To start the diesel engine when the engine is cold, it has to be pre-heated before starting the engine and then have to be warmed up before starting to drive.
1.Make sure the parking brake is applied.
2.Manual Transaxle - Depress the clutch pedal fully and shift the transaxle into Neutral. Keep the clutch pedal and brake pedal depressed while pressing the engine start/stop button to the START position.
Automatic Transaxle / DCT* - Place the transaxle shift lever in P (Park). Depress the brake pedal fully.
You can also start the engine when the shift lever is in the N (Neutral) position.

3. Press the engine start/stop button while depressing the brake pedal.
4. Continue depressing the brake pedal until the illuminated glow indicator goes off. (approximately 5 seconds)
5. The engine starts running when the glow indicator goes off.
✽ NOTICE
If the engine start/stop button is pressed once more while the engine is pre-heating, the engine may start.
Starting and stopping the engine for turbocharger intercooler
1. Do not race or accelerate the engine immediately after starting.
If the engine is cold, idle for several seconds before sufficient lubrication is ensured in the turbocharger unit.
2. After high speed or extended driving, requiring a heavy engine load, idle the engine about 1 minute before turning it off.
This idle time will allow the turbocharger to cool prior to shutting the engine off.
CAUTION
Do not turn the engine off immediately after it has been subjected to a heavy load. Doing so may cause severe damage to the engine or turbocharger unit.
WARNING
The engine will start, only when the smart key is in the vehicle.
Never allow children or any person who is unfamiliar with the vehicle touch the engine start/stop button or related parts.
CAUTION
If the engine stalls while the vehicle is in motion, do not attempt to move the shift lever to the P (Park) position. If the traffic and road conditions permit, you may put the shift lever in the N (Neutral) position while the vehicle is still moving and press the engine start/stop button in an attempt to restart the engine.

✽ NOTICE
CAUTION
Do not press the engine start/stop button for more than 10 seconds except when the stop lamp fuse is blown.
Starting the gasoline engine
ISG (Idle Stop and Go) systemKia Cee'd JD Owners Manual: Closing the tailgate
❈ The actual luggage room in the vehicle may
differ from the illustration.
Lower and push down the tailgate firmly.
Make sure that the tailgate is securely
latched.
WARNING
Make sure your hands, feet and other
parts of your body are safely out of
the way before closing the tailgate. ...
Kia Cee'd JD Service Manual: Rail Pressure Sensor (RPS) Repair procedures
Inspection
1.
Connect the GDS on the Data Link Connector (DLC).
2.
Measure the output voltage of the RPS at idle and various engine speed.
Condition
Output Voltage (V)
...