Description
PAI 350599 is an aftermarket engine oil pressure sensor for Caterpillar 3406E, C10, and C12 on-highway engines — a direct replacement for Cat 161-9930, 111-2350, 141-4121, and 3E-7570. The 3-pin, 3-wire sensor uses a 7/16″-20 thread and a 16.5″ pigtail to reach the dash and ECM. A failing oil-pressure sensor commonly throws low-pressure derate codes even on a healthy engine, so verify the sensor before tearing into the lube system.
Signs You Need a New Oil Pressure Sensor
- Low oil pressure warning lamp with no actual oil-pressure issue
- Erratic dash gauge readings or oil-pressure fault codes
- Engine derate or shutdown triggered by oil-pressure signal
- Visible oil leak at the sensor body or harness connector
Specifications
| Manufacturer | PAI Industries |
|---|---|
| Part Number | 350599 |
| Part Type | Engine oil pressure sensor |
| Engine Compatibility | Caterpillar 3406E, C10, C12, 3176B |
| Pin Count | 3 |
| Wire Count | 3 |
| Thread Size | 7/16″-20 |
| Overall Length | 16.5 in |
| Connector | Triangular |
Cross References
This part replaces or is equivalent to the following part numbers:
- Caterpillar: 161-9930, 1619930, 111-2350, 1112350, 141-4121, 1414121, 3E-7570, 3E7570
- PAI Industries: 350599, CAP350599
- Automann: 577.9953
Applications
Fits Caterpillar mechanical and ACERT-era heavy-duty engines through the C10/C12 family:
- Caterpillar 3406E 14.6L
- Caterpillar C10 10.3L
- Caterpillar C12 12L
- Caterpillar 3176B (selected applications)
Representative trucks using these engines:
- Freightliner Classic, Century, Columbia, FLD, Coronado (Cat-powered)
- Kenworth W900, T600, T800 (Cat-powered)
- Peterbilt 379, 378, 387 (Cat-powered)
- International 9200, 9400, 9900 (Cat-powered)
- Western Star 4900 (Cat-powered)
Verify thread size (7/16″-20), pin count (3), and the existing CAT part number before ordering. Replace the sensor O-ring on installation.









