How To Diagnose The Intermittent RPM Rising?

This trouble case occurs intermittently during driving, As a technician you have to give attention by road testing to probe the problem at the same time you got an idea where you begin to trouble shoot the problem.
Model: Hyundai Santa Fe (SM)
Year Model: 2002
Fuel: Gasoline
T/A : Auto
Displacement: 2000cc
N Code : Rough Idling
C Code: Poor Contact & Short Open Circuit
Subject: Intermittent RPM Rising – APS (Acceleration Position Sensor)
1) Condition:

1. Intermittently the engine RPM increases ( 750>1,300RPM) While Braking.

2) Cause:

1. APS (Acceleration Position Sensor) malfunction.

3) Diagnosis:

1. The APS signal is 899 mV at idle.
   
   Specification 0.6~0.75 Volt.
   
2. Check the Power  which is inputted to APS sensor, ground line,signal power – normal.
   Specification
   - Sensor power: 4.5~5.5 volt(Disconnect the connector)
   - Sensor ground: 0 volt
   - Sensor signal: idling 0.6~.75 volt, Full throttle 3.6~4.6 volt
   
3. Inspect the terminal of APS connector – Normal.
   
4. Supply power source (0.6v) to APS signal line using simulation mode in GDS
   = Normal operation of engine.
   = Replace the APS.
   = After replacing the APS, the sensor data and all system operate normally.

4) Repair Guide

• Replace the Acceleration Position Sensor.

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