3.
Monitor "APS1 ＆ APS2" parameters on the scantool.
Pedal Position | Output Voltage(V) [Vref = 5.0V] | |
APS1 | APS2 | |
C.T | 0.7 ~ 0.8V | 0.275 ~ 0.475V |
W.O.T | 3.8 ~ 4.4V | 1.75 ~ 2.35V |
APS(Acceleration Position Sensor) measures driver's accelerating intension using a potentiometer and APS signal is transmitted to the PCM. The pedal's position is converted as voltages of potentiometer in the APS.The absence of a mechanical link between the accelerator pedal and throttle valve presents a risk of loss of control of the engine in the event of a failure of the component. Therefore, APS has the two potentiometers whose slides are mechanically solid. APS 2 decides whether or not APS 1 ＆ 2 is faulty.
Checking output signals from APS 1 and 2, under detecting condition, if output signals difference between APS 1 and 2 are detected more than 4.5% for the specified number of times., PCM sets P2138. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till 1 driving cycle.
Item | Detecting Condition | Possible Cause | ||||||
DTC Strategy | ● This code detects a correlation error between APS 1 and APS 2 | ● Poor connection ● Open or short in APS Circuit ● Faulty APS ● Faulty PCM | ||||||
Enable condition | ● Ignition "ON" | |||||||
threshold value | ● Difference between APS1 and APS2 Normalized values 〉 4.5% | |||||||
diagnosis time | ● Contineous (More than 0.32sec. Failure for every 9.36sec. Test) | |||||||
MIL ON condition | ● 1 Driving Cycle | |||||||
Pedal Position | Output Voltage(V) [Vref = 5.0V] | |
APS1 | APS2 | |
C.T | 0.7 ~ 0.8V | 0.275 ~ 0.475V |
W.O.T | 3.8 ~ 4.4V | 1.75 ~ 2.35V |
Connect scantool to DLC.(Data Link Connector)
Warm up the engine to normal operating temperature.
Monitor "APS1 ＆ APS2" parameters on the scantool.
Pedal Position | Output Voltage(V) [Vref = 5.0V] | |
APS1 | APS2 | |
C.T | 0.7 ~ 0.8V | 0.275 ~ 0.475V |
W.O.T | 3.8 ~ 4.4V | 1.75 ~ 2.35V |
Are those "APS1 ＆ APS2" parameters displayed correctly ?
▶Fault is intermittent caused by poor contact in Sensor’s and/or PCM’s connector or was repairedand PCM memory was not cleared. Thoroughly check connectors for looseness, poorconnection, bending, corrosion, contamination, deterioration, or damage. Repair or replaceas necessary and go to "Verification of Vehicle Repair" procedure
▶Go to "Terminal and connector inspection" procedure.
Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
Has a problem been found?
▶Repair as necessary and go to "Verification of Vehicle Repair" procedure
▶Go to " Power Circuit Inspection " procedure.
IG "OFF"
Disconnect APS connector.
IG "ON" ＆ ENG "OFF".
Measure voltage between terminal 1 of APS harness connector and chassis ground.
Measure voltage between terminal 4 of APS harnesss connector and chassis ground.
Specification : Approx. 5V
Is the measured voltage within specification ?
▶ Go to "Signal Circuit Inspection" procedure.
▶ Repair or replace as necessary and then, go to "Signal Circuit Inspection" procedure.
IG "OFF".
Disconnect APS and PCM connector.
Measure resistance between terminal 2 and 3 of APS harness connector.
Specification : Infinite
Is the measured resistance within specification ?
▶ Go to "Component Inspection" procedure.
▶ Repair or replace as necessary and then, go to "Verification of Vehicle Repair" procedure.
Check APS
IG "ON" ＆ ENG "OFF".
Measure signal waveform of APS 1 and APS 2 by stepping on and off with scantool
Pedal Position | Output Voltage(V) [Vref = 5.0V] | |
APS1 | APS2 | |
C.T | 0.7 ~ 0.8V | 0.275 ~ 0.475V |
W.O.T | 3.8 ~ 4.4V | 1.75 ~ 2.35V |
Is the measured signal waveform O.K ?
▶ Substitute with a known-good PCM and check for proper operation. If the problem is corrected,replace PCM and then go to "Verification of Vehicle Repair" procedure.
There is a memory reset function on scantool that can erase optional parts automaticallydetected and memorized by PCM.
Before or after testing PCM on the vehicle, use this function to reuse the PCM on the others
▶ Substitute with a known-good APS and check for proper operation. If the problem is corrected,replace APS and then go to "Verification of Vehicle Repair" procedure.
After a repair, it is essential to verify that the fault has been corrected.
Monitor and record the Freeze Frame Data for the Diagnostic Trouble Code(DTC) which has been diagnosed.
Using a Scantool, Clear the DTCs
Operate the vehicle within conditions noted in the freeze frame data or enable conditions
Monitor that all rediness test have been verified as " Complete "
Are any DTCs present ?
▶ Go to the applicable troubleshoooting procedure.
▶ System is performing to specification at this time.
