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.
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., ECM sets P0571. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.
Item | Detecting Condition | Possible cause |
DTC Strategy |
•
ECM detects stop lamp input signal when vehicle stops. | 1. Poor connection 2. Open or short to ground in signal circuit 3. Faulty ECM |
Enable Conditions |
•
Engine works
•
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 |
•
NO MIL ON(DTC only) |
Fig.1) Normal data of Brake Switch during brake pedal released after depressed.
