Kia Optima DL3 Quiz

Engine Control System/Fuel System

In this manual: Engine Control System/Fuel System
General Information — 8Advanced Driver Assistance System (ADAS) — 21Maintenance — 27Engine Mechanical System — 45Engine Electrical System — 11Emission Control System — 11Engine Control System/Fuel System — 25Automatic Transmission — 20Drive Shaft and Axle — 7Suspension System — 22Steering — 7Restraints — 11Brake System — 22Body (Interior and Exterior) — 116Body Electrical System — 90Heating, Ventilation, and Air Conditioning — 32
59steps
~374min
5/5difficulty
4special tools
Done 0 of 59

Service Data

Service Data

Sensor

Manifold Absolute Pressure (MAP) Sensor

Pressure Output voltage (V)
kPa kgf/cm² psi
20 0,2 2,9 0,79
46,7 0,47 6,77 1,84
106,7 1,03 14,7 4.2

Intake Air Temperature Sensor (IATS)

Temperature [()] Resistance (kOhm)
°C °F
-40 -40 40,93 - 48,35
-20 -4 13.89 - 16.03
0 32 5.38 - 6.09
10 50 3,48 - 3,90
20 68 2,31 - 2,57
40 104 1,08 - 1,21
50 122 0,76 - 0,85
60 140 0,54 - 0,62
80 176 0,29 - 0,34

Engine Coolant Temperature Sensor (ECTS)

Temperature Resistance (kOhm)
°C °F
45 113 244,8 - 281,4
55 131 162,5 - 186,5
60 140 133,5 - 153,5
71 159,8 88,93 - 102,13
85 185 55,16 - 63,36
110 230 26.02 - 29.82
125 257 17,5 - 19,7

Throttle Position Sensor (TPS) [Built into ETC Module]

Throttle Angle (°) Output Voltage (V) [Vref = 5.0 V]
TP1 TP2
0 0,5 4,5
10 0,96 4.05
20 1,41 3,59
30 1,87 3.14
40 2,32 2,68
50 2,78 2,23
60 3,23 1,77
70 3,69 1,32
80 4.14 0,86
90 4.6 0,41
98 4,65 0,35
THA (0) 0,5 4,5
THW (86) 4.41 0,59

Accelerator Pedal Position Sensor (APS)

Accelerator Position Output Voltage (V) [Vref = 5.0 V]
VPA1 VPA2
THA 0,7 - 0,8 0,33 - 0,43
THW 3,98 - 4,22 1,93 - 2,17

Knock Sensor (KS)

Item Specification
Capacitance (pF) 850 - 1150

Actuator

Injector

Item Specification
Coil Resistance (Ω) 14,5 [20 °C]

ETC Motor [Built into ETC Module]

Item Specification
Coil Resistance (Ω) 0,3–100 [20 °C]

CVVT Oil Control Valve (OCV)

Item Specification
Coil Resistance (Ω) 9,4–10,4 [20 °C]

Variable Intake Solenoid (VIS) Valve

Item Specification
Coil Resistance (Ω) 30,0–35,0 [22 °C]

Fuel Delivery System

Items Specification
Fuel tank Capacity 60 L (15.8 U.S. gal, 63.4 U.S. qt, 52.8 Imp. qt)
Fuel filter Type Paper Type
Fuel Pressure Regulator Regulated Fuel Pressure 330 - 370 kPa (3.3 - 3.7 bar, 3.365 - 3.772 kgf/cm²)
Fuel pump Type Electric, In-Tank Type
Which was driven Electric Motor

Tightening Torque

Tightening Torque

Engine Control System

Item N·m kgf·m lbf·ft
ECM Module and Bracket Bolts 9,8 - 11,8 1,0 - 1,2 7,2 - 8,7
Electronic Throttle Body Bolts 7,8 - 11,8 0,8 - 1,2 5,8 - 8,7
Manifold Absolute Pressure Sensor Mounting Bolt 9,8 - 11,8 1,0 - 1,2 7,2 - 8,7
Engine Coolant Temperature Sensor 29,4 - 39,2 3,0–4,0 21,7 - 28,9
Crankshaft Position Sensor Mounting Bolt 9,8 - 11,8 1,0 - 1,2 7,2 - 8,7
Camshaft Position Sensor Bolt 9,8 - 11,8 1,0 - 1,2 7,2 - 8,7
Knock Sensor Mounting Bolt 18,6 - 23,5 1,9 - 2,4 13,7 - 17,4
Heated Oxygen Sensor 39,2 - 49,1 4,0–5,0 28,9 - 36,2
Accelerator Pedal Module Nuts 6,9 - 10,7 0,7 - 1,1 5,0 - 7,9
CVVT Oil Control Valve Bolt 9,8 - 11,8 1,0 - 1,2 7,2 - 8,7
Variable Intake Solenoid Valve Bolts 9,8 - 11,8 1,0 - 1,2 7,2 - 8,7
Variable Charge Actuator Bolts 9,8 - 11,8 1,0 - 1,2 7,2 - 8,7

Fuel Delivery System

Item N·m kgf·m lbf·ft lbf·ft
Fuel Tank Band Bolt 39,2 - 54,0 4,0 - 5,5 28,9 - 39,8 -
Filler Hose Clamp 4,9 - 5,9 0,5 - 0,6 3,6 - 4,3 43.40 - 52.08
Filler Neck Bracket Mounting Bolt 8,8 - 9,8 0,9 - 1,0 6,5 - 7,2 -
Delivery Pipe Mounting Bolt 18,6 - 23,5 1,9 - 2,4 13,7 - 17,4 -

Special Service Tools

Special Service Tools

Tool Name/Number Illustration Description
Fuel Pressure Sensor
09353-24100
Used to measure the fuel rail pressure.
Fuel Pressure Sensor Adapter
09353-02100
Used to connect the delivery pipe and the fuel feed line.
Heated Oxygen Sensor Socket Wrench
09392-1Y100
Used to remove/install the heated oxygen sensor

※ SST No. 09392-2H100 can also be used to remove the heated oxygen sensor.
Fuel Pump Cover Wrench
09310-B8100
Fuel Pump Plate Cover Removal and Installation

Troubleshooting

Basic Troubleshooting Procedures

Basic Troubleshooting Procedure Guide

Basic Inspection Procedure

Electronic Component Resistance Measurement Conditions

Measured resistance may be high or low when the vehicle is at high temperature after driving. Therefore, all resistance values must be measured at ambient temperature (20 °C, 68°F) unless otherwise specified.

Intermittent Problem Inspection Procedure

Sometimes the most difficult case in troubleshooting is when the symptom occurs but cannot be reproduced during testing. For example, if the problem appears only when the vehicle is cold but not when it is warm. In this case, the technician should carefully complete the Customer Problem Analysis Sheet and try to recreate (simulate) the environment and conditions present when the problem occurred.

  1. Clear the Diagnostic Trouble Code (DTC).

  2. Inspect the connector and check the terminals for poor contact, loose wires, bent, broken or corroded contacts, then make sure all connectors are always securely fastened.

  3. Gently shake the connector and wire harness vertically and horizontally.

  4. Repair or replace the faulty component.

  5. Confirm that the problem is resolved by performing a road test.

● Simulate vibration

a.

Sensors and Actuators

: Lightly tap the sensors, actuators, or relays with a finger.
b.

Connectors and Harness

: Lightly shake the connector and wiring harness vertically, then horizontally.

● Simulate heat

a.

Heat the components suspected of causing the malfunction using a hair dryer or other heat source.

● Simulate water spray

a.

Spray water on the vehicle to simulate a rainy day or high humidity condition.

● Simulate electrical load

a.

Turn on all electrical systems to simulate excessive electrical loads (radio, blower fans, headlights, rear window defogger, etc.).

Connector Inspection Procedure

  1. Connector Handling

    a.

    Never pull on the wire harness when disconnecting connectors.
    b.

    When disconnecting a connector with a lock, press or pull the locking lever.
    b.

    Listen for a click when connectors lock. This sound indicates they are securely locked.
    d.

    When using a tester to check continuity or measure voltage, always insert the tester probe from the wire harness side.
    e.

    Check waterproof connector terminals from the connector side. Waterproof connectors cannot be accessed from the wire harness side.

  2. Connector Checkpoints

    a.

    While the connector is connected:

    While holding the connector, check the connection condition and lock effectiveness.
    b.

    When the connector is disconnected:

    Check for a missing terminal, crimped terminal, or broken wire by gently pulling on the wiring harness.

    Visually check for rust, contamination, deformation, and bending.
    b.

    Check the terminal tightening condition:

    Insert a spare plug into the socket, then check the terminal tightening condition.
    d.

    Gently pull on individual wires to make sure each wire is secured in the terminal.

  3. Connector Terminal Repair Method

    a.

    Clean the contact points using compressed air and/or a cloth.
    b.

    If contact pressure is abnormal, replace the female terminal.

Wire Harness Inspection Procedure

  1. Before removing the harness, check the harness position and clamps so that it can be reinstalled correctly.

  2. Check that the wire harness is not twisted, stretched or loose.

  3. Check that the wire harness is not exposed to excessive temperature.

  4. Check whether the harness is rotating, moving, or vibrating, or whether it contacts a sharp edge of a part.

  5. Check the connection between the wire harness and any installed part.

  6. If the harness covering is damaged, secure, repair or replace the harness.

Electrical Circuit Inspection Procedure

● Check for open circuit

  1. Open Circuit Procedures

    • Continuity Check

    • Voltage Check

    If an open circuit occurs (as shown in [FIG. 1]), it can be located by performing Step 2 (continuity check method) or Step 3 (voltage check method), as shown in the figures below.

  2. Continuity Check Method

    Specification (Resistance)

    1 Ω or less → Normal circuit

    1 MΩ or more → Open circuit

    a.

    Disconnect connectors (A) and (C), then measure the resistance between connector (A) and (C), as shown in [FIG. 2].

    In [FIG. 2], the measured resistance of lines 1 and 2 is more than 1 MΩ and less than 1 Ω, respectively. Therefore, the open circuit is line 1 (line 2 is normal). To find the exact break point, check the sub-line of line 1 as described in the next step.
    b.

    Disconnect connector (B) and measure the resistance between connector (C) and (B1), and between (B2) and (A), as shown in [FIG. 3].

    In this case, the measured resistance between connector (C) and (B1) is more than 1 MΩ, and there is an open circuit between terminal 1 of connector (C) and terminal 1 of connector (B1).

  3. Voltage Check Method

    a.

    With each connector still connected, measure the voltage between chassis ground and terminal 1 of each connector (A), (B), and (C), as shown in [FIG. 4].

    The measured voltages of each connector are 5 V, 5 V, and 0 V, respectively. Therefore, there is an open circuit between connectors (C) and (B).

● Check for short circuit

  1. Short to Ground Check Method

    • Continuity Check with Chassis Ground

    If a short to ground occurs (as shown in [FIG. 5]), the fault location can be found by performing Step 2 (continuity check method with ground) as shown below.

  2. Continuity Check Method (with Chassis Ground)

    Specification (Resistance)

    1 Ω or less → Short to ground

    1 MΩ or more → Normal circuit

    a.

    Disconnect connectors (A) and (C), then measure the resistance between connector (A) and body ground, as shown in [FIG. 6].

    In this example, the measured resistance of lines 1 and 2 is less than 1 Ω and more than 1 MΩ, respectively. Therefore, the short to ground is line 1 (line 2 is normal). To find the exact damaged point, check the sub-line of line 1 as described in the next step.
    b.

    Disconnect connector (B) and measure the resistance between connector (A) and chassis ground, and between (B1) and chassis ground, as shown in [FIG. 7].

    The measured resistance between connector (B1) and chassis ground is 1 Ω or less. There is a short to ground between terminal 1 of connector (C) and terminal 1 of connector (B1).

● Voltage Drop Check

This test checks the voltage drop across a wire or through a connection or switch.

A.

Connect the positive lead of the voltmeter to the end of the wire (or the connector or switch side) closest to the battery.
B.

Connect the negative lead to the other end of the wire (or the other side of the connector or switch).
C.

Operate the circuit.
D.

The voltmeter will display the voltage difference between two points. A difference or drop of more than 0.1 V (50 mV in 5 V circuits) may indicate a problem. Check the circuit for loose or dirty connections.

Symptom Troubleshooting Chart

Main Symptom Diagnostic Procedure Also check
Cannot Start
(Engine does not crank)

  1. Check the battery.

  2. Test the starter motor.

  3. Inhibitor switch (A/T) or clutch start switch (M/T)
Cannot Start
(Incomplete combustion)

  1. Check the battery.

  2. Check the fuel pressure

  3. Check the ignition circuit.

  4. Immobilizer System Troubleshooting

    (If the immobilizer lamp is flashing)

  • Trouble Code

  • Low compression

  • Intake air leaks

  • Slipping or broken timing belt

  • Contaminated Fuel
Hard to Start

  1. Check the battery.

  2. Check the fuel pressure

  3. Check the ECT sensor and circuit (check DTC)

  4. Check the ignition circuit.

  • Trouble Code

  • Low compression

  • Intake air leaks

  • Contaminated Fuel

  • Weak ignition spark
Poor Idling
(Rough, unstable or incorrect idle)

  1. Check the fuel pressure.

  2. Check the injector.

  3. Check the long-term fuel trim and short-term fuel trim.

    (Refer to CUSTOMER DATA FLOW)

  4. Check the idle air control circuit (check DTC).

  5. Inspect and check the throttle body

  6. Check the ECT sensor and circuit (check DTC)

  • Trouble Code

  • Low compression

  • Intake air leaks

  • Contaminated Fuel

  • Weak ignition spark
Engine Stalls

  1. Check the battery.

  2. Check the fuel pressure.

  3. Check the idle air control circuit (check DTC).

  4. Check the ignition circuit.

  5. Check the CKPS circuit (check DTC)

  • Trouble Code

  • Intake air leaks

  • Contaminated Fuel

  • Weak ignition spark
Poor Driveability
(Surging)

  1. Check the fuel pressure.

  2. Inspect and check the throttle body

  3. Check the ignition circuit.

  4. Check the ECT sensor and circuit (check DTC)

  5. Inspect the exhaust system for possible blockage.

  6. Check the long-term fuel trim and short-term fuel trim.

    (Refer to CUSTOMER DATA FLOW)

  • Trouble Code

  • Low compression

  • Intake air leaks

  • Contaminated Fuel

  • Weak ignition spark
Knock

  1. Check the fuel pressure.

  2. Inspect the engine coolant.

  3. Inspect the radiator and the electric cooling fan.

  4. Check the spark plugs.

  • Trouble Code

  • Contaminated Fuel
Poor Fuel Economy

  1. Check the customer's driving habits.

    · Is the air conditioner running continuously or is the defroster mode on?

    · Is the tire pressure correct?

    · Is an excessively heavy load being carried?

    · Is acceleration too strong or too frequent?

  2. Check the fuel pressure.

  3. Check the injector.

  4. Check the exhaust system for possible blockage

  5. Check the ECT sensor and circuit

  • Trouble Code

  • Low compression

  • Intake air leaks

  • Contaminated Fuel

  • Weak ignition spark
Hard to Refuel
(Overflow during refueling)

  1. Inspect the fuel tank hose/tube.

    · Is it pinched, kinked, or blocked?

    · Is the filler hose torn?

  2. Inspect the fuel tank vapor hose between the EVAP canister and the air filter

  3. Check the EVAP canister

  • Defective fuel filler nozzle at gas station (If this problem occurs at a specific gas station during refueling)

Test yourself

A quick Kia Optima DL3 quiz: every answer comes with an explanation and a link to the manual page.