Component Location
General Description
Brake switch monitors malfunction of accel pedal sensor(APS).
Drivers depress brake pedal when 1).the voltage higher than driver's intension is detected due to APS malfunction(signal circuit short to high voltage) 2).engine power generates excessively due to fault signal.
Like previous example, if driver's intension to decelerate is transmitted to ECM(brake pedal depressed) when APS signal is high, ECM consider APS to be fault and Limp Home mode is activated.
When Limp Home mode is activated, engine speed is fixed at 1200RPM and driving performance is limited, later, if correct APS signal is detected, Limp Home mode is deactivated immediately.
DTC Description
P2299 is set when brake signal is inputted to ECM for more than 0.5 sec. while APS is depressed more than 5% at above 870RPM, 2Km/h. And Limp Home mode is activated with the DTC code occurence. Later, if correct APS signal is detected, Limp Home mode is deactivated immediately. This code is set when APS signal is a bit higher than the voltage at accelerator released position and driver's pedal manipulation, therfore careful inspection of APS and checking driver's pedal depressing habit is required.
DTC Detecting Condition
Item | Detecting Condition | Possible Cause |
DTC Strategy | Voltage Monitoring
| APS 1 Circuit
APS 2 Circuit
APS component
|
Enable Conditions | Engine run ( engine speed below 880RPM, vehicle speed below 2Km/h)
|
Threshold Value | Brake pedal singal inputted at APS output voltage above 5% (Enabled when brake pedal released or accelerator pedal depressed 200% per sec.)
|
Diagnostic Time | 3000ms
|
Fail Safe | Fuel Cut | NO | APS standard value is 0%.
Limp home idle is fixed at (1200RPM)
|
EGR Off | NO |
Fuel Limit | YES |
MIL | NO |
Specification
| Pedal released | Pedal depressed | Sensor Type |
APS 1 | 0.7V~0.8V | 3.8V~4.4V | Variable resistance type (Potentiometer) |
APS 2 | 0.275V~0.475V | 1.75V~2.35V |
Diagnostic Circuit Diagram
Signal Waveform
Fig.1) APS 1 and APS 2 signals are measured simultaneously, Check if output value is rising and APS 2 is 1/2 of APS 1 signal.
noteAPS 2 Ground checking signal is for ECM to monitor APS 2. This signal drops APS 2 output voltage to below 200.39mV per 200msec. If APS 2 output voltage does not drop to below 200.39mV, ECM sets DTC as recognizing ground circuit error of APS 2 .
? The waveform below 200.39mV is not detectable in Ground checking signal waveform of APS 2 signal. Instead, the waveform which drops a little is detected. If APS 2 data of "SERVICE DATA" on the Scantool varies from 350mV to 0mV periodically, it means it works well.