Hyundai Elantra: Engine Control System / Accelerator Position Sensor (APS)
Description and operation
Accelerator Position Sensor (APS) is installed on the accelerator pedal module and detects the rotation angle of the accelerator pedal. The APS is one of the most important sensors in engine control system, so it consists of the two sensors which adapt individual sensor power and ground line. The second sensor monitors the first sensor and its output voltage is half of the first one. If the ratio of the sensor 1 and 2 is out of the range (approximately 1/2), the diagnostic system judges that it is abnormal.

Specifications
Accelerator Position
|
Output Voltage [V]
|
APS1
|
APS2
|
C.T
| 0.7 - 0.8
| 0.33 - 0.43
|
W.O.T
| 3.98 - 4.22
| 1.93 - 2.17
|
Schematic diagrams

Harness Connector

Repair procedures
1. | Connect the diagnostic tool on the Data Link Connector (DLC). |
2. | Switch "ON" the ignition. |
3. | Measure the output voltage of the APS 3 and 6 at C.T and W.O.T. Specification : Refer to "Specification" |
|
1. | Turn ignition switch OFF and disconnect the battery negative (-) terminal. |
2. | Disconnect the accelerator position sensor connector (A). 
|
3. | Remove the accelerator pedal module after loosening the nut (A). 
|
1. | Install in the reverse order of removal. |
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InspectionCheck it by the procedure below to see if the function of the ECM is normal.1.Turn the ignition key to the "ON" position.2.Cover the forward facing sensor.3.Head a light to the rearward looking sensor.4.The ECM should be darkened as soon as the rearward looking sensor detects the light.
•
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