YMMS: 2018 Kia Niro EX Feb 25, 2025

Engine: 1.6L Eng License:

VIN: Odometer:

General Safety Information And Caution

Safety Precaution

Precautions To Take Before Servicing High Voltage System

WARNING: Hybrid vehicles have high voltage batteries.

Incorrect handling of high voltage system or vehicle may lead to
serious accident including electric shock and electric leakage.

WARNING:

Be sure to shut off the high voltage by removing the safety

plug before performing inspection or repairing the high voltage
system.(Refer to "HIGH VOLTAGE SHUT-OFF PROCEDURES")
Keep the safety plug completely removed to prevent the plug
from being connected by mistake.
Do not wear metallic objects (watch, ring etc.) while working
on the high voltage system, due to risk of serious accidents like
electric shock.
Whenever working on the high voltage system, wear personal
protective equipment to prevent accidents. (Refer to
"PERSONAL PROTECTIVE EQUIPMENT")
Technicians not wearing personal protective equipment must
not be allowed to work on high voltage systems. Cover high
voltage components with an insulated sheet to prevent
accidents.
Use insulation tools when working on the high voltage system.
Put the removed high voltage components on the insulation
mat.

Information

All the high voltage wiring and connectors are orange.

A caution label for high voltage is attached to the high voltage components.
High voltage components include:
High Voltage Battery Pack Assembly, Power Relay Assembly (PRA), BMS ECU, Hybrid Power Control
Unit (HPCU), Hybrid Drive Motor, HSG, Electric A/C Compressor, Low DC/DC Converter (LDC), Power
Cable, Electric Compressor, etc.
 CAUTION:

To prevent injury to technician, place "High Voltage" caution

sign as shown.

Fig 1: High Voltage Caution (1 Of 2)

Courtesy of KIA MOTORS AMERICA, INC.

Fig 2: High Voltage Caution (2 Of 2)

Courtesy of KIA MOTORS AMERICA, INC.

Personal Protective Equipment

Name Illustration Description

Insulation Used when inspecting or working on the high voltage components
gloves [Insulation performance: 1000V/300A or above]

Courtesy of KIA MOTORS

AMERICA, INC.

Insulation
shoes
Courtesy of KIA MOTORS
AMERICA, INC.

Insulation Used when inspecting or working on the high voltage components

clothes

Courtesy of KIA MOTORS

AMERICA, INC.

Insulation
helmet
Courtesy of KIA MOTORS
AMERICA, INC.

Used in the following cases:

During removal & installation or inspection of the high voltage

battery terminals or wiring, where spark might happen.
Safety When working on the high voltage battery pack assembly.
glasses
Courtesy of KIA MOTORS
AMERICA, INC.
 Face shield

Courtesy of KIA MOTORS

AMERICA, INC.

Insulation All removed high voltage components are placed on an insulation mat to
mat prevent accident.
Courtesy of KIA MOTORS
AMERICA, INC.

Insulation Insulation sheet is used to cover high voltage components to protect

sheet people not wearing personal protective equipment from accident.
Courtesy of KIA MOTORS
AMERICA, INC.

Warning tape Used for informing that it is dangerous past this line.
Courtesy of KIA MOTORS
AMERICA, INC.

Personal Protective Equipment Inspection

Check that the personal protective equipment is not damaged.

Check that the insulation gloves are not torn or damaged.
Wear the insulation glove after removing moisture.

Information
Fig 3: Inspecting Personal Protective Equipment

Courtesy of KIA MOTORS AMERICA, INC.

(1) Fold the insulation glove as above.

(2) Fold again 3~4 times to make it airtight.
(2) Squeeze the inflated glove to see if the glove is torn or damaged.

Precautions To Take When Handling Power Cable

Immediately insulate the high voltage terminal after reconnecting the terminal (use insulation tape).
Tighten the high voltage terminal screw to torque specifications.
Be careful that (+) and (-) terminals do not come in contact when connecting or disconnecting power
cable and busbar.

Precautions To Take When Handling (High Voltage Battery)

When transporting high voltage battery, be sure to keep it flat and leveled. Failure to do so may decrease
the battery performance and/or its lifespan.
High voltage battery's performance may decrease if it is exposed to high temperature for a lengthy period.
As a result, heat-treatment after painting must not exceed 70°C (158°F)/30 minutes, or 80°C (176°F)/20
minutes.

Precautions In Case Of Fire On (High Voltage Battery) System

If the fire occurs indoor, ventilate the area to let out hydrogen gas.
ABC fire extinguisher is recommended for putting out the fire. (water may also be used).

Precautions In Case Of (High Voltage Battery) Gas Or Electrolyte Leakage

Turn OFF the Start button. Keep the Smart Key at least 2 meters (78.7 inch, 6.5 feet) away from the
vehicle to prevent unintended engine start.
Gas is hydrogen and alkaline vapor. If the leakage is indoor, ventilate the area immediately and evacuate
to a safe location.
If the leaked liquid comes in contact with skin, immediately neutralize the affected area with boric acid
solution, then clean with tap water or saline solution.
If the leaked vapor or liquid gets in the eye, immediately clean the affected eye with water then get
medical attention.
If the gas leakage is caused by high temperature, then do NOT use the battery until the high voltage
battery fully cools down to room temperature.

Precautions When Handling The Vehicle After An Accident

Be sure to wear insulated gloves (or rubber gloves), protective goggles, insulated suit, and insulated
boots.
Do NOT touch bare cable under any condition (refer to "PRECAUTIONS WHEN HANDLING POWER
CABLE.")
 In case of vehicle fire, put out the fire with ABC extinguisher. Do NOT use water (usage of large volume of
water is okay, but small volume can worsen the situation).
If more than half of the vehicle is submerged, then do NOT go near the Safety Switch or other high
voltage related components. If such a component must be accessed, then move the vehicle to the safe
location first before handling the component.
Gas is hydrogen and alkaline vapor. If the leakage is indoor, ventilate the area immediately and evacuate
to a safe location.
If the leaked liquid comes in contact with skin, immediately neutralize the affected area with boric acid
solution, then clean with tap water or saline solution.
Refer to "HIGH VOLTAGE SHUT-OFF PROCEDURES" if the high voltage needs to be cut off.

Preparations When Servicing The Accident Vehicle

Be sure to wear insulated gloves (or rubber gloves), protective goggles, insulated suit, and insulated
boots.
Boric acid power or solution
ABC Extinguisher
Towel for cleaning electrolyte
Vinyl tape (for insulating terminal)
Mega ohm tester (for checking high voltage)

Precautions In Case HEV Is Left Unattended For A Lengthy Period

Turn OFF the Start button. Keep the Smart Key at least 2 meters (78.7 inch, 6.5 feet) away from the
vehicle to prevent unintended engine start.
We recommend that HEV is driven at least 1 time for over 30 minutes every 2 months to protect and
manage the high voltage battery (inquire at relevant team in HMC).
When inspecting or exchanging the auxiliary battery, check high voltage battery SOC reset related
problems.

Service Standard

SERVICE STANDARD

Item Specification

Ignition Timing (°) BTDC 5° ± 10°

Neutral, N, P-range 630 ± 100

A/C OFF
D-range 630 ± 100
Idle Speed (rpm)
Neutral, N, P-range 700 ± 100
A/C ON
D-range 680 ± 100

Repair Procedures

Removal

WARNING: In case of removing the high pressure fuel pump,

high pressure fuel pipe, delivery pipe, and injector, there may be
injury caused by leakage of the high pressure fuel. So don't do any
repair work right after engine stops.
1. Release the residual pressure in fuel line.
(Refer to the Fuel Delivery System -"RELEASE RESIDUAL PRESSURE IN FUEL LINE").

2. Switch "OFF" the ignition and disconnect the negative (-) terminal of the auxiliary 12V battery.

3. Remove the intake manifold.

(Refer to Engine Mechanical System - " INTAKE MANIFOLD ")

4. Remove the high pressure pipe flange nuts (A) by using the special service tool [SST No. 09314 - 3Q100 or
09314 - 27130].

5. Remove the high pressure fuel pipe (C) after loosening the function block mounting bolt (B).
High Pressure Fuel Pipe Function Block Mounting Bolt:
9.8 - 11.8 N.m (0.8 - 1.2 kgf.m, 7.2 - 8.7 lb.ft)
High Pressure Fuel Pipe Flange Nut:
32.4 - 35.3 N.m (3.3 - 3.6 kgf.m, 23.9 - 26.0 lb.ft)
Fig 4: Removing High Pressure Pipe Flange Nuts

Courtesy of KIA MOTORS AMERICA, INC.

6. Remove the delivery pipe & injector assembly mounting bolts (A).
Delivery pipe & injector assembly mounting bolt:
18.6 - 23.5 N.m (1.9 - 2.4 kgf.m, 13.7 - 17.4 lb.ft)
 Fig 5: Removing Delivery Pipe & Injector Assembly Mounting Bolts

Courtesy of KIA MOTORS AMERICA, INC.

7. Remove the delivery pipe & injector assembly (A) from the engine.
Fig 6: Removing Delivery Pipe & Injector Assembly From Engine (1 Of 2)

Courtesy of KIA MOTORS AMERICA, INC.

 Fig 7: Removing Delivery Pipe & Injector Assembly From Engine (2 Of 2)

Courtesy of KIA MOTORS AMERICA, INC.

Installation

NOTE:

Do not reuse injector fixing clips.

Install the component to the specified torque.
Note that internal damage may occur when the component is
dropped. In this case, use it after inspecting.
Apply engine oil to the injector O-ring.
Do not reuse injector o-rings.
Do not reuse bolts.
 When inserting the injector, be careful not to damage the
injector tip.

1. Install in the reverse order of removal.

Basic Inspection Procedure

Measuring Condition of Electronic Parts' Resistance

The measured resistance at high temperature after vehicle running may be high or low. So all resistance must
be measured at ambient temperature (20°C, 68°F), unless stated otherwise.

NOTE: The measured resistance except at ambient temperature

(20°C, 68°F) is the reference value.

Intermittent Problem Inspection Procedure

Sometimes the most difficult case in troubleshooting is when a problem symptom occurs but does not reoccur
during test. An example would be if a problem appears only when the vehicle is cold but has not appeared
when warm. In this case, the technician should thoroughly make out a "Customer Problem Analysis Sheet" and
recreate (simulate) the environment and condition in which the vehicle was having the issue.

1. Clear Diagnostic Trouble Code (DTC).

2. Inspect all connections, check terminal for poor connections, loose wires, bent, broken or corroded pins,
and then verify that the connectors are securely fastened at all times.
 Fig 8: Checking Terminal For Poor Connections

Courtesy of KIA MOTORS AMERICA, INC.

3. Lightly shake the connector and wiring harness vertically and horizontally.

4. Repair or replace the component with a problem.

5. Perform road test to verify that the problem has disappeared.

Simulating Vibration

a. Sensors and Actuators

: Lightly shake sensors, actuators or relays by finger.
 WARNING: Strong vibration may break sensors, actuators or
relays.

b. Connectors and Harness

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

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

WARNING:
a. DO NOT heat components to the point of damaging them.
b. DO NOT heat the ECM directly.

Simulating Water Sprinkling

a. Sprinkle water onto vehicle to simulate a rainy day or a high humidity condition.

WARNING: DO NOT sprinkle water directly onto the engine

compartment or electronic components.

Simulating Electrical Load

a. Turn on all electrical systems to simulate an excessive electrical load (Radios, fans, lights, rear window
defogger, etc.).

Connector Inspection Procedure

1. Handling of Connector

a. Never pull on the wiring harness when disconnecting connectors.

 Fig 9: Caution For Disconnecting Connectors

Courtesy of KIA MOTORS AMERICA, INC.

b. When removing the connector with a latch, press or pull locking lever.
 Fig 10: Pulling Locking Lever

Courtesy of KIA MOTORS AMERICA, INC.

c. Listen for a click when locking connectors. This sound indicates that they are securely locked.
 Fig 11: Listening For Click Locking Connectors

Courtesy of KIA MOTORS AMERICA, INC.

d. When a tester is used to check for continuity, or to measure voltage, always insert tester probe from wire
harness side.
Fig 12: Caution For Inserting Tester Probe From Wire Harness Side

Courtesy of KIA MOTORS AMERICA, INC.

e. Check waterproof connector terminals from the connector side. Waterproof connectors cannot be
accessed from harness side.
 Fig 13: Caution For Checking Waterproof Connector Terminals From Connector Side

Courtesy of KIA MOTORS AMERICA, INC.

NOTE:
1. Use a fine wire to prevent damaging the terminal.
2. Do not damage the terminal when inserting the tester lead.

2. Checking Point for Connector

a. While the connector is connected:

Hold the connector, and check connecting condition and locking efficiency.

b. When the connector is disconnected:

Check for missing terminal, crimped terminal or broken core wire by lightly pulling the wire harness.
Visually check for rust, contamination, deformation and bending.

c. Check terminal tightening condition:

Insert a spare male terminal into a female terminal, and then check terminal tightening conditions.

d. Pull lightly on individual wires to ensure that each wire is secured in the terminal.
 Fig 14: Pulling Lightly On Individual Wires

Courtesy of KIA MOTORS AMERICA, INC.

3. Connector Terminal Repairing Method

a. Clean the contact points using air gun and/or shop rag.

NOTE: Never use sand paper when polishing the contact

points, otherwise the contact point may be damaged.

b. In case of abnormal contact pressure, replace the female terminal.

Customer Problem Analysis Sheet

Fig 15: Customer Problem Analysis Sheet

Courtesy of KIA MOTORS AMERICA, INC.

Electrical Circuit Inspection Procedure

Open Circuit Test

1. Procedures for Open Circuit

1. Continuity Check
2. Voltage Check
If an open circuit occurs (as seen in [Fig 16]), it can be found by performing 2 (Continuity Check Method) or
Step 3 (Voltage Check Method) as shown below.
 Fig 16: Checking Open Circuit

Courtesy of KIA MOTORS AMERICA, INC.

2. Continuity Check Method

NOTE: When measuring the resistance, lightly shake the wire

harness vertically or horizontally.

Specification (Resistance)
1Ω or less → Normal Circuit
1MΩ or Higher → Open Circuit

a. Disconnect connectors (A) and (C), and measure resistance between connectors (A) and (C) as shown
in [Fig 17].
In [Fig 17], if the measured resistances in lines 1 and 2 are "over 1 MΩ" and "below 1 Ω" respectively,
line 1 has an open circuit. (Line 2 is normal.) To find the exact broken point, check the sub line of line 1
as described in the next step.
 Fig 17: Measuring Resistance Between Connectors (A) And (C)

Courtesy of KIA MOTORS AMERICA, INC.

b. Disconnect connector (B), and measure the resistances between connectors (C) and (B1), and between
(B2) and (A) as shown in [Fig 18].
In this case, the measured resistance between connectors (C) and (B1) is higher than 1 MΩ and the
open circuit is between terminal 1 of connector (C) and terminal 1 of connector (B1).
 Fig 18: Measuring Resistance Between Connectors (C) And (B1)

Courtesy of KIA MOTORS AMERICA, INC.

3. Voltage Check Method

a. With each connector still connected, measure the voltage between the chassis ground and terminal 1 of
each of connectors (A), (B) and (C) as shown in [Fig 19].
The measured voltages of connectors are 5V, 5V and 0V respectively. So the open circuit is between
connectors (C) and (B).
 Fig 19: Measuring Voltage Between Chassis Ground And Terminal 1 Of Connectors

Courtesy of KIA MOTORS AMERICA, INC.

Short Circuit Test

1. Test Method for Short to Ground Circuit

1. Continuity Check with Chassis Ground
If short to ground circuit occurs as shown in [Fig 20], the broken point can be found by performing 2
(Continuity Check Method with Chassis Ground) as shown below.
 Fig 20: Checking Short Circuit

Courtesy of KIA MOTORS AMERICA, INC.

2. Continuity Check Method (with Chassis Ground)

NOTE: Lightly shake the wire harness vertically or horizontally

when measuring the resistance.

Specification (Resistance)
1Ω or less → Short to Ground Circuit
1MΩ or Higher → Normal Circuit

a. Disconnect connectors (A) and (C), and measure the resistance between connector (A) and Chassis
Ground as shown in [Fig 21].
If the measured resistances in lines 1 and 2 are "below 1 Ω" and "over 1 MΩ" respectively, line 1 has an
open circuit. (Line 2 is normal.) To find the exact broken point, check the sub line of line 1 as described in
the next step.
 Fig 21: Measuring Resistance Between Connector (A) And Chassis Ground

Courtesy of KIA MOTORS AMERICA, INC.

b. Disconnect connector (B), and measure the resistances between connector (A) and chassis ground, and
between (B1) and chassis ground as shown in [Fig 22].
The measured resistance between connector (B1) and chassis ground is 1Ω or less. The short to ground
circuit is between terminal 1 of connector (C) and terminal 1 of connector (B1).
 Fig 22: Measuring Resistance Between Connector (B1) And Chassis Ground

Courtesy of KIA MOTORS AMERICA, INC.

Voltage Drop Test

This test checks for voltage drop along a wire, or through a connection or a switch.

A. Connect the positive lead of a voltmeter to the end of the wire (or to the side of the connector or switch)
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 show the difference in voltage between the two points. A difference, or drop of more than
0.1 volts (50mV in 5V circuits), may indicate a problem. Check the circuit for loose or dirty connections.
Fig 23: Checking Voltage Drop Along Wire

Courtesy of KIA MOTORS AMERICA, INC.

Wire Harness Inspection Procedure

1. Before removing the wire harness, check the wire harness position and crimping in order to restore it
correctly.

2. Check for twisted, pulled or loose wire harness.

3. Check if the temperature of the wire harness is abnormally high.

4. Check for rotating, moving or vibrating wire harness against the sharp edge of a part.
5. Check the connection between the wire harness and any installed part.

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