Component Location
General Description
Driver’s intension to accelerate is transmitted to ECM through Accelerator Pedal Sensor(APS) . And APS, whose mechanism is same as TPS, is required for ECM to determine optimum fuel injection quantity.
As fidelity of APS is strongly required, APS is devided into two. One is APS1, which outputs main signals and the other is APS2, which monitors APS1 performance.
APS1 and 2 do not share power supply and ground. Normally, APS2 output voltage is the half of APS1 and if the ratio of two signal is out of specified value, error is recognized then, Limp Home mode is activated.
When Limp Home mode is activated, engine speed is fixed at 1000RPM and driving performance is limited to prevent excessive power generation due to APS false signal.
DTC Description
P2138 is set when APS1 and 2 signal voltage is different from correct value by more than 8%. This code is due to APS circuit or component failure.
DTC Detecting Condition
Item | Detecting Condition | Possible Cause |
Threshold Value | ? The difference between APS 1 and APS 2 is out of specified value by more than 8% | ? APS 1 circuit ? APS 2 circuit ? APS component |
Fail Safe | ? Idle RPM rises to 1000RPM ? Engine power generation drops to 75% regardless of RPM | Check Lamp |
YES |
? OC (Open Circuit) : Open, SC- (Short Circuit - ) : Short to ground , SC+ (Short Circuit +) : Short to battery
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 |
Schematic Diagram
Signal Waveform