Infiniti EX35. Manual - part 666

EC-406

< COMPONENT DIAGNOSIS >

[VQ35HR]

P1572 ASCD BRAKE SWITCH

YES

>> INSPECTION END

NO

>> Replace stop lamp switch.

P1572 ICC BRAKE SWITCH

EC-407

< COMPONENT DIAGNOSIS >

[VQ35HR]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

P1572 ICC BRAKE SWITCH

Description

INFOID:0000000003133579

When the brake pedal is depressed, ICC brake switch is turned OFF and stop lamp switch is turned ON. ECM
detects the state of the brake pedal by this input of two kinds (ON/OFF signal).
Refer to 

CCS-17, "System Description"

 for the ICC function.

DTC Logic

INFOID:0000000003133580

DTC DETECTION LOGIC

NOTE:
• If DTC P1572 is displayed with DTC P0605, first perform the trouble diagnosis for DTC P0605. Refer

to 

EC-336, "DTC Logic"

.

• This self-diagnosis has the one trip detection logic. When malfunction A is detected, DTC is not

stored in ECM memory. And in that case, 1st trip DTC and 1st trip freeze frame data are displayed.
1st trip DTC is erased when ignition switch OFF. And even when malfunction A is detected in two
consecutive trips, DTC is not stored in ECM memory.

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
NOTE:
Procedure for malfunction B is not described here. It takes extremely long time to complete procedure for mal-
function B. By performing procedure for malfunction A, the incident that causes malfunction B can be
detected.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

With CONSULT-III

1.

Start engine (VDC switch OFF).

2.

Select “DATA MONITOR” mode with CONSULT-III.

3.

Press MAIN switch and make sure that CRUISE lamp lights up.

4.

Drive the vehicle for at least 5 consecutive seconds under the following conditions.

CAUTION:

Always drive vehicle at a safe speed.
NOTE:
This procedure may be conducted with the drive wheels lifted in the shop or by driving the vehicle.
If a road test is expected to be easier, it is unnecessary to lift the vehicle.

5.

Check 1st trip DTC.

With GST

DTC No.

Trouble diagnosis 

name

DTC detecting condition

Possible cause

P1572

ICC brake switch

A)

ON signals from the stop lamp switch and 
the ICC brake switch are sent to ECM at 
the same time.

• Harness or connectors

(The stop lamp switch circuit is shorted.)

• Harness or connectors

(The ICC brake switch circuit is shorted.)

• Stop  lamp  switch
• ICC brake switch
• ICC brake hold relay
• Incorrect stop lamp switch installation
• Incorrect ICC brake switch installation
• ECM

B)

ICC brake switch signal is not sent to ECM 
for extremely long time while the vehicle is 
driving

VHCL SPEED SE

More than 30 km/h (19 mph)

Selector lever

Suitable position 

EC-408

< COMPONENT DIAGNOSIS >

[VQ35HR]

P1572 ICC BRAKE SWITCH

Follow the procedure “With CONSULT-III” above.

Is 1st trip DTC detected?

YES

>> Go to 

EC-408, "Diagnosis Procedure"

.

NO

>> GO TO 3.

3.

PERFORM DTC CONFIRMATION PROCEDURE

With CONSULT-III

1.

Drive the vehicle for at least 5 consecutive seconds under the following conditions.

CAUTION:

Always drive vehicle at a safe speed.
NOTE:
This procedure may be conducted with the drive wheels lifted in the shop or by driving the vehicle.
If a road test is expected to be easier, it is unnecessary to lift the vehicle.

2.

Check 1st trip DTC.

With GST

Follow the procedure “With CONSULT-III” above.
Is 1st trip DTC detected?

YES

>> Go to 

EC-408, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000003133581

1.

CHECK OVERALL FUNCTION-I

 With CONSULT-III

1.

Turn ignition switch ON.

2.

Select “BRAKE SW1” in “DATA MONITOR” mode with CONSULT-III.

3.

Check “BRAKE SW1” indication under the following conditions.

 Without CONSULT-III

1.

Turn ignition switch ON.

2.

Check the voltage between ECM harness connector terminals under the following conditions.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> GO TO 3.

2.

CHECK OVERALL FUNCTION-II

 With CONSULT-III

Select “BRAKE SW2” and check indication under the following conditions.

VHCL SPEED SE

More than 30 km/h (19 mph)

Selector lever

Suitable position 

Driving location

Depress the brake pedal for more than 
five seconds so as not to come off from 
the above-mentioned vehicle speed.

Monitor item

Condition

Indication

BRAKE SW1

Brake pedal

Slightly depressed

OFF

Fully released

ON

ECM

Condition

Voltage (V)

Connector

+

–

Terminal

Terminal

M107

126

(ICC brake switch signal)

128

Brake pedal

Slightly depressed

Approx. 0

Fully released

Battery voltage

P1572 ICC BRAKE SWITCH

EC-409

< COMPONENT DIAGNOSIS >

[VQ35HR]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

 Without CONSULT-III

Check the voltage between ECM harness connector terminals under the following conditions.

Is the inspection result normal?

YES

>> GO TO 14.

NO

>> GO TO 8.

3.

CHECK ICC BRAKE SWITCH POWER SUPPLY CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect ICC brake switch harness connector.

3.

Turn ignition switch ON.

4.

Check the voltage between ICC brake switch harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> GO TO 4.

4.

DETECT MALFUNCTIONING PART

Check the following.
• Fuse block (J/B) connector E103
• 10A fuse (No. 3)
• Harness for open or short between ICC brake switch and fuse

>> Repair open circuit or short to ground in harness or connectors.

5.

CHECK ICC BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT-II

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Check the continuity between ICC brake switch harness connector and ECM harness connector.

4.

Also check harness for short to ground and short to power.

Is the inspection result normal?

YES

>> GO TO 7.

NO

>> GO TO 6.

6.

DETECT MALFUNCTIONING PART

Check the following.

Monitor item

Condition

Indication

BRAKE SW2

Brake pedal

Slightly depressed

ON

Fully released

OFF

ECM

Condition

Voltage (V)

Connector

+

–

Terminal

Terminal

M107

122

(Stop lamp switch signal)

128

Brake pedal

Slightly depressed

Battery voltage

Fully released

Approx. 0

ICC brake switch

Ground

Voltage

Connector

Terminal

E114

1

Ground

Battery voltage

ICC brake switch

ECM

Continuity

Connector

Terminal

Connector

Terminal

E114

2

M107

126

Existed