Nissan Murano Z50 (2005 year). Manual — part 8

TROUBLE DIAGNOSIS

ATC-89

C

D

E

F

G

H

I

K

L

M

A

B

ATC

Revision: 2005 August

2005 Murano

PERFORMANCE CHART
Test Condition

Testing must be performed as follows:

Test Reading

Recirculating-to-discharge Air Temperature Table

Ambient Air Temperature-to-operating Pressure Table

Vehicle condition

Indoors or in the shade (in a well-ventilated place)

Doors

Closed

Door windows

Open

Hood

Open

TEMP.

Max. COLD

Mode switch

(Ventilation) set

Recirculation (REC) switch

(Recirculation) set

Fan (blower) speed

Max. speed set

Engine speed

Idle speed

Operate the air conditioning system for 10 minutes before taking measurements.

Inside air (Recirculating air) at blower assembly inlet

Discharge air temperature at center ventilator

°

C (

°

F)

Relative humidity

%

Air temperature

°

C (

°

F)

50 - 60

20 (68)

5.3 - 6.5 (42 - 44)

25 (77)

9.7 - 11.5 (49 - 53)

30 (86)

13.8 - 16.3 (57 - 61)

35 (95)

18.0 - 21.2 (64 - 70)

40 (104)

22.2 - 25.7 (72 - 78)

60 - 70

20 (68)

6.5 - 7.7 (44 - 46)

25 (77)

11.5 - 13.3 (53 - 56)

30 (86)

16.3 - 18.8 (61 - 66)

35 (95)

21.2 - 24.0 (70 - 75)

40 (104)

25.7 - 29.2 (78 - 85)

Ambient air

High-pressure (Discharge side)

kPa (kg/cm

2

, psi)

Low-pressure (Suction side)

kPa (kg/cm

2

, psi)

Relative humidity

%

Air temperature

°

C (

°

F)

50 - 70

20 (68)

680 - 840

(6.94 - 8.57, 98.6 - 121.8)

160 - 198

(1.63 - 2.02, 23.2 - 28.7)

25 (77)

800 - 985

(8.16 - 10.05, 116.0 - 142.8)

198 - 245

(2.02 - 2.50, 28.7 - 35.5)

30 (86)

940 - 1,150

(9.59 - 11.73, 136.3 - 166.8)

225 - 278

(2.30 - 2.84, 32.6 - 40.3)

35 (95)

1,160 - 1,410

(11.83 - 14.38, 168.2 - 204.5)

273 - 335

(2.78 - 3.42, 39.6 - 48.6)

40 (104)

1,325 - 1,620

(13.52 - 16.20, 192.1 - 234.9)

325 - 398

(3.32 - 4.06, 47.1 - 57.7)

ATC-90

TROUBLE DIAGNOSIS

Revision: 2005 August

2005 Murano

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

TROUBLE DIAGNOSIS

ATC-91

C

D

E

F

G

H

I

K

L

M

A

B

ATC

Revision: 2005 August

2005 Murano

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

Both High- and Low-pressure Sides are Too Low

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
between high- and low-pres-
sure 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 lubricant for contami-
nation.

●

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

●

Expansion valve inlet may
be frosted.

●

Temperature difference
occurs somewhere in high-
pressure side.

High-pressure pipe located
between liquid tank and
expansion valve is clogged.

●

Check and repair malfunc-
tioning parts.

●

Check lubricant for contami-
nation.

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

Low refrigerant charge.

↓

Leaking fittings or compo-
nents.

Check refrigerant for leaks.
Refer to

ATC-149, "Checking

for Refrigerant Leaks"

.

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.

●

Replace expansion valve.

●

Check lubricant for contami-
nation.

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 lubricant for contami-
nation.

Air flow volume is not enough
or is too low.

Evaporator is frozen.

●

Check intake sensor circuit.
Refer to

ATC-106, "Intake

Sensor Circuit"

.

●

Replace compressor.

●

Repair evaporator fins.

●

Replace evaporator.

●

Refer to

ATC-74, "Blower

Motor Circuit"

.

AC353A

ATC-92

TROUBLE DIAGNOSIS

Revision: 2005 August

2005 Murano

Low-pressure Side Sometimes Becomes Negative

Low-pressure Side Becomes Negative

Gauge indication

Refrigerant cycle

Probable cause

Corrective action

Low-pressure side sometimes
becomes negative.

●

Air conditioning system
does not function and does
not cyclically cool the com-
partment air.

●

The system constantly func-
tions for a certain period of
time after compressor is
stopped and restarted.

Refrigerant does not dis-
charge cyclically.

↓

Moisture is frozen at expan-
sion valve outlet and inlet.

↓

Water is mixed with refriger-
ant.

●

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
frosted 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
water freezes causing a
blockage. Drain water from
refrigerant or replace refrig-
erant.

●

If due to foreign particles,
remove 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 lubricant for contami-
nation.

AC362A

TROUBLE DIAGNOSIS

ATC-93

C

D

E

F

G

H

I

K

L

M

A

B

ATC

Revision: 2005 August

2005 Murano

Insufficient Heating

AJS00110

SYMPTOM: Insufficient heating

INSPECTION FLOW

*1

ATC-56, "Operational Check"

*2

ATC-68, "Air Mix Door Motor Circuit"

*3

ATC-49, "FUNCTION CONFIRMA-
TION PROCEDURE"

, see No. 4 to 6.

*4

ATC-49, "FUNCTION CONFIRMA-
TION PROCEDURE"

, see No. 13.

*5

ATC-61, "LAN System Circuit"

*6

ATC-74, "Blower Motor Circuit"

*7

EC-205, "DTC P0117, P0118 ECT
SENSOR"

*8

CO-9, "Changing Engine Coolant"

*9

CO-15, "Checking Radiator Cap"

SJIA0528E

ATC-94

TROUBLE DIAGNOSIS

Revision: 2005 August

2005 Murano

Noise

AJS000ZF

SYMPTOM: Noise

INSPECTION FLOW

*1

Compressor Clutch,

ATC-136,

"REMOVAL"

*2

Compressor Clutch,

ATC-137,

"INSTALLATION"

*3

ATC-22, "Maintenance of Lubricant
Quantity in Compressor"

*4

ATC-56, "Operational Check"

*5

EM-13, "Checking Drive Belts"

RJIA3108E

TROUBLE DIAGNOSIS

ATC-95

C

D

E

F

G

H

I

K

L

M

A

B

ATC

Revision: 2005 August

2005 Murano

Self-diagnosis

AJS000ZG

SYMPTOM: Self-diagnosis cannot be performed.

INSPECTION FLOW

*1

ATC-58, "Power Supply and Ground
Circuit for Auto Amp."

*2

ATC-97, "Ambient Sensor Circuit"

*3

ATC-100, "In-vehicle Sensor Circuit"

*4

ATC-103, "Sunload Sensor Circuit"

*5

ATC-106, "Intake Sensor Circuit"

*6

ATC-70, "Air Mix Door Motor PBR
Circuit"

*7

ATC-56, "Operational Check"

*8

ATC-37, "SYMPTOM TABLE"

RJIA1798E

ATC-96

TROUBLE DIAGNOSIS

Revision: 2005 August

2005 Murano

Memory Function

AJS000ZH

SYMPTOM: Memory function does not operate.

INSPECTION FLOW

*1

ATC-58, "Power Supply and Ground
Circuit for Auto Amp."

*2

ATC-56, "Operational Check"

*3

ATC-49, "FUNCTION CONFIRMA-
TION PROCEDURE"

RJIA1799E

TROUBLE DIAGNOSIS

ATC-97

C

D

E

F

G

H

I

K

L

M

A

B

ATC

Revision: 2005 August

2005 Murano

Ambient Sensor Circuit

AJS00111

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 (0.6

°

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 E15
terminal 1 (B/R) and ground.

OK or NG

OK

>> GO TO 2.

NG

>> GO TO 4.

RJIA3971E

RJIA1461E

1 – Ground

: Approx. 5 V

RJIA2017E

ATC-98

TROUBLE DIAGNOSIS

Revision: 2005 August

2005 Murano

2.

CHECK CIRCUIT CONTINUITY BETWEEN AMBIENT SENSOR AND UNIFIED METER AND A/C AMP.

1.

Turn ignition switch OFF.

2.

Disconnect unified meter and A/C amp. connector.

3.

Check continuity between ambient sensor harness connector
E15 terminal 2 (B/Y) and unified meter and A/C amp. harness
connector M51 terminal 49 (B/Y).

OK or NG

OK

>> GO TO 3.

NG

>> Repair harness or connector.

3.

CHECK AMBIENT SENSOR

Refer to

ATC-99, "Ambient Sensor"

.

OK or NG

OK

>> 1. Replace unified meter and A/C amp.

2. Go to self-diagnosis

ATC-49, "FUNCTION CONFIRMATION PROCEDURE"

and perform self-

diagnosis STEP-2. Confirm that code No. 20 is displayed.

NG

>> 1. Replace ambient sensor.

2. Go to self-diagnosis

ATC-49, "FUNCTION CONFIRMATION PROCEDURE"

and perform self-

diagnosis STEP-2. Confirm that code No. 20 is displayed.

4.

CHECK CIRCUIT CONTINUITY BETWEEN AMBIENT SENSOR AND UNIFIED METER AND A/C AMP.

1.

Turn ignition switch OFF.

2.

Disconnect unified meter and A/C amp. connector.

3.

Check continuity between ambient sensor harness connector
E15 terminal 1 (B/R) and unified meter and A/C amp. harness
connector M51 terminal 39 (B/R).

4.

Check continuity between ambient sensor harness connector
E15 terminal 1 (B/R) and ground.

OK or NG

OK

>> 1. Replace unified meter and A/C amp.

2. Go to self-diagnosis

ATC-49, "FUNCTION CONFIRMATION PROCEDURE"

and perform self-

diagnosis STEP-2. Confirm that code No. 20 is displayed.

NG

>> Repair harness or connector.

2 – 49

: Continuity should exist.

RJIA2018E

1 – 39

: Continuity should exist.

1 – Ground

: Continuity should not exist.

RJIA2019E

TROUBLE DIAGNOSIS

ATC-99

C

D

E

F

G

H

I

K

L

M

A

B

ATC

Revision: 2005 August

2005 Murano

COMPONENT INSPECTION
Ambient Sensor

After disconnecting ambient sensor connector E15, measure resis-
tance between terminals 1 (B/R) and 2 (B/Y) at sensor side, using
the table below.

If NG, replace ambient sensor.

Temperature

°

C (

°

F)

Resistance k

Ω

−

15 (5)

12.73

−

10 (14)

9.92

−

5 (23)

7.80

0 (32)

6.19

5 (41)

4.95

10 (50)

3.99

15 (59)

3.24

20 (68)

2.65

25 (77)

2.19

30 (86)

1.81

35 (95)

1.51

40 (104)

1.27

45 (113)

1.07

RJIA3972E

ATC-100

TROUBLE DIAGNOSIS

Revision: 2005 August

2005 Murano

In-vehicle Sensor Circuit

AJS00112

COMPONENT DESCRIPTION
In-vehicle Sensor

The in-vehicle sensor is located on instrument driver lower panel. It
converts variations in temperature of compartment air drawn from
the aspirator into a resistance value. It is then input into the unified
meter and A/C amp.

Aspirator

The aspirator is located on driver’s side of heater & cooling unit
assembly. It produces vacuum pressure due to air discharged from
the heater & cooling unit assembly, continuously taking compartment
air in the aspirator.

RJIA1802E

RJIA1803E

RJIA1804E

TROUBLE DIAGNOSIS

ATC-101

C

D

E

F

G

H

I

K

L

M

A

B

ATC

Revision: 2005 August

2005 Murano

DIAGNOSIS PROCEDURE FOR IN-VEHICLE SENSOR

SYMPTOM: In-vehicle sensor circuit is open or shorted. (22 or

−

22 is

indicated on unified meter and A/C amp. as a result of performing
self-diagnosis STEP-2.)

1.

CHECK VOLTAGE BETWEEN IN-VEHICLE SENSOR AND GROUND

1.

Disconnect in-vehicle sensor connector.

2.

Turn ignition switch ON.

3.

Check voltage between in-vehicle sensor harness connector
M52 terminal 1 (LG) and ground.

OK or NG

OK

>> GO TO 2.

NG

>> GO TO 4.

2.

CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE SENSOR AND UNIFIED METER AND A/C

AMP.

1.

Turn ignition switch OFF.

2.

Disconnect unified meter and A/C amp. connector.

3.

Check continuity between in-vehicle sensor harness connector
M52 terminal 2 (B/Y) and unified meter and A/C amp. harness
connector M51 terminal 49 (B/Y).

OK or NG

OK

>> GO TO 3.

NG

>> Repair harness or connector.

3.

CHECK IN-VEHICLE SENSOR

Refer to

ATC-102, "In-vehicle Sensor"

.

OK or NG

OK

>> 1. Replace unified meter and A/C amp.

2. Go to self-diagnosis

ATC-49, "FUNCTION CONFIRMATION PROCEDURE"

and perform self-

diagnosis STEP-2. Confirm that code No. 20 is displayed.

NG

>> 1. Replace in-vehicle sensor.

2. Go to self-diagnosis

ATC-49, "FUNCTION CONFIRMATION PROCEDURE"

and perform self-

diagnosis STEP-2. Confirm that code No. 20 is displayed.

RJIA1452E

1 – Ground

: Approx. 5 V

RJIA2022E

2 – 49

: Continuity should exist.

RJIA2023E

ATC-102

TROUBLE DIAGNOSIS

Revision: 2005 August

2005 Murano

4.

CHECK CIRCUIT CONTINUITY BETWEEN IN-VEHICLE SENSOR AND UNIFIED METER AND A/C

AMP.

1.

Turn ignition switch OFF.

2.

Disconnect unified meter and A/C amp. connector.

3.

Check continuity between in-vehicle sensor harness connector
M52 terminal 1 (LG) and unified meter and A/C amp. harness
connector M51 terminal 40 (LG).

4.

Check continuity between in-vehicle sensor harness connector
M52 terminal 1 (LG) and ground.

OK or NG

OK

>> 1. Replace unified meter and A/C amp.

2. Go to self-diagnosis

ATC-49, "FUNCTION CONFIRMATION PROCEDURE"

and perform self-

diagnosis STEP-2. Confirm that code No. 20 is displayed.

NG

>> Repair harness or connector.

COMPONENT INSPECTION
In-vehicle Sensor

After disconnecting in-vehicle sensor connector M52, measure resis-
tance between terminals 1 (LG) and 2 (B/Y) at sensor side, using the
table below.

If NG, replace in-vehicle sensor.

1 – 40

: Continuity should exist.

1 – Ground

: Continuity should not exist.

RJIA2024E

Temperature

°

C (

°

F)

Resistance k

Ω

−

15 (5)

12.73

−

10 (14)

9.92

−

5 (23)

7.80

0 (32)

6.19

5 (41)

4.95

10 (50)

3.99

15 (59)

3.24

20 (68)

2.65

25 (77)

2.19

30 (86)

1.81

35 (95)

1.51

40 (104)

1.27

45 (113)

1.07

RJIA1805E

TROUBLE DIAGNOSIS

ATC-103

C

D

E

F

G

H

I

K

L

M

A

B

ATC

Revision: 2005 August

2005 Murano

Sunload Sensor Circuit

AJS00113

COMPONENT DESCRIPTION
Sunload Sensor

The sunload sensor is located on the passenger side instrument
mask. It detects sunload entering through windshield by means of a
photo diode. The sensor converts the sunload into a current value
which is then input into the unified meter and A/C amp.

SUNLOAD INPUT PROCESS

The unified meter and A/C amp. also includes a processing circuit which averages the variations in detected
sunload over a period of time. This prevents drastic swings in the ATC system operation due to small or quick
variations in detected sunload.
For example, consider driving along a road bordered by an occasional group of large trees. The sunload
detected by the sunload sensor will vary whenever the trees obstruct the sunlight. The processing circuit aver-
ages the detected sunload over a period of time, so that the (insignificant) effect of the trees momentarily
obstructing the sunlight does not cause any change in the ATC system operation. On the other hand, shortly
after entering a long tunnel, the system will recognize the change in sunload, and the system will react accord-
ingly.

DIAGNOSIS PROCEDURE FOR SUNLOAD SENSOR

SYMPTOM: Sunload sensor circuit is open or shorted. (25 or

−

25 is

indicated on unified meter and A/C amp. as a result of performing
self-diagnosis STEP-2.)

1.

CHECK VOLTAGE BETWEEN SUNLOAD SENSOR AND GROUND

1.

Disconnect sunload sensor connector.

2.

Turn ignition switch ON.

3.

Check voltage between sunload sensor harness connector M79
terminal 1 (O) and ground.

OK or NG

OK

>> GO TO 2.

NG

>> GO TO 4.

RJIA1806E

RJIA1455E

1 – Ground

: Approx. 5 V

RJIA2027E

ATC-104

TROUBLE DIAGNOSIS

Revision: 2005 August

2005 Murano

2.

CHECK CIRCUIT CONTINUITY BETWEEN SUNLOAD SENSOR AND UNIFIED METER AND A/C AMP.

1.

Turn ignition switch OFF.

2.

Disconnect unified meter and A/C amp. connector.

3.

Check continuity between sunload sensor harness connector
M79 terminal 2 (B/Y) and unified meter and A/C amp. harness
connector M51 terminal 49 (B/Y).

OK or NG

OK

>> GO TO 3.

NG

>> Repair harness or connector.

3.

CHECK SUNLOAD SENSOR

1.

Reconnect sunload sensor connector and unified meter and A/C amp. connector.

2.

Refer to

ATC-105, "Sunload Sensor"

.

OK or NG

OK

>> 1. Replace unified meter and A/C amp.

2. Go to self-diagnosis

ATC-49, "FUNCTION CONFIRMATION PROCEDURE"

and perform self-

diagnosis STEP-2. Confirm that code No. 20 is displayed.

NG

>> 1. Replace sunload sensor.

2. Go to self-diagnosis

ATC-49, "FUNCTION CONFIRMATION PROCEDURE"

and perform self-

diagnosis STEP-2. Confirm that code No. 20 is displayed.

4.

CHECK CIRCUIT CONTINUITY BETWEEN SUNLOAD SENSOR AND UNIFIED METER AND A/C AMP.

1.

Turn ignition switch OFF.

2.

Disconnect unified meter and A/C amp. connector.

3.

Check continuity between sunload sensor harness connector
M79 terminal 1 (O) and unified meter and A/C amp. harness
connector M51 terminal 50 (O).

4.

Check continuity between sunload sensor harness connector
M79 terminal 1 (O) and ground.

OK or NG

OK

>> 1. Replace unified meter and A/C amp.

2. Go to self-diagnosis

ATC-49, "FUNCTION CONFIRMATION PROCEDURE"

and perform self-

diagnosis STEP-2. Confirm that code No. 20 is displayed.

NG

>> Repair harness or connector.

2 – 49

: Continuity should exist.

RJIA2028E

1 – 50

: Continuity should exist.

1 – Ground

: Continuity should not exist.

RJIA2029E