Kia Optima Hybrid Owner's Manual Quiz
Engine Electrical System

Troubleshooting

In this manual: Engine Electrical System
General Information — 4Engine Mechanical System — 50Engine Electrical System — 20Emission Control System — 30Engine Control System/Fuel System — 84Automatic Transmission — 98Drive Shaft and Axle — 15Suspension System — 36Steering — 12Restraints — 50Brake System — 38Body (Interior and Exterior) — 54Body Electrical System — 233Heating, Ventilation, and Air Conditioning — 57
~2min read

Symptom Troubleshooting Tables

Symptom Troubleshooting 1

Symptom 2
Symptom of Malfunction Probable Cause Remedy
Vehicle set speed fluctuates greatly up or down
"Hunting" (repeated alternating acceleration and deceleration) occurs after setting		 Vehicle speed sensor circuit malfunction Repair the vehicle speed sensor system or replace the component.
Brake System Malfunction Check the input and output signals of the brake system.

Symptom 3
Symptom of Malfunction Probable Cause Remedy
CC system does not cancel when the brake pedal is depressed Brake pedal switch wiring is damaged or disconnected, or the brake travel sensor or circuit is malfunctioning Repair the harness or replace the brake pedal switch.
Brake signal or brake system malfunction Check the input and output signals of the HCU or brake system.

Symptom 4
Symptom of Malfunction Probable Cause Remedy
The CC system is not cancelled when the shift lever is moved to the "N" position (however, it is cancelled when the brake pedal is pressed). Inhibitor switch input circuit wiring is damaged or disconnected. Repair the harness or repair or replace the inhibitor switch.
Incorrect inhibitor switch adjustment
TCU Signal Malfunction Check the input and output signals at the TCU.

Symptom 5
Symptom of Malfunction Probable Cause Remedy
Cannot decelerate (coast) using the "SET/–" switch. Temporary damage or disconnection of the SET/– switch input circuit wiring Repair the harness or replace the "SET/–" switch.
Cluster Signal Malfunction Inspect the input and output signals at the cluster

Symptom 6
Symptom of Malfunction Probable Cause Remedy
Cannot accelerate or resume speed using the "RES/+" switch. Damaged or disconnected wiring, or a short circuit, or the input circuit of the "RES/+" switch Repair the harness or replace the "RES/+" switch.
Cluster Signal Malfunction Inspect the input and output signals at the cluster

Symptom 7
Symptom of Malfunction Probable Cause Remedy
The CC system can be set while driving at a speed below 40 km/h, or there is no automatic cancellation at this speed. Vehicle speed sensor circuit malfunction Repair the vehicle speed sensor system or replace the component.
Brake System Malfunction Check the input and output signals of the brake system.

Symptom 8
Symptom of Malfunction Probable Cause Remedy
Cruise control main switch indicator lamp does not illuminate (but the CC system operates normally) Damaged or disconnected cruise control main switch indicator lamp bulb Repair the harness or replace the component.
Harness is damaged or disconnected

Test yourself

A quick Kia Optima Hybrid Owner's Manual quiz: every answer comes with an explanation and a link to the manual page.