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Infiniti Q45 (FY33). Manual - part 187

ON BOARD DIAGNOSIS LOGIC

Diagnostic

Trouble Code

No.

Malfunction is detected when ....

Check Items

(Possible Cause)

P0340
0101

A) Either 1° or 90° signal is not sent to ECM for the first

few seconds during engine cranking.

...........................................................................................

Harness or connectors
(The camshaft position sensor circuit is open or
shorted.)

Camshaft position sensor

Starter motor (Refer to EL section.)

Starting system circuit (Refer to EL section.)

Dead (Weak) battery

B) Either 1° or 90° signal is not sent to ECM during

engine running.

...........................................................................................

C) Either 1° or 90° signal is not in the normal pattern

during engine running.

DIAGNOSTIC TROUBLE CODE CONFIRMATION
PROCEDURE

Perform “Procedure for malfunction A” first. If DTC cannot be
confirmed, perform “Procedure for malfunction B and C”.
NOTE:
If “DIAGNOSTIC TROUBLE CODE CONFIRMATION PROCE-
DURE” has been previously conducted, always turn ignition
switch “OFF” and wait at least 5 seconds before conducting
the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that bat-
tery voltage is more than 10.5V at idle.

SEF400X

Procedure for malfunction A

1) Turn ignition switch “ON” and select “DATA MONITOR”

mode with CONSULT-II.

2) Start engine and run it for at least 2 seconds at idle

speed.
(If engine does not run, turn ignition switch to “START”
for at least 2 seconds.)

3) If 1st trip DTC is detected, go to “DIAGNOSTIC

PROCEDURE”, EC-279.

------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ OR ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Follow the procedure “With CONSULT-II” above.

Procedure for malfunction B and C

1) Turn ignition switch “ON”.
2) Select “DATA MONITOR” mode with CONSULT-II.
3) Start engine and run it for at least 2 seconds at idle

speed.

4) If 1st trip DTC is detected, go to “DIAGNOSTIC

PROCEDURE”, EC-279.

Follow the procedure “With CONSULT-II” above.

IDX

TROUBLE DIAGNOSIS FOR DTC P0340

Camshaft Position Sensor (CMPS) (Cont’d)

EC-277

TEC030M

TROUBLE DIAGNOSIS FOR DTC P0340

Camshaft Position Sensor (CMPS) (Cont’d)

EC-278

SEF802W

SEF377U

SEF872Q

SEF409U

SEF150T

DIAGNOSTIC PROCEDURE

INSPECTION START

CHECK STARTING SYSTEM.
Does the engine turn over?
(Does the starter motor operate?)

Yes

Check starting system.
(Refer to EL section.)

1. Turn ignition switch “OFF”.

2. Loosen and retighten engine ground

screws.

CHECK POWER SUPPLY.
1. Disconnect camshaft position sensor

harness connector.

2. Turn ignition switch “ON”.
3. Check voltage between terminal

and ground with CONSULT-II or tester.
Voltage: Battery voltage

Check the following.

Harness for open or
short between camshaft
position sensor and
ECM

Harness for open or
short between camshaft
position sensor and
ECM relay

If NG, repair open circuit or
short to ground and short
to power in harness or
connectors.

CHECK INPUT SIGNAL CIRCUIT.
1. Turn ignition switch “OFF”.
2. Disconnect camshaft position sensor

harness connector and ECM harness
connector.

3. Check harness continuity between ter-

minal

and ECM terminal

, terminal

and ECM terminals

Continuity should exist.
If OK, check harness for short to
ground and short to power.

Repair harness or connec-
tors.

CHECK GROUND CIRCUIT.
1. Turn ignition switch “OFF”.
2. Check harness continuity between ter-

minal

and engine ground.

Continuity should exist.
If OK, check harness for short to
power.

Check the following.

Harness connectors

F61

F62

If NG, repair open circuit or
short to power in harness
or connectors.

CHECK COMPONENT
[Camshaft position sensor].
Refer to “COMPONENT INSPECTION” on
next page.

Replace camshaft position
sensor.

(Go to next page.)

IDX

TROUBLE DIAGNOSIS FOR DTC P0340

Camshaft Position Sensor (CMPS) (Cont’d)

EC-279

Perform “TROUBLE DIAGNOSIS FOR
INTERMITTENT INCIDENT”, EC-117.

Trouble is not fixed.

Visually check the surface of camshaft
sprocket for chipping.

Replace camshaft sprocket.

INSPECTION END

SEF839U

COMPONENT INSPECTION

Camshaft position sensor

Start engine and warm it up to the normal operating tempera-
ture.

Check voltage between ECM terminals

(POS) or

(REF) (ECM terminal) and ground with DC range.

CAUTION:

Do not use ECM ground terminals when measuring voltage.
Doing so may result in damage to the ECM’s transistor. Use a
ground other than ECM terminals such as the body ground.

Condition

Terminals

Voltage

Engine running at idle

and ground (POS)

Approx. 2.5V

SEF547T

and ground (REF)

Approx. 0.7 - 1.2V

SEF046V

Engine at 2,000 rpm

and ground (POS)

SEF548T

and ground (REF)

SEF544T

If NG, replace camshaft position sensor.

TROUBLE DIAGNOSIS FOR DTC P0340

Camshaft Position Sensor (CMPS) (Cont’d)

EC-280

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