Nissan Tiida C11. Manual - part 842

HAC-32

< COMPONENT DIAGNOSIS >

[MANUAL AIR CONDITIONER]

INTAKE SENSOR

After disconnecting intake sensor connector M42, measure resis-
tance between terminals 1 and 2 at sensor side, using the table
below.

If NG, replace intake sensor. Refer to XXXX.

Temperature 

°

C (

°

F)

Resistance k

Ω

 

−

15 (5)

12.34

 

−

10 (14)

9.62

 

−

5 (23)

7.56

0 (32)

6.00

5 (41)

4.80

10 (50)

3.87

15 (59)

3.15

20 (68)

2.57

25 (77)

2.12

30 (86)

1.76

35 (95)

1.47

40 (104)

1.23

45 (113)

1.04

SJIA0828E

PTC HEATER CONTROL SYSTEM

HAC-33

< COMPONENT DIAGNOSIS >

[MANUAL AIR CONDITIONER]

C

D

E

F

G

H

J

K

L

M

A

B

HAC

N

O

P

PTC HEATER CONTROL SYSTEM

PTC HEATER (300 WATT)

PTC HEATER (300 WATT) : PTC Heater System Description

INFOID:0000000001674171

SYSTEM DESCRIPTION

The PTC heater system is controlled by ambient temperature, water temperature, FAN ON signal and temper-
ature control dial. Hot air is supplied to a discharge air outlet by PTC heater that generates heat electrically
even when engine coolant temperature is low.

Component Parts

PTC heater system components are:

• PTC control unit
• PTC heater
• PTC  relay-1
• Water temperature sensor
• Full hot switch
• Ambient sensor

System Operation

PTC heater system starts when all the following conditions are met:
• Less than 35 minutes after ignition switch ON.
• Blower control dial ON (Blower motor operates.) and temperature control dial full hot position (Full hot switch

ON).

• Ambient temperature is lower than 0

°

C (32

°

F).

• Engine coolant temperature is lower than 65

°

C (149

°

F) (condition

1), or when it becomes lower than 60

°

C (140

°

F) again (condition 2)

on startup.

• Engine speed is more than 1100 rpm and after a lapse of more

than 10 seconds.

PTC heater system stops when any of the following conditions is
met:
• More than 35 minutes later after ignition switch ON.
• Blower control dial OFF (Blower motor OFF) and/or temperature

control dial except full hot position (Full hot switch OFF).

• Ambient temperature is higher than 0

°

C (32

°

F).

• Engine coolant temperature is higher than 65

°

C (149

°

F).

• When engine speed becomes less than 800 rpm.

SJIA0968E

AWIIA0354GB

HAC-34

< COMPONENT DIAGNOSIS >

[MANUAL AIR CONDITIONER]

PTC HEATER CONTROL SYSTEM

PTC HEATER (300 WATT) : PTC Heater Component Description

INFOID:0000000001674172

COMPONENT DESCRIPTION

PTC Control Unit

The PTC control unit is attached on the A/C unit assembly. It controls
PTC heater by ambient temperature, water temperature, FAN ON
signal and temperature control dial.

PTC Heater

The PTC heater is attached on the A/C unit assembly. It generates
heat electrically.

Ambient Sensor

The ambient sensor is attached on the radiator core support upper. It
detects ambient temperature and converts it into a resistance value
which is then input into the PTC control unit.

Water Temperature Sensor

The water temperature sensor is attached on heater pipe. It detects
water temperature and converts it into a resistance value which is
then input in to PTC control unit.

Full Hot Switch

SJIA0906E

SJIA0907E

AWIIA0600ZZ

SJIA0908E

PTC HEATER CONTROL SYSTEM

HAC-35

< COMPONENT DIAGNOSIS >

[MANUAL AIR CONDITIONER]

C

D

E

F

G

H

J

K

L

M

A

B

HAC

N

O

P

The full hot switch is attached on the A/C unit assembly. When the
temperature control dial at full hot position, and then full hot switch
turned ON.

PTC HEATER (300 WATT) : PTC Heater (300 Watt) Diagnosis Procedure

INFOID:0000000001674173

DIAGNOSTIC PROCEDURE FOR PTC SYSTEM

SYMPTOM: PTC heater system operation is malfunction.

1.

CHECK POWER SUPPLY FOR PTC RELAY-1

1.

Turn ignition switch ON.

2.

Check voltage between PTC relay-1 harness connector E61 ter-
minals 2, 3, and ground.

Is the inspection result normal

YES

>> GO TO 2.

NO

>>

Check power supply circuit and 10A fuse and 40A fusible link (No. 2 and I, located in the fuse
block). Refer to XX.

• If fuses are OK, check harness for open circuit. Repair or replace if necessary.
• If fuses are NG, replace fuse and check harness for short circuit. Repair or replace if necessary.

2.

CHECK PTC RELAY-1

1.

Turn ignition switch OFF.

2.

Check PTC relay-1. Refer to 

HAC-41, "PTC HEATER (300 WATT) : PTC Heater (300 Watt) Component

Inspection"

.

Is the inspection result normal

YES

>> GO TO 3.

NO

>> Replace PTC relay-1. Refer to XX.

3.

CHECK PTC RELAY-1 OUTPUT CIRCUIT

1.

Disconnect ambient sensor, PTC heater and water temperature
sensor connectors.

2.

Turn temperature control dial clockwise until full hot position.

3.

Turn mode control dial to foot position.

4.

Start the engine.

5.

Turn blower control dial to maximum speed.

6.

Check resistance between PTC relay-1 harness connector E61
terminal 1 and ground.

Is the inspection result normal

YES

>> GO TO 5.

SJIA0909E

Terminals

Voltage

(Approx.)

(+)

(

−

)

Connector

Terminal

Ground

Battery voltage

PTC relay-1: E61

2

3

SJIA0913E

Connector

Terminal

Ground

Continuity

PTC relay-1: E61

1

Yes

AWIIA0455ZZ