Hyundai Sonata LF: Seat Electrical / Seat Heater Switch Repair procedures

Hyundai Sonata LF 2014-2019 Service Manual / Body Electrical System / Seat Electrical / Seat Heater Switch Repair procedures

Removal

[Front Seat]

1.	Disconnect the negative (-) battery terminal.

2.	Remove the heater and A/C control unit. (Refer to Heating, Ventilation and Air Conditioning - "Controller")

[Rear Seat]

1.	Disconnect the negative (-) battery terminal.

2.	Remove the rear door window switch. (Refer to Power Windows - "Power Window Switch")

Seat Heater Switch Schematic Diagrams

C..

Air Ventilation Seat Components and Components Location

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Other information:

Hyundai Sonata LF 2014-2019 Service Manual: Troubleshooting

Trouble Symptom Charts Trouble Symptom 1 Trouble Symptom 2 Trouble symptomProbable causeRemedyThe set vehicle speed varies greatly upward or downward"Surging" (repeated alternating acceleration and deceleration) occurs after settingMalfunction of the vehicle speed sensor circuitRepair the vehicle speed sensor system, or replace the partMalfunction of ECMCheck input and output signals at ECM Trouble Symptom 3 Trouble symptomProbable causeRemedyThe CC system is not canceled when the brake pedal is depressedDamaged or disconnected wiring of the brake pedal switchRepair the harness or replace the brake pedal switchMalfunction of the ECM signalsCheck input and output signals at ECM Trouble Symptom 4 Trouble symptomProbable causeRemedyThe 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 circuitRepair the harness or repair or replace the inhibitor switchImproper adjustment of inhibitor switchMalfunction of the ECM signalsCheck input and output signals at ECM Trouble Symptom 5 Trouble symptomProbable causeRemedyCannot decelerate (coast) by using the "SET/–" switchTemporary damaged or disconnected wiring of "SET/–" switch input circuitRepair the harness or replace the "SET/–" switchMalfunction of the ECM signalsCheck input and output signals at ECM Trouble Symptom 6 Trouble symptomProbable causeRemedyCannot accelerate or resume speed by using the "RES/+" switchDamaged or disconnected wiring, or short circuit, or "RES/+" switch input circuitRepair the harness or replace the "RES/+" switchMalfunction of the ECM signalsCheck input and output signals at ECM Trouble Symptom 7 Trouble symptomProbable causeRemedyCC system can be set while driving at a vehicle speed of less than 40km/h (25mph), or there is no automatic cancellation at that speedMalfunction of the vehicle-speed sensor circuitRepair the vehicle speed sensor system, or replace the partMalfunction of the ECM signalsCheck input and output signals at ECM Trouble Symptom 8 Trouble symptomProbable causeRemedyThe cruise main switch indicator lamp does not illuminate (But CC system is normal)Damaged or disconnected bulb of cruise main switch indicator lampRepair the harness or replace the part...

Hyundai Sonata LF 2014-2019 Service Manual: Roof Trim