Nissan Xterra. Manual - part 321

EC-410

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE]

P1800 VIAS CONTROL SOLENOID VALVE 1

2.

DETECT MALFUNCTIONING PART

Check the following.

• Harness for open or short between VIAS control solenoid valve and ECM

>> Repair harness or connectors.

3.

CHECK VIAS CONTROL SOLENOID VALVE OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1. Turn ignition switch OFF.

2. Disconnect ECM harness connector.

3. Check harness continuity between ECM terminal 39 and VIAS control solenoid valve terminal 2.

Refer to Wiring Diagram.

4. Also check harness for short to ground and short to power.
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 VIAS CONTROL SOLENOID VALVE

Refer to 

EC-410, "Component Inspection"

.

OK or NG

OK

>> GO TO 5.

NG

>> Replace VIAS control solenoid valve. Refer to 

EM-25, "Exploded View"

.

5.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-40, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000009484156

VIAS CONTROL SOLENOID VALVE

 With CONSULT

1. Reconnect harness connectors disconnected.
2. Turn ignition switch ON.
3. Perform “VIAS S/V-1” in “ACTIVE TEST” mode.
4. Check air passage continuity and operation delay time under the

following conditions.

Operation takes less than 1 second.

 With GST

Continuity should exist.

Condition

VIAS SOL VALVE

Air passage continuity 

between (A) and (B)

Air passage continuity 

between (A) and (C)

ON

Yes

No

OFF

No

Yes

JMBIA0180ZZ

P1800 VIAS CONTROL SOLENOID VALVE 1

EC-411

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE]

C

D

E

F

G

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A

EC

N

P

O

Check air passage continuity and operation delay time under the fol-

lowing conditions.

Operation takes less than 1 second.

Condition

Air passage continuity 

between (A) and (B)

Air passage continuity 

between (A) and (C)

12V direct current supply 
between terminals 1 and 2

Yes

No

No supply

No

Yes

PBIB2532E

EC-412

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE]

P1805 BRAKE SWITCH

P1805 BRAKE SWITCH

Description

INFOID:0000000009484157

Brake switch signal is applied to the ECM through the stop lamp switch when the brake pedal is depressed.

This signal is used mainly to decrease the engine speed when the vehicle is being driven.

On Board Diagnosis Logic

INFOID:0000000009484158

The MIL will not illuminate for this diagnosis.

FAIL-SAFE MODE

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

DTC Confirmation Procedure

INFOID:0000000009484159

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.
1. Turn ignition switch ON.
2. Fully depress the brake pedal for at least 5 seconds.
3. Erase the DTC with CONSULT.
4. Check 1st trip DTC.
5. If 1st trip DTC is detected, go to 

EC-412, "Diagnosis Procedure"

.

Diagnosis Procedure

INFOID:0000000009484160

1.

CHECK STOP LAMP SWITCH CIRCUIT

1. Turn ignition switch OFF.

2. Check the stop lamp when depressing and releasing the brake pedal.

OK or NG

OK

>> GO TO 4.

NG

>> GO TO 2.

2.

CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT 

1. Disconnect stop lamp switch harness connector.

2. Check voltage between stop lamp switch terminal 1 and ground with CONSULT or tester.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1805
1805

Brake switch

A brake switch signal is not sent to ECM for ex-
tremely long time while the vehicle is being driv-
en.

• Harness or connectors

(Stop lamp switch circuit is open or short-
ed.)

• Stop lamp switch

Engine operating condition in fail-safe mode

ECM controls the electric throttle control actuator by regulating the throttle opening to a small range.
Therefore, acceleration will be poor.

Vehicle condition

Driving condition

When engine is idling

Normal

When accelerating

Poor acceleration

Brake pedal

Stop lamp

Fully released

Not illuminated

Slightly depressed

Illuminated

Voltage: Battery voltage

P1805 BRAKE SWITCH

EC-413

< DTC/CIRCUIT DIAGNOSIS >

[VQ40DE]

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A

EC

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OK or NG

OK

>> GO TO 4.

NG

>> GO TO 3.

3.

DETECT MALFUNCTIONING PART

Check the following.

• 10A fuse (No. 20)

• Fuse block (J/B) connector E160

• Harness for open and short between stop lamp switch and battery

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

4.

CHECK STOP LAMP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1. Disconnect ECM harness connector.

2. Disconnect stop lamp switch harness connector.

3. Check harness continuity between ECM terminal 122 and stop lamp switch terminal 2.

Refer to Wiring Diagram.

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

OK

>> GO TO 5.

NG

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

5.

CHECK STOP LAMP SWITCH 

Refer to 

EC-413, "Component Inspection"

.

OK or NG

OK

>> GO TO 6.

NG

>> Replace stop lamp switch. Refer to 

BR-19, "Exploded View"

.

6.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-40, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000009484161

STOP LAMP SWITCH

1. Disconnect stop lamp switch harness connector.
2. Check continuity between stop lamp switch terminals 1 and 2 under the following conditions.

3. If NG, adjust stop lamp switch installation, refer to 

BR-15, "Inspection and Adjustment"

, and perform step

2 again.

Continuity should exist.

Conditions

Continuity

Brake pedal: Fully released

Should not exist.

Brake pedal: Slightly depressed

Should exist.