P0504

COMPONENT LOCATION





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

ECM sets DTC P0504 if the ECM detects signal of the brake warning lamp and brake switch are not correlate within the predetermined time.

DTC DETECTING CONDITION





SIGNAL WAVEFORM AND DATA










SPECIFICATION





SCHEMATIC DIAGRAM





MONITOR DTC STATUS

1. Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode.
2. Press F4(DTAL) to select DTC information from the DTCs menu.
3. Confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions.
4. Read "DTC Status" parameter.
5. Is parameter displayed "History(Not Present) fault"?

NOTE:
- History (Not Present) fault : DTC occurred but has been cleared.
- Present fault : DTC is occurring at present time.

YES
> Fault is intermittent caused by poor contact in the sensor's and/or ECM's connector or was repaired and ECM memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.
NO
> Go to next step as below.

TERMINAL AND CONNECTOR INSPECTION

1. Many malfunctions in the electrical system are caused by poor harness(es) 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
> Check for poor connection between ECM and component: backed out terminal, improper mating, broken locks or poor terminal to wire connection. Repair as necessary and go to "Verification of Vehicle Repair" procedure

COMPONENT INSPECTION

1. Ignition "OFF"
2. Disconnect stop lamp switch harness connector.
3. Check stop lamp switch for continuity between each terminal(Stop lamp side). Refer to below table.
Specification :









4. Is resistance within the specification?
YES
> Go to next step as below
NO
> Substitute with a known-good stop lamp SW and check for proper operation. If the problem is corrected, replace stop lamp SW and then go to "Verification of Vehicle Repair" procedure.

CHECK BRAKE TEST SWITCH
1. Reconnect stop lamp connector.
2. Disconnect ECM harness connector.
3. Ignition "ON" & Engine "OFF"
4. Measure voltage between terminal 74 of the ECM harness connector and chassis ground
Specification :









5. Is voltage within the specification?
YES
> Go to next step as below
NO
> Check for open or short in signal circuit. Repair as necessary and go to "Verification of Vehicle Repair" procedure

CHECK BRAKE LIGHT SWITCH
1. Measure voltage between terminal 83 of the ECM harness connector and chassis ground









2. Is voltage within the specification?
YES
> Go to next step as below
NO
> Check for open or short in signal circuit. Repair as necessary 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. Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode.
2. Press F4(DTAL) and confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions.
3. Read "DTC Status" parameter.
4. Is parameter displayed "History(Not Present) fault"?
YES
> System performing to specification at this time. Clear the DTC
NO
> Go to the applicable troubleshooting procedure.