Infiniti Q45. Manual - part 462

DTC P0603 ECM POWER SUPPLY

EC-487

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Specification data are reference values and are measured between each terminal and ground.

CAUTION:

Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.

Diagnostic Procedure

NBS001ZB

1. 

CHECK ECM POWER SUPPLY

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Check voltage between ECM terminal 121 and ground with
CONSULT-II or tester.

OK or NG

OK

>> GO TO 3.

NG

>> GO TO 2.

2. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors M135, F105

●

10A fuse

●

Fuse block (J/B) No. 2 harness connector M145

●

Harness for open or short between ECM and battery

>> Repair or replace harness or connectors.

3. 

CHECK INTERMITTENT INCIDENT

Refer to 

EC-145, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

OK or NG

OK

>> GO TO 4.

NG

>> Repair or replace harness or connectors.

TER-

MINAL 

NO.

WIRE 

COLOR

ITEM

CONDITION

DATA (DC Voltage)

121

W

Power supply for ECM 
(Back-up)

[Ignition switch: OFF]

BATTERY VOLTAGE
(11 - 14V)

Voltage: Battery voltage

MBIB0026E

EC-488

DTC P0603 ECM POWER SUPPLY

4. 

PERFORM DTC CONFIRMATION PROCEDURE

 With CONSULT-II

1.

Turn ignition switch ON.

2.

Select “SELF DIAG RESULTS” mode with CONSULT-II.

3.

Touch “ERASE”.

4.

Perform DTC Confirmation Procedure.
See 

EC-485, "DTC Confirmation Procedure"

 .

5.

Is the 1st trip DTC P0603 displayed again?

 With GST

1.

Turn ignition switch ON.

2.

Select “Service $04” with GST.

3.

Perform DTC Confirmation Procedure.
See 

EC-485, "DTC Confirmation Procedure"

 .

4.

Is the 1st trip DTC P0603 displayed again?

Yes or No

Yes

>> GO TO 5.

No

>> INSPECTION END

5. 

REPLACE ECM

1.

Replace ECM.

2.

Perform initialization of IVIS (NATS) system and registration of all IVIS (NATS) ignition key IDs. Refer to

BL-202, "ECM Re-Communicating Function"

 .

3.

Perform 

EC-77, "VIN Registration"

 .

4.

Perform 

EC-77, "Accelerator Pedal Released Position Learning"

 .

5.

Perform 

EC-78, "Throttle Valve Closed Position Learning"

 .

6.

Perform 

EC-78, "Idle Air Volume Learning"

 .

>> INSPECTION END

DTC P0605 ECM

EC-489

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DTC P0605 ECM

PFP:23710

Component Description

NBS001Z3

The ECM consists of a microcomputer and connectors for signal
input and output and for power supply. The ECM controls the engine.

On Board Diagnosis Logic

NBS001Z4

This self-diagnosis has one or two trip detection logic.

FAIL-SAFE MODE

ECM enters fail-safe mode when the malfunction A is detected.

DTC Confirmation Procedure

NBS001Z5

Perform PROCEDURE FOR MALFUNCTION A first. If the 1st trip DTC cannot be confirmed, perform
PROCEDURE FOR MALFUNCTION B. If there is no malfunction on PROCEDURE FOR MALFUNCTION
B, perform PROCEDURE FOR MALFUNCTION C.

NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.

PROCEDURE FOR MALFUNCTION A

 With CONSULT-II

1.

Turn ignition switch ON.

2.

Select “DATA MONITOR” mode with CONSULT-II.

3.

If 1st trip DTC is detected, go to 

EC-490, "Diagnostic Procedure"

.

 With GST

Follow the procedure “With CONSULT-II” above.

PBIB1164E

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0605
0605

Engine control module

A)

ECM calculation function is malfunctioning.

●

ECM

B)

ECM EEP-ROM system is malfunctioning.

C)

ECM self shut-off function is malfunctioning.

Detected items

Engine operation condition in fail-safe mode

Malfunction A

●

ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 
degrees) by the return spring.

●

ECM deactivates ASCD operation.

SEF058Y

EC-490

DTC P0605 ECM

PROCEDURE FOR MALFUNCTION B

 With CONSULT-II

1.

Turn ignition switch ON and wait at least 1 second.

2.

Select “DATA MONITOR” mode with CONSULT-II.

3.

Turn ignition switch OFF, wait at least 10 seconds, and then turn
ON.

4.

If 1st trip DTC is detected, go to 

EC-490, "Diagnostic Procedure"

.

 With GST

Follow the procedure “With CONSULT-II” above.

PROCEDURE FOR MALFUNCTION C

 With CONSULT-II

1.

Turn ignition switch ON and wait at least 1 second.

2.

Select “DATA MONITOR” mode with CONSULT-II.

3.

Turn ignition switch OFF, wait at least 10 seconds, and then turn
ON.

4.

Repeat step 3 for 32 times.

5.

If 1st trip DTC is detected, go to 

EC-490, "Diagnostic Procedure"

.

 With GST

Follow the procedure “With CONSULT-II” above.

Diagnostic Procedure

NBS001Z6

1. 

INSPECTION START

 With CONSULT-II

1.

Turn ignition switch ON.

2.

Select “SELF DIAG RESULTS” mode with CONSULT-II.

3.

Touch “ERASE”.

4.

Perform DTC Confirmation Procedure.
See 

EC-489, "DTC Confirmation Procedure"

 .

5.

Is the 1st trip DTC P0605 displayed again?

 With GST

1.

Turn ignition switch ON.

2.

Select “Service $04” with GST.

3.

Perform DTC Confirmation Procedure.
See 

EC-489, "DTC Confirmation Procedure"

 .

4.

Is the 1st trip DTC P0605 displayed again?

Yes or No

Yes

>> GO TO 2.

No

>> INSPECTION END

SEF058Y

SEF058Y