Kia Optima Hybrid: Engine Control System / NVLD(Natural Vacuum Leakage Detection) Description and Operation

Kia Optima Hybrid (TF HEV) 2016-2020 Service Manual / Engine Control/Fuel System / Engine Control System / NVLD(Natural Vacuum Leakage Detection) Description and Operation

Description

NVLD(Natural Vacuum Leakage Detection) is located between the canister and the fuel tank air filter. NVLD is to detect leaks equivalent to a 0.5 mm hole in the fuel tank, canister and hoses. When the engine has been running, the temperature of the fuel in the fuel tank is raised slightly. When the engine is shut off, the temperature of the fuel should drop. The ideal gas law states that in a sealed system the pressure drops proportionately to a drop in temperature.

[No leak]

[With 0.5mm leak]

While the engine is shut off, ECM monitors a pressure switch that is built into the NVLD for detecting slight drop in pressure. If the switch change is not detected after an engine shut down, it assumes there is a leak in the sealed system.

CVVT Oil Control Valve (OCV) Repair procedures

Inspection 1. Turn the ignition switch OFF. 2. Disconnect the OCV connector. 3. Measure resistance between the OCV terminals 1 and 2. 4. Check that the resistance is within the specification. Specification: ...

NVLD(Natural Vacuum Leakage Detection) Specifications

Specification Pressure [kPa (kgf/cm?, in H2O)Output Voltage (V)-6.67 (-0.068, -26.8)0.502.5+6.67 (0.068, 26.8)4.5 ...

Other information:

Kia Optima Hybrid (TF HEV) 2016-2020 Service Manual: Troubleshooting

Trouble Shooting Ignition System SymptomSuspect areaRemedyVehicle indicates Ready in dash, but engine will not run when requested by the HPCU (HEV module).Ignition coilInspect ignition coil, or replace as requiredSpark plugsInspect spark plugs, or replace as requiredIgnition wiring disconnected or brokenRepair ...

Kia Optima Hybrid (TF HEV) 2016-2020 Service Manual: Schematic Diagrams

System Block Diagram Component Parts And Function Outline Component partFunctionECUControls engine.MCUControls drive motor.ABSSends vehicle speed to HCU.HCUReceives signals from sensor and control switches.Cluster (Cruise control indicator)Illuminate when CRUISE main switch is ON (Built into cluster)Cruise ...