P0571

P0571

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
Checking input signals from stop lamp switch under detecting condition, if the operation state of stop lamp switch does not change for more than 3 sec., PCM sets P0571. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.

DTC Detecting Condition:

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 F5(INFO) to check DTC's information from the DTCs menu
4. Read "DTC Status" parameter.






5. Is parameter displayed "Present fault"?

YES
a. Go to "Terminal and Connector inspection" procedure.

NO
a. 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 terminal condition. 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 Supply Circuit Inspection
1. Check voltage
1. IG "OFF".
2. Disconnect the PCM connector.
3. IG "ON" and ENG "OFF"
4. Brake "OFF" : Measure the voltage between terminal 23 of PCM harness connector and chassis ground.
5. Brake "ON" : Measure the voltage between terminal 23 of PCM harness connector and chassis ground.

Specification :









6. 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 "OFF".
2. Disconnect the stop lamp switch and PCM connector.
3. Measure the resistance between terminal 23 of PCM harness connector and terminal 1 of stop lamp switch harness connector.

Specification : Approx below 1 ohm






4. Is the measured resistance within specification ?

YES - Go to "Check voltage" as follows.

NO - Repair open in circuit and go to "Verification of Vehicle Repair" procedure.

3. Check voltage
1. IG "OFF".
2. Disconnect the stop lamp switch connector.
3. Measure the voltage between stop lamp switch terminal 2,4 and chassis ground.
4. IG "ON" and ENG "OFF"
5. Measure the voltage between stop lamp switch terminal 2,4 and chassis ground.

Specification :









6. Is the measured voltage within specification ?

YES
- Substitute with a known - good stop lamp switch and check for proper operation.
If the problem is corrected, replace stop lamp switch and go to "Verification of Vehicle Repair" procedure.

NO
- Check the fuse between battery and stop lamp switch.
- Repair open or short in power harness of stop lamp 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. Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode
2. Press F5(INFO) 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.