The Electronic Throttle Control(ETC) system is made of the components throttle body, Throttle Position Sensor(TPS)1&2 and Accelerator Position Sensor(APS) 1&2. The throttle body contains the actuator, the throttle plate and the throttle position sensor (potentiometer), which are integrated in one housing. The actuator consists of a DC motor with a two-stage gear. The opening angle of the throttle valve is detected by the throttle position sensor which is mounted on the throttle body. And it provides feedback to the ECM to control the throttle motor in order to control the throttle valve opening angle properly in response to the driving condition.
Comparing real intake air flow and the intake air flow calculated by ETS under detecting condition, if the air flow more than threshold value is detected for more than 19 sec., PCM sets P2173. And then MIL(Malfunction Indication Lamp) turns on.
Item | Detecting Condition | Possible Cause | |
DTC Strategy | ● Monitor the measured engine airflow and the estimated airflow | ● Air Leakage between TPS and MAFS ● Faulty throttle body or intake manifold ● Faulty MAFS | |
Enable Conditions | ● Engine running ● No faults present | ||
Threshold | Case 1 | ● MAPS reading - ETC estimated airflow > 9 g/s | |
Case 2 | ● MAFS reading - ETC estimated airflow > 7g/s | ||
Diagnosis Time | ● Continuous (Within 20 sec.) | ||
MIL On Condition | ● 1 Driving Cycle |
Air flow (kg/h) | Frequency (Hz) |
0 kg/h | 720 ~ 880 Hz |
12.6 kg/h | 2,595 Hz |
18.0 kg/h | 2,930 Hz |
23.4 kg/h | 3,208 Hz |
32.4 kg/h | 3,609 Hz |
43.2 kg/h | 3,975 Hz |
57.6 kg/h | 4,361 Hz |
72.0 kg/h | 4,683 Hz |
108.0 kg/h | 5,362 Hz |
144.0 kg/h | 5,885 Hz |
198.0 kg/h | 6,527 Hz |
270.0 kg/h | 7,219 Hz |
360.0 kg/h | 7,945 Hz |
486.0 kg/h | 8,736 Hz |
666.0 kg/h | 9,660 Hz |
900.0 kg/h | 10,613 Hz |
Throttle opening (°) | Output voltage(V) [Vref=5.0V] | |
TPS1 | TPS2 | |
0° | 0.0V | 5.0V |
10° | 0.5V | 4.5V |
V20° | 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 |
Pressure(kPa) | Output voltage(V) |
20.0kPa | 0.79V |
35kPa | 1.382V |
46.66kPa | 1.84V |
60kPa | 2.369V |
90kPa | 3.75V |
101.32kPa | 4.00V |
Check DTC Status
Connect scantool to Data Link Connector(DLC).
IG "ON".
Select "Diagnostic Trouble Codes(DTCs)" mode, and then Press F4(DTAL) to check DTC's information from the DTCs menu
Read "DTC Status" parameter.
Is parameter displayed "Present fault"?
▶ Go to "System inspection" procedure.
▶ 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.
Visual Inspection
Check the air hose between MAFS and throttle body is torn or installation.
Check deforamtion, crack or installation of throttle valve(body)
Has a problem been found ?
▶ Substitute with a known-good Air hose or throttle body and check for proper operation. If the problem is corrected,replace air hose or throttle body and then go to "Verification of Vehicle Repair" procedure.
▶ Go to "Check MAFS" as follows.
Check MAFS
IG "OFF" and install a scantool
ENG "ON" and monitor "MAFS" data on the service data.
Monitor signal waveform at terminal 1 of MAFS with scantool.
Specification :Signal waveform will be displayed as follows.
(Be aware that the signal of MAFS is not voltage display but frequency display.)
Are both service data and signalwave form dispayed correctly ?
▶ Go to "Verification of Vehicle Repair" procedure.
▶ Substitute with a known - good MAFS and check for proper operation. If the problem is corrected, replace MAFS and go to "Verification of Vehicle Repair" procedure.
After a repair, it is essential to verify that the fault has been corrected.
Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode
Press F4(DTAL) and confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions
Read "DTC Status" parameter
Is parameter displayed "History(Not Present) fault"?
▶ System performing to specification at this time. Clear the DTC.
▶ Go to the applicable troubleshooting procedure.