Nissan Xterra. Manual - part 257

EC-154

< DTC/CIRCUIT DIAGNOSIS >

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U1001 CAN COMM CIRCUIT

U1001 CAN COMM CIRCUIT

Description

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CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-

tiplex communication line with high data communication speed and excellent error detection ability. Many elec-

tronic control units are equipped onto a vehicle, and each control unit shares information and links with other

control units during operation (not independent). In CAN communication, control units are connected with 2

communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.

Each control unit transmits/receives data but selectively reads required data only.

On Board Diagnosis Logic

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The MIL will not illuminate for this diagnosis.

DTC Confirmation Procedure

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1. Turn ignition switch ON and wait at least 3 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to 

EC-154, "Diagnosis Procedure"

.

Diagnosis Procedure

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Go to 

LAN-45, "CAN System Specification Chart"

.

DTC No.

Trouble diagnosis 

name

DTC detecting condition

Possible cause

U1001
1001

CAN communication 
line

• When ECM is not transmitting or receiving 

CAN communication signal other than OBD 
(emission-related diagnosis) for 2 seconds or 
more.

• Harness or connectors

(CAN communication line is open or 
shorted)

P0011, P0021 IVT CONTROL

EC-155

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P0011, P0021 IVT CONTROL

On Board Diagnosis Logic

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FAIL-SAFE MODE

When the malfunction is detected, the ECM enters fail-safe mode.

DTC Confirmation Procedure

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CAUTION:

Always drive at a safe speed.

NOTE:

• If DTC P0011 or P0021 is displayed with DTC P0075 or P0081, first perform trouble diagnosis for DTC

P0075 or P0081. Refer to 

EC-165, "Component Description"

.

• If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at

least 10 seconds before conducting the next step. 

1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:

Before performing the following procedure, confirm that battery voltage is between 10V and 16V at

idle.

 WITH CONSULT

1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT.
2. Start engine and warm it up to the normal operating temperature.
3. Maintain the following conditions for at least 14 consecutive seconds. Hold the accelerator pedal as

steady as possible.

4. Stop vehicle with engine running and let engine idle for 10 seconds.
5. Check 1st trip DTC.
6. If the 1st trip DTC is detected, go to 

EC-156, "Diagnosis Procedure"

. 

If the 1st trip DTC is not detected, go to next step. 

7. Maintain the following conditions for at least 20 consecutive seconds.

DTC No.

Trouble diagnosis 

name

Detecting condition

Possible cause

P0011
0011
(Bank 1)

Intake valve timing 
control performance

There is a gap between angle of target and 
phase-control angle degree.

• Crankshaft position sensor (POS)
• Camshaft position sensor (PHASE)
• Intake valve timing control solenoid valve
• Accumulation of debris to the signal pick-up 

portion of the camshaft

• Timing chain installation
• Foreign matter caught in the oil groove for in-

take valve timing control

P0021
0021
(Bank 2)

Detected items

Engine operating condition in fail-safe mode

Intake valve timing control

The signal is not energized to the solenoid valve and the valve control does not function.

ENG SPEED

1,200 - 2,000 rpm

COOLAN TEMP/S

More than 60

°C (140°F)

B/FUEL SCHDL

More than 3.5 msec

Selector lever

P or N position (A/T)
Neutral position (M/T)

EC-156

< DTC/CIRCUIT DIAGNOSIS >

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P0011, P0021 IVT CONTROL

8. Check 1st trip DTC.
9. If the 1st trip DTC is detected, go to 

EC-156, "Diagnosis Procedure"

.

 WITH GST

Follow the procedure “WITH CONSULT” above.

Diagnosis Procedure

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1.

CHECK OIL PRESSURE WARNING LAMP

1. Start engine.

2. Check oil pressure warning lamp and confirm it is not illumi-

nated.

OK or NG

OK

>> GO TO 2.

KG

>> Go to 

LU-7, "Inspection"

.

2.

CHECK INTAKE VALVE TIMING CONTROL SOLENOID VALVE

Refer to 

EC-157, "Component Inspection"

.

OK or NG

OK

>> GO TO 3.

NG

>> Replace malfunctioning intake valve timing control solenoid valve. Refer to 

EM-28, "Exploded

View"

.

3.

CHECK CRANKSHAFT POSITION SENSOR (POS)

Refer to 

EC-277, "Component Inspection"

.

OK or NG

OK

>> GO TO 4.

NG

>> Replace crankshaft position sensor (POS). Refer to 

TM-250, "Removal and Installation (2WD)"

(5AT), 

TM-21, "Removal and Installation from Vehicle"

 (6MT).

4.

CHECK CAMSHAFT POSITION SENSOR (PHASE)

Refer to 

EC-280, "Component Inspection"

.

OK or NG

OK

>> GO TO 5.

NG

>> Replace malfunctioning camshaft position sensor (PHASE). Refer to 

EM-59, "Exploded View"

.

5.

CHECK CAMSHAFT (INTAKE)

Check the following.

ENG SPEED

1,700 - 3,175 rpm (A constant rotation is maintained.)

COOLAN TEMP/S

More than 70

°C (158°F)

Selector lever

1st or 2nd position

Driving location uphill

Driving vehicle uphill
(Increased engine load will help maintain the driving 
conditions required for this test.)

PBIA8559J

P0011, P0021 IVT CONTROL

EC-157

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• Accumulation of debris on the signal plate of camshaft rear end

• Chipping signal plate of camshaft rear end
OK or NG

OK

>> GO TO 6.

NG

>> Remove debris and clean the signal plate of camshaft

rear end or replace camshaft. Refer to 

EM-75,

"Exploded View"

.

6.

CHECK TIMING CHAIN INSTALLATION

Check service records for any recent repairs that may cause timing chain misalignment.

Are there any service records that may cause timing chain misalignment?
Yes or No

Yes

>> Check timing chain installation. Refer to 

EM-59, "Removal and Installation"

.

No

>> GO TO 7.

7.

CHECK LUBRICATION CIRCUIT

Refer to 

LU-6, "Lubrication Circuit"

.

OK or NG

OK

>> GO TO 8.

NG

>> Clean lubrication line.

8.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-40, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

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INTAKE VALVE TIMING CONTROL SOLENOID VALVE

1. Disconnect intake valve timing control solenoid valve harness connector.
2. Check resistance between intake valve timing control solenoid valve as follows.

If NG, replace intake valve timing control solenoid valve. Refer to 

EM-59, "Exploded View"

.

If OK, go to next step.

3. Remove intake valve timing control solenoid valve.

4. Provide 12V DC between intake valve timing control solenoid

valve terminals and then interrupt it. Check that the plunger

moves as shown in the figure.

CAUTION:

Never apply 12V DC continuously for 5 seconds or more.

Doing so may result in damage to the coil in intake valve

timing control solenoid valve.

If NG, replace intake valve timing control solenoid valve.

NOTE:

Always replace O-ring when intake valve timing control

solenoid valve is removed.

SEC905C

Terminal

Resistance

1 and 2

7.0 - 7.7

Ω at 20°C (68°F)

1 or 2 and ground

∞Ω

(Continuity should not exist.)

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