Hyundai Sonata LF: Brake System / Stop Lamp Switch Repair procedures

Hyundai Sonata LF 2014-2019 Service Manual / Brake System / Brake System / Stop Lamp Switch Repair procedures

Adjustment
1.
Turn ignition switch OFF and disconnect the negative (-) battery cable.
2.
Remove the lower crash pad.
(Refer to Body - "Crash Pad")
3.
Remove the knee airbag.
(Refer to Rstraint - "Air Bag Module")
4.
Confirm the gap between stop lamp switch and bracket.

Stop lamp clearance : 1.0 ~ 2.0 mm (0.04~ 0.08 in.)

5.
If the gap between stop lamp switch and bracket is not 1.0~2.0mm(0.04~0.08in), check the mounting clip and other part of around stop lamp.
6.
If there is normal, remove the stop lamp switch and then install again.
Inspection
1. Fuse inspection
Mount the test fuse to the switch fuse and relay fuse part to confirm a normal joint fit.

2. GDS Data Analysis
1.
Analyze GDS data and confirm if there is anything wrong with the stop lamp switch.
(1)
Connect the GDS to the self-diagnosis connector.
(2)
Turn the spark switch on
(3)
Step on the brake pedal.
(4)
Inspect the "brake switch" category that displays the "sensor data" GDS.)

Normal waveform : The pressure sensor signal value will change according to the brake ON/OFF switch.

3. Inspection of connector by each part
Check to see whether or not each connector has been damaged, or terminal surge, or incomplete connection has taken place
[Engine room junction box]

[Stop signal electronic module]

[ABS/VDC control module]

4. Inspect the stop lamp circuit
Connect probe to each terminal wire and confirm oscilloscope waveform.
[Stop lamp switch input/output]

[Stop signal electronic module input/output]

[Oscilloscope waveform screen]

Removal
1.
Turn ignition switch OFF and disconnect the negative (-) battery cable.
2.
Remove the lower crash pad.
(Refer to Body - "Crash Pad")
3.
Remove the knee airbag.
(Refer to Rstraint - "Air Bag Module")
4.
Disconnect the stop lamp switch connector (A).

5.
Pull the locking plate (A) as indicated by the arrow.

6.
Turn stop lamp switch 45° counterclockwise and remove it.

7.
Inspect a removed stop lamp switch along the below procedures.
(1)
Confirm a normal connection with terminal part
A.
A confirmation can be made to see if the connector has been secured properly and if a connection mark is present.

(2)
Perform the inspection of parts resistance

Resistance (?)
3-4
1-2
Non rod protruded
(switch turned OFF)
Infinite
0
Rod protruded
(switch turned On)
0
Infinite

Installation
1.
Fix the brake pedal arm and insert fully the stop lamp switch as hiding contact part.

2.
After inserting, turn the stop switch (A) 45° clockwise, and then assemble locking plate (B) by pushing.

3.
Confirm the gap between stop lamp switch and bracket.

Stop lamp clearance : 1.0 ~ 2.0 mm (0.04~ 0.08 in.)

   
If the gap between stop lamp switch and bracket is not 1.0~2.0mm(0.04~0.08in), perform the above process again.
4.
Connect the stop lamp switch connector.
5.
Install the knee air bag.
(Refer to Restraint - "Knee Airbag (KAB) Module")
6.
Install the lower crash pad.
(Refer to Body - "Crash Pad")

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    Troubleshooting 1. Part diagnosis Items Cause Symptom Switch fuse Faulty fuse connection, Damaged fuse - DTC Code : P0504 - Symptom : Shifting gear trouble, Starting failure, Cruise control function cancelation trouble, EPB function cancelation trouble, Stop lamp lighting trouble, ESP OFF light illuminated...

    Stop Signal Electronic Module Components and Components Location

    C..

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