I. Basic Parameters

Voltage: DC 12V (No 24V version available; the HC0119 model in the same series is a separate product variant.)

Plug: Dual-wire harness plug (Black square socket + White plug); features a single-lug mounting hole on the housing for direct installation.

Replacement: Replaces OEM Part No. 128300-77920 (Model HC0108); serves as the genuine Yanmar-matched pre-heating safety module.

II. Compatible Yanmar Engines

3TNV88, 4TNV94, 4TNV94L, and 4TNV98—the entire series of diesel engines.

III. Compatible Machinery (Primary applications: Mini-excavators / Forklifts)

Excavators: Hyundai R55/R60-7, XCMG 60, SANY 55/60, Sunward, and LiuGong 906 mini-excavators (powered by Yanmar 4TNV94 engines).

Internal Combustion Forklifts: Heli and Hangcha 2–3 ton forklifts (powered by 4TNV98 engines).

Agricultural Machinery / Loaders: Harvesters and small loaders equipped with Yanmar TN-series engine models.

IV. Three Key Functions

Cold-Start Pre-heating Timer: Controls the delayed heating of glow plugs under low-temperature conditions to improve cold-starting performance.

RPM-Locked Starting: Detects alternator RPM once the engine fires up to cut off the pre-heating circuit; locks out the starter circuit after engine shutdown to prevent accidental starter engagement and damage to the flywheel ring gear.

Delayed Shutdown Power Cutoff: Delays the fuel cutoff (engine shutdown) for a brief period after the ignition key is turned off; designed to work in conjunction with Yanmar shutdown solenoid valves.

V. Common Faults

Pre-heating indicator light remains constantly on; glow plugs burn out: Internal timing chip is damaged.

Pre-heating functions normally, but the starter motor does not respond when the key is turned: RPM detection circuit failure.

Fuel supply cuts off immediately upon shutdown; unable to perform the delayed idle shutdown sequence: Relay failure.