Description
The PAI 050673 is a 4-pin coolant level sensor that replaces Cummins 4903489 (and the superseded 3612521 / 4383932) on Cummins L10, M11, ISM, and N14 engines. It threads into the upper coolant tank or recovery bottle and signals low coolant to the ECM so the engine can warn or derate before head temperatures climb.
Signs You Need a New Coolant Level Sensor
- Low coolant warning that won’t clear with a full system
- Intermittent coolant alarm that comes and goes with vibration
- Coolant fault codes with verified normal coolant level
- Visible cracking, corrosion, or seepage at the sensor body
Specifications
| Manufacturer | PAI Industries |
|---|---|
| Part Number | 050673 |
| Part Type | Coolant Level Sensor |
| Pin Count | 4 |
| Connector Shape | Oval |
| Thread Size | 1/4 in – 18 NPT |
| Overall Length | 3.93 in |
| Engine Compatibility | Cummins L10, M11, ISM, N14 |
Cross References
This sensor replaces or is equivalent to the following part numbers:
- Cummins: 4903489, 3612521, 4383932
- Mack (PAI alias): 4333-1673785C92, 1MR4299
- Navistar (PAI alias): 1673785, 1673785C91, 1673785C92
- Peterbilt (PAI alias): 86714A1
Applications
This coolant level sensor fits the following engines:
- Cummins L10
- Cummins M11
- Cummins ISM
- Cummins N14 (Celect / Celect Plus)
Verify sensor location, port thread, and connector pinout on your engine before ordering to confirm fitment.
