Hyundai Sonata LF: Emission Control System / Crankcase Emission Control System

Hyundai Sonata LF 2014-2019 Service Manual / Emission Control System / Crankcase Emission Control System

Schematic Diagrams

Schematic Diagram

Repair procedures

Inspection

1.	After disconnecting the vapor hose from the PCV valve, remove the PCV valve.

2.	Reconnect the PCV valve to the vapor hose.

Inspect the PCV vlave operation.

(1)	Run the engine at idle.

(2)	Put a finger on the open end of the PCV valve.

(3)	Make sure that intake manifold vaccum can be felt.

The plunger inside the PCV valve will move back and forth at vacuum.

4.	If the vacuum is not felt, clean or replace the vapor hose.

Positive Crankcase Ventilation (PCV) Valve Description and Operation

Operation Principle

Positive Crankcase Ventilation (PCV) Valve Repair procedures

Removal

1.	Disconnect the PCV hose (A).

2.	Remove the PCV valve (B).

Inspection

Insert a thin stick (A) into the PCV valve (B) from the threaded side to check that the plunger moves.

If the plunger does not move (PCV valve is clogged), clean or replace the valve.

Installation

Install in the reverse order of removal.

PCV Valve installation:

7.8 ~ 11.8 N.m (0.8 ~ 1.2 kgf.m, 5.8 ~ 8.7 lb-ft)

General Information

Description and Operation Description Emissions Control System consists of three major systems. • Crankcase Emission Control System prevents blow-by gas from releasing into the atmosphere...

Evaporative Emission Control System

Other information:

Hyundai Sonata LF 2014-2019 Service Manual: Troubleshooting

Trouble Symptom Charts Trouble Symptom 1 Trouble Symptom 2 Trouble symptomProbable causeRemedyThe set vehicle speed varies greatly upward or downward"Surging" (repeated alternating acceleration and deceleration) occurs after settingMalfunction of the vehicle speed sensor circuitRepair the vehicle speed sensor system, or replace the partMalfunction of ECMCheck input and output signals at ECM Trouble Symptom 3 Trouble symptomProbable causeRemedyThe CC system is not canceled when the brake pedal is depressedDamaged or disconnected wiring of the brake pedal switchRepair the harness or replace the brake pedal switchMalfunction of the ECM signalsCheck input and output signals at ECM Trouble Symptom 4 Trouble symptomProbable causeRemedyThe CC system is not canceled when the shift lever is moved to the "N" position (It is canceled, however, when the brake pedal is depressed)Damaged or disconnected wiring of inhibitor switch input circuitRepair the harness or repair or replace the inhibitor switchImproper adjustment of inhibitor switchMalfunction of the ECM signalsCheck input and output signals at ECM Trouble Symptom 5 Trouble symptomProbable causeRemedyCannot decelerate (coast) by using the "SET/–" switchTemporary damaged or disconnected wiring of "SET/–" switch input circuitRepair the harness or replace the "SET/–" switchMalfunction of the ECM signalsCheck input and output signals at ECM Trouble Symptom 6 Trouble symptomProbable causeRemedyCannot accelerate or resume speed by using the "RES/+" switchDamaged or disconnected wiring, or short circuit, or "RES/+" switch input circuitRepair the harness or replace the "RES/+" switchMalfunction of the ECM signalsCheck input and output signals at ECM Trouble Symptom 7 Trouble symptomProbable causeRemedyCC system can be set while driving at a vehicle speed of less than 40km/h (25mph), or there is no automatic cancellation at that speedMalfunction of the vehicle-speed sensor circuitRepair the vehicle speed sensor system, or replace the partMalfunction of the ECM signalsCheck input and output signals at ECM Trouble Symptom 8 Trouble symptomProbable causeRemedyThe cruise main switch indicator lamp does not illuminate (But CC system is normal)Damaged or disconnected bulb of cruise main switch indicator lampRepair the harness or replace the part...

Hyundai Sonata LF 2014-2019 Service Manual: Exhaust Emission Control System

Description and Operation Description Exhaust emissions (CO, HC, NOx) are controlled by a combination of engine modifications and the addition of special control components. Modifications to the combustion chamber, intake manifold, camshaft and ignition system form the basic control system...