Skip to main content

VMI3 Basic Usage Guide: Engine Coolant Temperature Sensor (ECTS) Dual Display Analysis and Simulation

Oscar Eom
Updated

This guide explains how to use the Dual Display function of the GDS Smart VMI3 to measure the voltage of the Engine Coolant Temperature Sensor (ECTS), and how to output a simulated voltage signal from the VMI3 to check for changes in the ECU's temperature recognition.

Guide Video

Step 1: Preparation and Probe Connection

  • Test Vehicle: KONA (SX2) G1.6 T-GDI
  • Measurement Target: Engine Coolant Temperature Sensor (ECTS)
  • Probe Connection (Channel B):
    • (+) Probe: Connect to Pin 12 (Sensor Signal Line) of the ECTS connector.
    • (-) Probe: Connect to the battery (-) terminal (vehicle body ground).
  • Measurement Condition: Proceed with the engine not started, in [IG ON] state.

Step 2: Dual Display - Checking Voltage Value Synchronization

Compare the sensor voltage (data) recognized by the ECU and the actual voltage measured by the VMI3 hardware (multimeter).

  • In the Dual Display menu, activate [데이터 분석(Data Analysis)] and [멀티미터(Multimeter)].
  • Data Analysis: Select the 'Water Temperature Voltage' item.
  • Multimeter: Set to 'Voltage' measurement mode and check whether the two voltage values match. (For example: confirm both show 2.65V)

Step 3: Simulation - Outputting Virtual Voltage

Force a voltage change with the VMI3 to test whether the ECU calculates the temperature correctly.

  • Change the lower screen to [시뮬레이션(Simulation)] mode and set the output method to 'Voltage Output'.
  • Checking ECU Response to Voltage Changes (NTC Characteristics):
    • VMI3 output 1.5V ➔ Data analysis temperature displays about 45.8°C
    • VMI3 output 1.0V ➔ Data analysis temperature displays about 58.5°C (Temperature rises as voltage decreases)
    • VMI3 output 0.3V ➔ Data analysis temperature displays about 95.2°C

💡 Troubleshooting Tips

With this simulation, you can check the circuit with only the wiring and ECU remaining, excluding the sensor. If the diagnostic tool's temperature data does not change even after changing the output voltage from the VMI3, you can determine that it is not a sensor failure but a disconnection/short in the wiring from the sensor to the ECU or a failure in the ECU internal module.

Related to

Related articles

Comments

0 comments

Article is closed for comments.