
refrigerant or replace refrig-
erant.

• If due to foreign particles, re-

move expansion valve and
remove the particles with dry
and compressed air (not
shop air).

• If either of the above meth-

ods cannot correct the mal-
function, replace expansion
valve.

• Replace liquid tank.
• Check oil for contamination.

AC362A

Symptom

Reference

A/C system A/C & AV switch is in-
operative.

Go to Trouble Diagnosis Procedure for A/C System.

HAC-62, "A/C AND AV

SWITCH ASSEMBLY : Diagno-

sis Procedure"

A/C system cannot be controlled
from the A/C & AV switch assembly.

Go to Trouble Diagnosis Procedure for A/C and AV switch
assembly System.

HAC-60, "A/C AUTO AMP. : Di-

agnosis Procedure"

Air outlet does not change.

Go to Trouble Diagnosis Procedure for Mode Door Motor.
(LAN)

HAC-49, "Diagnosis Proce-

dure"

Mode door motor does not operate
normally.

Discharge air temperature does not
change.

Go to Trouble Diagnosis Procedure for Air Mix Door Motor.
(LAN)

HAC-45, "Diagnosis Proce-

dure"

(driver side) or

HAC-47,

"Diagnosis Procedure"

(pas-

senger side)

Air mix door motor does not operate
normally.

Intake door does not change.

Go to Trouble Diagnosis Procedure for Intake Door Motor.
(LAN)

HAC-52, "Diagnosis Proce-

dure"

Intake door motor does not operate
normally.

Blower motor operation is malfunc-
tioning.

Go to Trouble Diagnosis Procedure for Blower Motor.

HAC-53, "Diagnosis Proce-

dure"