Infiniti M45 (Y34). Manual — part 156

TROUBLE DIAGNOSIS

ATC-109

C

D

E

F

G

H

I

K

L

M

A

B

ATC

Intake Sensor Circuit

AJS000CN

COMPONENT DESCRIPTION
Intake Sensor

The intake sensor is located on the heater & cooling unit. It converts
temperature of air after it passes through the evaporator into a resis-
tance value which is then input to the auto amp.

DIAGNOSTIC PROCEDURE FOR INTAKE SENSOR

SYMPTOM: Intake sensor circuit is open or shorted. (24 or

−

24 is

indicated on auto amp. as a result of conducting Self-diagnosis
STEP-2.)

1.

CHECK VOLTAGE BETWEEN INTAKE SENSOR AND GROUND

1.

Disconnect intake sensor connector.

2.

Turn ignition switch ON.

3.

Check voltage between intake sensor harness connector M90
terminal 32 (G/OR) and ground.

OK or NG

OK

>> GO TO 2.

NG

>> GO TO 4.

2.

CHECK CIRCUIT CONTINUITY BETWEEN INTAKE SENSOR AND AUTO AMP.

1.

Turn ignition switch OFF.

2.

Disconnect auto amp. connector.

3.

Check continuity between intake sensor harness connector M90
terminal 36 (R/Y) and auto amp. harness connector M119 termi-
nal 11 (R/Y).

OK or NG

OK

>> GO TO 3.

NG

>> Repair harness or connector.

RJIA0110E

RHA056GA

32 – Ground

: Approx. 5V

RJIA3067E

36 – 11

: Continuity should exist.

RJIA3068E

ATC-110

TROUBLE DIAGNOSIS

3.

CHECK INTAKE SENSOR

Refer to

ATC-110, "Intake Sensor"

.

OK or NG

OK

>> 1. Replace auto amp.

2. Go to self-diagnosis

ATC-50, "FUNCTION CONFIRMATION PROCEDURE"

and perform self-

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

NG

>> 1. Replace intake sensor.

2. Go to self-diagnosis

ATC-50, "FUNCTION CONFIRMATION PROCEDURE"

and perform self-

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

4.

CHECK CIRCUIT CONTINUITY BETWEEN INTAKE SENSOR AND AUTO AMP.

1.

Turn ignition switch OFF.

2.

Disconnect auto amp. connector.

3.

Check continuity between intake sensor harness connector M90
terminal 32 (G/OR) and auto amp. harness connector M119 ter-
minal 1 (G/OR).

4.

Check continuity between auto amp. harness connector M119
terminal 1 (G/OR) and ground.

OK or NG

OK

>> 1. Replace auto amp.

2. Go to self-diagnosis

ATC-50, "FUNCTION CONFIRMATION PROCEDURE"

and perform self-

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

NG

>> Repair harness or connector.

COMPONENT INSPECTION
Intake Sensor

After disconnecting intake sensor harness connector M90, measure
resistance between terminals 32 and 36 at sensor side, using the
table below.

If NG, replace intake sensor.

32 – 1

: Continuity should exist.

1 – Ground

: Continuity should not exist.

RJIA3069E

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

RJIA3070E

TROUBLE DIAGNOSIS

ATC-111

C

D

E

F

G

H

I

K

L

M

A

B

ATC

Multiplex Communication Circuit

AJS000CO

DIAGNOSTIC PROCEDURE FOR MULTIPLEX COMMUNICATION CIRCUIT

SYMPTOM:

●

A/C system does not come on.

●

A/C system cannot be controlled.

1.

CHECK FOR AUTO AMP. OUTPUT

1.

Turn ignition switch ON.

2.

Confirm multiplex communication signal between auto amp. har-
ness connector M119 terminal 9 (W), 20 (B) and ground using
an oscilloscope.

OK or NG

OK

>> GO TO 2.

NG

>> Replace auto amp.

RJIA1311E

Terminals

Voltage

(+)

(-)

Auto amp.

connector

Terminal No.

(Wire color)

M119

9 (L/W)

Ground

M119

20 (L/R)

RJIA3071E

RJIA0212E

HAK0363D

ATC-112

TROUBLE DIAGNOSIS

2.

CHECK CIRCUIT CONTINUITY BETWEEN AV C/U (AV AND NAVI C/U) AND AUTO AMP.

1.

Turn ignition switch OFF.

2.

Disconnect AV C/U (AV and NAVI C/U) and auto amp. connector.

3.

Check continuity between AV and NAVI C/U harness connector B29 terminals 37 (L/W), 39 (L/R) or AV C/
U harness connector M77 terminals 44 (L/W), 45 (L/R) and auto amp. harness connector M119 terminals
9 (L/W), 20 (L/R).

OK or NG

OK

>> GO TO 3.

NG

>> Repair harness or connector.

3.

CHECK FOR AUTO AMP. INPUT

1.

Reconnect AV C/U (AV and NAVI C/U) and auto amp. connector.

2.

Turn ignition switch ON.

3.

Confirm multiplex communication signal between auto amp. har-
ness connector M119 terminal 10 (R) and ground using an oscil-
loscope.

OK or NG

OK

>> INSPECTION END

NG

>> GO TO 4.

RJIA1312E

Terminals

Continuity

AV C/U or AV and

NAVI C/U connector

Terminal No.

(Wire color)

Auto amp.

connector

Terminal No.

(Wire color)

AV C/U

M77

44 (L/W)

M119

9 (L/W)

Yes

M77

45 (L/R)

M119

20 (L/R)

AV and NAVI C/U

B29

37 (L/W)

M119

9 (L/W)

B29

39 (L/R)

M119

20 (L/R)

Terminals

Voltage

(+)

(-)

Auto amp.

connector

Terminal No.

(Wire color)

M119

10 (L)

Ground

RJIA3073E

RJIA0213E