Infiniti QX56 (JA60). Manual - part 438

EC-404

< COMPONENT DIAGNOSIS >

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ICC BRAKE SWITCH

4. Check voltage between ICC brake switch terminal 1 and ground

with CONSULT-III or tester.

OK or NG

OK

>> GO TO 6.

NG

>> GO TO 3.

3.

CHECK ICC BRAKE SWITCH POWER SUPPLY CIRCUIT-II

1. Turn ignition switch OFF.

2. Disconnect ICC brake hold relay.

3. Check harness continuity between ICC brake switch terminal 1 and ICC brake hold relay terminal 3.

Refer to Wiring Diagram

OK or NG

OK

>> GO TO 4.

NG

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

4.

CHECK ICC BRAKE HOLD RELAY POWER SUPPLY CIRCUIT

1. Turn ignition switch ON.

2. Check the voltage between ICC brake hold relay terminal 4 and

ground with CONSULT-III or tester.

OK or NG

OK

>> GO TO 8.

NG

>> GO TO 5.

5.

DETECT MALFUNCTIONING PART

Check the following.

• Harness connectors M31, E152

• Fuse block (J/B) connector M4

• 10 A fuse (No.15)

• Harness for open or short between ICC brake hold relay and fuse

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

6.

CHECK ICC BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

Voltage: Battery voltage

PBIB0857E

BBIA0471E

Continuity should exist.

Voltage: Battery voltage

MBIB0059E

ICC BRAKE SWITCH

EC-405

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1. Turn ignition switch OFF.

2. Disconnect ECM harness connector.

3. Check harness continuity between ICC brake switch terminal 2 and ECM terminal 108, ICC brake switch

terminal 2 and ICC unit terminal 29.

Refer Wiring Diagram.

4. Also check harness for short to ground and short to power.
OK or NG

OK

>> GO TO 7.

NG

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

7.

CHECK ICC BRAKE SWITCH

Refer to 

EC-343, "Component Inspection"

.

OK or NG

OK

>> GO TO 10.

NG

>> Replace ICC brake switch.

8.

CHECK ICC BRAKE HOLD RELAY POWER SUPPLY AND GROUND CIRCUIT FOR OPEN AND SHORT

1. Check harness continuity between ICC brake hold relay terminal 1 and ICC unit terminal 47, ICC brake

hold relay terminal 2 and ground.

Refer to Wiring Diagram

2. Also check harness for short to ground or short to power in harness or connectors.
OK or NG

OK

>> GO TO 9.

NG

>> Repair or replace.

9.

CHECK ICC BRAKE HOLD RELAY

Refer to 

EC-343, "Component Inspection"

.

OK

>> GO TO 10.

NG

>> Replace ICC brake hold relay.

10.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-35, "How to Check Terminal"

 and 

GI-38, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000005149481

ICC BRAKE SWITCH

1. Turn ignition switch OFF.
2. Disconnect ICC brake switch harness connector.
3. Check continuity between ICC brake switch terminals 1 and 2

under the following conditions.

If NG, adjust ICC brake switch installation, refer to 

BR-15,

"Inspection and Adjustment"

, and perform step 3 again.

Continuity should exist.

Continuity should exist

Condition

Continuity

Brake pedal: Fully released.

Should exist.

Brake pedal: Slightly depressed.

Should not exist.

PBIB1536E

EC-406

< COMPONENT DIAGNOSIS >

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ICC BRAKE SWITCH

ICC BRAKE HOLD RELAY

1. Apply 12V direct current between ICC brake hold relay terminals 1 and 2.
2. Check continuity between relay terminals 3 and 4, 6 and 7 under

the following conditions.

3. If NG, replace ICC brake hold relay.

Condition

Between terminals

Continuity

12 V direct current supply 
between terminals 1 and 2

3 and 4

Should not exist

6 and 7

Should exist

No current supply

3 and 4

Should exist

6 and 7

Should not exist

MBIB0063E

IGNITION SIGNAL

EC-407

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IGNITION SIGNAL

Component Description

INFOID:0000000005149482

IGNITION COIL & POWER TRANSISTOR

The ignition signal from the ECM is sent to and amplified by the power transistor. The power transistor turns

ON and OFF the ignition coil primary circuit. This ON/OFF operation induces the proper high voltage in the coil

secondary circuit.

Diagnosis Procedure

INFOID:0000000005149483

1.

CHECK ENGINE START

Turn ignition switch OFF, and restart engine.

Is engine running?
Yes or No

Yes (With CONSULT-III)>>GO TO 2.

Yes (Without CONSULT-III)>>GO TO 3.

No

>> GO TO 4.

2.

CHECK OVERALL FUNCTION

 With CONSULT-III

1. Perform “POWER BALANCE” in “ACTIVE TEST” mode with CONSULT-III.

2. Make sure that each circuit produces a momentary engine speed drop.
OK or NG

OK

>> INSPECTION END

NG

>> GO TO 10.

3.

CHECK OVERALL FUNCTION

 Without CONSULT-III

1. Let engine idle.

2. Read the voltage signal between ECM terminals 46, 60, 61, 62,

65, 79, 80, 81 and ground with an oscilloscope.

3. Verify that the oscilloscope screen shows the signal wave as

shown below.

NOTE:

The pulse cycle changes depending on rpm at idle.

OK or NG

1.

Ignition coils (with power transistor) 
(bank 2)

2.

Ignition coils (with power transistor) 
(bank 1)

BBIA0777E

PBIB2094E

PBIB0044E