Kia Optima Hybrid: Cruise Control System / Troubleshooting

Kia Optima Hybrid (TF HEV) 2016-2020 Service Manual / Engine Electrical System / Cruise Control System / Troubleshooting

Trouble Symptom Charts

Trouble Symptom 1

Trouble Symptom 2

Trouble symptom	Probable cause	Remedy
The set vehicle speed varies greatly upward or downward "Surging" (repeated alternating acceleration and deceleration) occurs after setting	Malfunction of the vehicle speed sensor circuit	Repair the vehicle speed sensor system, or replace the part
	Malfunction of brake system	Check input and output signals at brake system

Trouble Symptom 3

Trouble symptom	Probable cause	Remedy
The CC system is not canceled when the brake pedal is depressed	Damaged or disconnected wiring of the brake pedal switch or malfunction of the brake stroke sensor or circuit	Repair the harness or replace the brake pedal switch
	Malfunction of the brake signals or brake system	Check input and output signals at HCU or brake system

Trouble Symptom 4

Trouble symptom	Probable cause	Remedy
The CC system is not canceled when the shift lever is moved to the "N" position (It is canceled, however, when the brake pedal is depressed)	Damaged or disconnected wiring of inhibitor switch input circuit	Repair the harness or repair or replace the inhibitor switch
	Improper adjustment of inhibitor switch
	Malfunction of the TCU signals	Check input and output signals at TCU

Trouble Symptom 5

Trouble symptom	Probable cause	Remedy
Cannot decelerate (coast) by using the "SET/–" switch	Temporary damaged or disconnected wiring of "SET/–" switch input circuit	Repair the harness or replace the "SET/–" switch
Cannot decelerate (coast) by using the "SET/–" switch	Malfunction of the cluster signals	Check input and output signals at cluster

Trouble Symptom 6

Trouble symptom	Probable cause	Remedy
Cannot accelerate or resume speed by using the "RES/+" switch	Damaged or disconnected wiring, or short circuit, or "RES/+" switch input circuit	Repair the harness or replace the "RES/+" switch
	Malfunction of the cluster signals	Check input and output signals at cluster

Trouble Symptom 7

Trouble symptom	Probable cause	Remedy
CC system can be set while driving at a vehicle speed of less than 40km/h (25mph), or there is no automatic cancellation at that speed	Malfunction of the vehicle-speed sensor circuit	Repair the vehicle speed sensor system, or replace the part
	Malfunction of the brake system	Check input and output signals at brake system

Trouble Symptom 8

Trouble symptom	Probable cause	Remedy
The cruise main switch indicator lamp does not illuminate (But CC system is normal)	Damaged or disconnected bulb of cruise main switch indicator lamp	Repair the harness or replace the part.
	Harness damaged or disconnected	Repair the harness or replace the part.

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 Switch Schematic Diagrams

Circuit Diagram ...

Other information:

Kia Optima Hybrid (TF HEV) 2016-2020 Service Manual: Components and Components Location

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Kia Optima Hybrid (TF HEV) 2016-2020 Service Manual: Relay Box (Engine Compartment) Components and Components Location

Components ...