ETC(Electronic Throttle Control Valve) is the device controlling amount of air to engine acccording to driver's intension. Different from the existing mechanical throttle valve which is composed of accelerator pecal and connecting wire cable, ETC consists of a motor, a throttle body and a throttle position sensor. Receiving input signals from electronic accelerator pedal module, PCM lets ETC motor control throttle valve. With ETC, cruise control system works without any additional device.
Checking output signals from TPS1 every 8.5 sec. under detecting condition, if an output signal is above 4.75V for more than 0.1 sec., PCM sets P0123. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.
Item | Detecting Condition | Possible Cause | ||||||
DTC Strategy | ● signal high | ● Poor connection ● Open or short to battery in signal harness ● Open in ground harness ● TPS ● PCM | ||||||
Enable condition | ● IG "ON | |||||||
threshold value | ● The voltage of TPS 〉4.75V | |||||||
diagnosis time | ● Continuous (more than 0.1 sec. failure for every 8.5 sec.test) | |||||||
MIL ON condition | ● 2 driving cycles | |||||||
Throttle opening ( ° ) | Output voltage(V) [Vref=5.0] | |
TPS1 | TPS2 | |
0° | 0.0V | 5.0V |
10° | 0.5V | 4.5V |
20° | 0.9V | 4.1V |
30° | 1.4V | 3.6V |
40° | 1.8V | 3.2V |
50° | 2.3V | 2.7V |
60° | 2.7V | 2.3V |
70° | 3.2V | 1.8V |
80° | 3.6V | 1.4V |
90° | 4.1V | 0.9V |
100° | 4.5V | 0.5V |
110° | 5.0V | 0.0V |
IG "OFF" ＆ connect scantool.
ENG "ON" and warm -up the engine to normal operating temperature.
Monitor "TPS1" item on the service data.
Procedure of ETS Initialization
Erase the trouble codes on PCM
Turn the ignition key off and keep this condition until the main relay is turned off.(It will takes 10 second)
Turn ignition key on more than 1second to record the throttle motor position on the EEPROM
Is the service data displayed correctly ?
▶ Fault is intermittent caused by poor contact in the sensor’s and/or PCM’s connector or was repaired and PCM memory was not cleared. Thoroughly check connectors for looseness, poor connection, ending, corrosion, contamination, deterioration, or damage. Repair or replace as 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 "Signal Circuit Inspection" procedure.
Check voltgae
IG "OFF" and disconnect TPS connector.
IG "ON" and ENG "OFF"
Measure voltage between terminal 7 of TPS harness connector and chassis ground.
Specification : Approx. 5V
Is the measured voltage within specification?
▶ Go to "Check short to battery in harness" as follows.
▶ Go to "Check open in harness" as follows.
Check open in harness
IG "OFF" and disconnect TPS connector and PCM connector.
Measure resistance between terminal 7 of TPS harness connector and terminal 48 of PCM harness connector.
Specification : Below 1Ω
Is the measured resistance within specification?
▶ Go to "Ground Circuit Inspection" procedure.
▶ Repair open in harness, and go to "Verification of Vehicle Repair" procedure.
Check short to battery in harness
IG "OFF" and disconnect TPS connector and PCM connector.
Measure resistance between terminals 4 and 7 of TPS harness connector.
Measure resistance between terminals 1 and 7 of TPS harness connector.
Measure resistance between terminals 2 and 7 of TPS harness connector.
Measure resistance between terminals 3 and 7 of TPS harness connector.
Specification : Infinite
Is the measured resistance within specification?
▶ Go to "Ground circuit inspection " procedure.
▶ Repair short to battery in harness, and go to "Verification of Vehicle Repair" procedure.
IG "OFF" and disconnect TPS connector.
IG "ON" and ENG "OFF"
Measure voltage between terminal 4 of TPS harness connector and chassis ground.
Measure voltage between terminals 4 and 8 of TPS harness connector.
Specification : Voltage difference between measurement "A" and "B" is below 200mV.
Is the measured voltage within specification?
▶ Go to "Component inspection" procedure.
▶ Repair open or contact resistance in harness, and go to "Verification of Vehicle Repair" procedure.
Check TPS
IG "OFF" and disconnect TPS connector.
Measure resistance between terminals 4 and 5 of TPS connector.(component side)
Specificaton : 4 ~ 6kΩ
Is the measured resistance within specification?
▶ Substitute with a known - good PCM and check for proper operation. If the problem is corrected, replace PCM and go to "Verification of Vehicle Repair" procedure.
▶ Substitute with a known - good ECT motor ＆ TPS and check for proper operation. If the problem is corrected, replace ECT motor ＆ TPS and go to "Verification of Vehicle Repair" procedure.
Procedure of ETS Initialization
Erase the trouble codes on PCM
Turn the ignition key off and keep this condition until the main relay is turned off.(It will takes 10sec.)
Turn ignition key on more than 1second to record the throttle motor position on the EEPROM
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.
