Engine Coolant Temperature Sensor (ECT)

Haltech HT-010300 Coolant Temperature Sensor Summary

This page provides detailed information about the Haltech HT-010300 Coolant Temperature Sensor used in the Honda RC51 custom ECU build, including its specifications, connector details, wiring, and visual references.

Haltech HT-010300 Coolant Temperature Sensor Overview

For the Engine Coolant Temperature (ECT) sensor, I chose to replace the OEM sensor with a Haltech HT-010300. This sensor matches the threads on the OEM housing, which are M12x1.5, and comprehensive voltage parameter documentation is readily available. While using the OEM sensor is possible, you would need to determine its resistance curve and input those values into FT Manager for the ECT input.

Haltech Coolant Temperature Sensor Specifications

Connector Data

The Haltech HT-010300 sensor uses a Delphi 2-Pin GM-style Coolant Temperature Connector (Part #HT-030411). The exact connector is the Delphi 12162193.

HT-010300 ECT Sensor Connector — Delphi 2-Pin GM-style Coolant Temperature Connector

IMPORTANT NOTE:

Pay careful attention to the connector you are provided with. The connector I received was not a pull-to-seat connector, contrary to what is stated on Haltech's website. However, I did receive the correct documentation with my purchased sensor. I recieved the rear-insert connector Delphi: 15449028. Always double-check the style of connector you are provided with.

Mounting the ECT Sensor

The threads on the OEM sensor are M12x1.5, which match those of the Haltech HT-010300. Mount the sensor in the OEM thermostat housing. No special modifications are required.

ECU Setup

ECU configuration for the Haltech HT-010300 sensor is straightforward, as FuelTech provides default configurations for this sensor. FuelTech includes a predefined GM Temperature Sensor (USA) configuration, which can be used. Alternatively, you could update the Custom Interpolation table with the values provided by Haltech, but as shown in the plot below, the voltage tables are nearly identical, and the FuelTech table offers greater resolution.

Open FT Manager.
Navigate to Sensors and Calibration.
Click on the Inputs tab.
Locate your Engine Temp input field.
Select the predefined sensor parameter, GM Temperature Sensor (USA).

Coolant Temperature Sensor Configuration — Configuring the FT Manager tune with ECT Sensor parameters

Wiring Diagram

The Haltech HT-010300 sensor uses a Delphi 2-Pin GM-style Coolant Temperature Connector with the following pinout: Pin A - Signal Ground, Pin B - Signal. Wiring is straightforward; refer to the Haltech manual for additional details if needed. You can use any available white input. Note: Connect the housing ground wire as normal to ground the thermostat housing (part of the Main Harness); this should not be omitted.

The ECT sensor is part of the Sensors sub-harness. Refer to that documentation for electrical integration and wiring of the ECT.

Coolant Temperature Sensor Images

Explore this collection of high-resolution images showcasing the Haltech HT-010300 Coolant Temperature Sensor and its installation.

Haltech GM Style ECT Sensor Documentation — Haltech GM Style ECT Sensor (Documentation)