P0123

DTC P0123






GENERAL DESCRIPTION
ETC (Electronic Throttle Control Valve) is the device controlling amount of air to engine according to driver's intension. Different from the existing mechanical throttle valve which is composed of accelerator pedal 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.

DTC DESCRIPTION
Checking output signals from TPS1 every 8.5 sec. under detecting condition, if an output signal is above 4.75 V for more than 0.1 sec., PCM sets P0123. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.

DTC Detecting Condition:

DTC DETECTING CONDITION

Specification:

SPECIFICATION

Schematic Diagram:

SCHEMATIC DIAGRAM

Signal Waveform And Data:

SIGNAL WAVEFORM AND DATA

MONITOR SCANTOOL DATA
1. IG "OFF"& connect Scantool.
2. ENG "ON" and warm -up the engine to normal operating temperature.




3. Monitor "TPS1" item on the service data.

CAUTION: 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 seconds)
- Turn ignition key on more than 1 second to record the throttle motor position on the EEPROM

4. Is the service data displayed correctly?

YES - 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

NO - Go to "Terminal and connector inspection" procedure

TERMINAL AND CONNECTOR INSPECTION
1. 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.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination,deterioration, or damage.
3. Has a problem been found?

YES - Repair as necessary and go to "Verification of Vehicle Repair" procedure

NO - Go to "Signal Circuit Inspection" procedure.

SIGNAL CIRCUIT INSPECTION
1. Check voltage
a. IG "OFF" and disconnect TPS connector.
b. IG "ON" and ENG "OFF"




c. Measure voltage between terminal 7 of TPS harness connector and chassis ground.

Specification : Approx. 5 V

d. Is the measured voltage within specification?

YES - Go to "Check short to battery in harness" as follows.

NO - to "Check open in harness" as follows.

2. Check open in harness
a. IG "OFF" and disconnect TPS connector and PCM connector.




b. Measure resistance between terminal 7 of TPS harness connector and terminal 48 of PCM harness connector.

Specification : Below 1 ohm

c. Is the measured resistance within specification?

YES - Go to "Ground Circuit Inspection" procedure.

NO - Repair open in harness, and go to "Verification of Vehicle Repair" procedure.

3. Check short to battery in harness
a. IG "OFF" and disconnect TPS connector and PCM connector.
b. Measure resistance between terminals 4 and 7 of TPS harness connector.
c. Measure resistance between terminals 1 and 7 of TPS harness connector.
d. Measure resistance between terminals 2 and 7 of TPS harness connector.




e. Measure resistance between terminals 3 and 7 of TPS harness connector.

Specification : Infinite

f. Is the measured resistance within specification?

YES - Go to "Ground circuit inspection " procedure.

NO - Repair short to battery in harness, and go to "Verification of Vehicle Repair" procedure.

GROUND CIRCUIT INSPECTION
1. IG "OFF" and disconnect TPS connector.
2. IG "ON" and ENG "OFF"
3. Measure voltage between terminal 4 of TPS harness connector and chassis ground.




4. Measure voltage between terminals 4 and 8 of TPS harness connector.

Specification : Voltage difference between measurement "A" and "B" is below 200 mV.

5. Is the measured voltage within specification?

YES - Go to "Component inspection" procedure.

NO - Repair open or contact resistance in harness, and go to "Verification of Vehicle Repair" procedure.

COMPONENT INSPECTION
1. Check TPS
a. IG "OFF" and disconnect TPS connector.




b. Measure resistance between terminals 4 and 5 of TPS connector.(component side)

Specification :4 - 6k ohms.

c. Is the measured resistance within specification?

YES - 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.

NO - 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.

CAUTION: 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 sec.)
- Turn ignition key on more than 1 second to record the throttle motor position on the EEPROM

VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1. Monitor and record the Freeze Frame Data for the Diagnostic Trouble Code(DTC) which has been diagnosed.
2. Using a Scantool, Clear the DTCs
3. Operate the vehicle within conditions noted in the freeze frame data or enable conditions
4. Monitor that all readiness test have been verified as "Complete".
5. Are any DTCs present?

YES - Go to the applicable troubleshooting procedure.

NO - System is performing to specification at this time.