Fuel System > Engine Control System

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

Item

Detecting Condition

Possible cause

DTC Strategy

•	PCM detects stop lamp input signal when vehicle stops.

•	Poor connection

•	Open or short to ground in signal circuit

•	Faulty PCM

Enable onditions

•	Engine running

•	Vehicle speed signal is normal.

•	Vehicle speed > 20kph (during 1sec or more)

Threshold value

•	Vehicle speed < 3kph

•	Vehicle acceleration< -6kph/s

•	Stop lamp "OFF" and not changing of stop lamp signal for more 3 sec.

Diagnosis Time

•	Continuous

MIL On Condition

•	2 driving cycles

Schematic Diagram

Monitor DTC Status

Check DTC Status

(1)	Connect scantool to Data Link Connector(DLC).

(2)

IG "ON".

(3)	Select "DTC" button, and then Press "DTC Status" to check DTC's information from the DTCs menu.

(4)	Read "DTC Status" parameter.

(5)

Is parameter displayed "Present fault"?

	▶ Go to "Terminal and connector inspection" procedure.
	▶ 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.

Has a problem been found?

	▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure
	▶ Go to " Power Circuit Inspection " procedure.

Power Circuit Inspection

■ Check voltage

IG "OFF".

2.	Disconnect the PCM connector.

3.	IG "ON" and ENG "OFF"

4.	Brake 'OFF' : Measure the voltage between brake lamp signal terminal of PCM harness connector and chassis ground.(Measurement "A")

Brake 'ON' : Measure the voltage between brake lamp signal terminal of PCM harness connector and chassis ground.(Measurement "B")

Specification :

Item	Brake 'OFF'	Brake 'ON'
Brake Lamp side	0V	Battery voltage

Is the measured voltage within specification ?

	▶ Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair as necessary and go to "Verification of Vehicle Repair" procedure.
	▶ Go to "Check open in harness" as follows.

■ Check open in harness

IG "OFF".

2.	Disconnect the brake switch and PCM connector.

Measure the resistance between brake lamp signal terminal of PCM harness connector and brake lamp signal terminal of Stop lamp switch harness connector.

Specification : Approx. below 1Ω

Is the measured resistance within specification ?

	▶ Go to "Check Battery voltage" as follows.
	▶ Repair open in harness and go to "Verification of Vehicle Repair" procedure.

■ Check battery voltage

1.	IG Key "OFF".

2.	Disconnect the stop lamp switch connector.

3.	Measure the voltage between power supply terminals of stop lamp switch harness connector and chassis ground.

4.	IG Key "ON".

Measure the voltage between power supply terminals of stop lamp switch harness connector and chassis ground.

Specification :

Item	IG "OFF"	IG "ON"
Power supply to brake switch side	Battery voltage	Battery voltage
Power supply to brake lamp side	0V	Battery voltage

Is the measured voltage within specification ?

	▶ 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.
	▶ 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 scantool and select "DTC" button.

2.	Press "DTC Status" button and confirm that "DTC Readiness Flag" indicates "Completed". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions

3.	Read "DTC Status" parameter

Is parameter displayed "History(Not Present) fault"?

	▶ System performing to specification at this time. Clear the DTC
	▶ Go to the applicable troubleshooting procedure.