P0504

GENERAL DESCRIPTION

The Stop lamp switch is used to judge whether the acceleration system is abnormal or not. The stop lamp switch has a duplex system(signals brake test or brake light) to memorize the abnormality when the signals of depressing and releasing the brake pedal are detected simultaneously.

DTC DESCRIPTION

Checking output signals from both brake switch. when all of them are On or OFF simultaneously, if abnormal signal is detected for more than 0.5 sec., an error is recognized. And if this condition lasts for certain period, PCM sets P0504. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till cosecutive 2 driving cycle.

DTC DETECTING CONDITION





SPECIFICATION





SCHEMATIC DIAGRAM





MONITOR DTC STATUS

1. Check DTC Status
(1) Connect scantool to Data Link Connector(DLC).
(2) IG "ON".
(3) Select "Diagnostic Trouble Codes(DTCs)" mode, and then Press F4(DTAL) to check DTC's information from the DTCs menu
(4) Read "DTC Status" parameter.




(5) Is parameter displayed "Present fault"?
YES
> Go to "Terminal and connector inspection" procedure.
NO
> Fault is intermittent caused by poor contact in the sensor's and/or PCM's connector or was repaired and PCM memory was not cleared. Thoroughly check connectors for looseness, poor connection, ending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.

TERMINAL AND CONNECTOR INSPECTION

1. Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?
YES
> Repair as necessary and go to "Verification of Vehicle Repair" procedure
NO
> Go to " Power Circuit Inspection " procedure.

POWER CIRCUIT INSPECTION

1. Check voltage
(1) IG Key "OFF".
(2) Disconnect the PCM connector.
(3) IG Key "ON" and keep the brake taking off.
(4) Measure the voltage between terminal C201-1 (21) of PCM connector and chassis ground.
(5) Measure the voltage between terminal C201-1 (23) of PCM connector and chassis ground.
(6) Keep the brake stepping on.
(7) Measure the voltage between terminal C201-1 (21) of PCM connector and chassis ground.
(8) Measure the voltage between terminal C201-1 (23) of PCM connector and chassis ground.
Specification :









(9) Is the measured voltage within specification ?
YES
> Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO
> Go to "Check open in harness" as follows.
2. Check open in harness
(1) IG Key "OFF".
(2) Disconnect the brake switch and PCM connector.
(3) Measure the resistance between terminal C201-1(21) of PCM harness connector and terminal 4 of Brake switch harness side.
(4) Measure the resistance between terminal C201-1(23) of PCM harness connector and terminal 2 of Brake switch harness side.

Specification : Approx. below 1Ohms





(5) Is the measured resistance within specification ?
YES
> Go to "Check voltagen" procedure.
NO
> Repair open in circuit and go to "Verification of Vehicle Repair" procedure.
3. Check voltage
(1) IG Key "OFF".
(2) Disconnect the brake switch connector.
(3) Measure the voltage between brake lamp switch terminal and chassis ground.
(4) Measure the voltage between brake switch terminal and chassis ground.
(5) IG Key "ON".
(6) Measure the voltage between brake lamp switch terminal and chassis ground.
(7) Measure the voltage between brake switch terminal and chassis ground.
Specification :





(8) Is the measured voltage within specification ?
YES
> Substitute with a known - good brake switch and check for proper operation. If the problem is corrected, replace brake switch and go to "Verification of Vehicle Repair" procedure.
NO
> Check the fuse between battery and brake switch.
> Repair open or short in power circuit of brake switch and go to "Verification of Vehicle Repair" procedure.

VERIFICATION OF VEHICLE REPAIR

After a repair, it is essential to verify that the fault has been corrected.
1. Monitor and record the Freeze Frame Data for the Diagnostic Trouble Code(DTC) which has been diagnosed.
2. Using a Scantool, Clear the DTCs
3. Operate the vehicle within conditions noted in the freeze frame data or enable conditions
4. Monitor that all rediness test have been verified as " Complete "
5. Are any DTCs present ?
YES
> Go to the applicable troubleshoooting procedure.
NO
> System is performing to specification at this time.