Nissan Sentra B18 (2020-2025) Service Manual: P0078 Evt Control Solenoid Valve
Dtc Description
DTC Description
DTC DETECTION LOGIC
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DTC |
CONSULT screen terms (Trouble diagnosis content) |
DTC detection condition |
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P0078 |
EX V/T ACT/CIRC-B1 (Exhaust valve control solenoid circuit bank 1) |
Diagnosis condition |
Engine running at idle |
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Signal (terminal) |
Exhaust valve timing control solenoid valve signal |
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Threshold |
An improper voltage is sent to the ECM through exhaust valve timing control solenoid valve |
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Diagnosis delay time |
— |
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POSSIBLE CAUSE
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Harness or connectors (Exhaust valve timing control solenoid valve circuit is open or shorted.)
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Exhaust valve timing control solenoid valve
FAIL-SAFE
Engine Control System
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Engine operating condition in fail-safe mode |
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|---|---|---|
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Fail safe mode |
Nissan Sentra Vehicle behavior |
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Device fix mode |
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Idle Start/Stop System
When a DTC is detected, the start/stop indicator lamp blinks slowly and the idle start/stop system operation is prohibited.
When ECM detects error while operating the idle start/stop system, ECM restarts the engine.
Confirmation Procedure
Confirmation Procedure
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PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at least 10 seconds before conducting the next test.
>>GO TO 2.
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PERFORM DTC CONFIRMATION PROCEDURE
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Start the engine and let it idle for at least 5 seconds.
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Check 1st trip DTC.
Is 1st trip DTC detected?
YES >>Proceed to DTC Diagnosis Procedure.
NO-1 >>To check malfunction symptom before repair: Refer to Intermittent Incident.
NO-2 >>Confirmation after repair: INSPECTION END
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Dtc Diagnosis Procedure
DTC Diagnosis Procedure
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CHECK DTC PRIORITY
If DTC P0078 is displayed with DTC P0090 and P1197, first perform the trouble diagnosis for DTC P0090 and P1197.
Is applicable DTC detected?
YES >>Perform diagnosis of applicable.
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DTC P0090: Refer to DTC Description.
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DTC P1197: Refer to DTC Description.
GO TO 2.
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BLEED THE FUEL LINE
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Start the engine, and let the engine run at idle at least for 10 minutes.
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Perform DTC confirmation procedure of DTC P0078.
Is 1st trip DTC detected?
YES >>GO TO 3.
NO >>GO TO 7.
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CHECK LOW FUEL PRESSURE
Check low fuel pressure. Refer to Work Procedure.
Is inspection result normal?
YES >>GO TO 4.
NO >>Check low fuel pressure system. Refer to Diagnosis Procedure.
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CHECK LOW PRESSURE FUEL LINE FOR INTERNAL LEAKAGE
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Turn ignition switch OFF.
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Turn ignition switch ON.
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Check the following value 30 minutes after turning the ignition switch ON.
Low fuel pressure
: 206 kPa (2.1 bar, 2.2 kgf/cm2, 30 psi) or more
Is inspection result normal?
YES >>GO TO 5.
NO >>Replace “fuel level sensor unit and fuel pump”. Refer to Removal and Installation.
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CHECK HIGH PRESSURE FUEL PUMP
Check high pressure fuel pump. Refer to Component Inspection.
Is inspection result normal?
YES >>GO TO 6.
NO >>Repair or replace the error-detected parts.
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CHECK HIGH PRESSURE FUEL PUMP LIFTER
Check high pressure fuel pump lifter. Refer to Removal and Installation.
Does the lifter top surface have scratches and/or dents?
YES >>Replace the error-detected parts.
NO >>INSPECTION END
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CHECK LOW PRESSURE FUEL LINE FOR INTERNAL LEAKAGE
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Turn ignition switch OFF.
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Connect fuel pressure gauge. Refer to Work Procedure.
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Turn ignition switch ON.
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Check the following value 30 minutes after turning the ignition switch ON.
Low fuel pressure
: 206 kPa (2.1 bar, 2.2 kgf/cm2, 30 psi) or more
Is inspection result normal?
YES >>INSPECTION END
NO >>Replace “fuel level sensor unit and fuel pump”. Refer to Removal and Installation.
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Other materials:
A/c Switch Assembly Signal Circuit
Diagnosis Procedure
Diagnosis Procedure
CHECK WITH SELF DIAGNOSTIC RESULT FUNCTION
CONSULT
Select “Self Diagnostic Result” mode of “HVAC”.
Check DTC.
...
Reference Value
Reference Value
TERMINAL LAYOUT
PHYSICAL VALUES
Terminal No.
(Wire color)
Description
Condition
Value
...
Intelligent Key Button Operation Has Poor Range (all Keys)
Description
Description
Intelligent Key button operation has poor
range.
SYMPTOM TABLE (BOTH INTELLIGENT KEYS HAVE
THE SAME SYMPTOMS)
Door lock operation (remote
keyless entry)
...