| Connector | Function |
|---|---|
| J1/P1 | Electronic Control Module (ECM) connectors |
| J2/P2 | ECM connectors |
| J42 | Service tool connector (customer supplied) |
| J57/P57 | J1939 Terminating resistor (customer installed component) |
| J60 | Service tool connector (Caterpillar supplied) |
| J61/P61 | Customer connector |
| J67/P67 | J1939 Terminating resistor (Caterpillar installed) |
| J71/P71 | Marine Power Display |
| J94/P94 | Marine Engine Control Panel |
| J100/P100 | Engine coolant temperature sensor |
| J103/P103 | Inlet manifold air temperature sensor |
| J105/P105 | Fuel temperature sensor |
| J137/P137 | Transmission oil temperature sensor |
| J145/P145 | Fuel outlet temperature sensor ( C18 Only) |
| J200/P200 | Turbocharger outlet pressure sensor |
| J201/P201 | Engine oil pressure sensor |
| J209/P209 | Fuel pressure sensor |
| J212/P212 | Transmission oil pressure sensor |
| J300/P300 | Injector valve cover entry connector |
| P400 | Timing Calibration (TC) probe connector |
| J401/P401 | Primary engine speed/timing sensor |
| J402/P402 | Secondary engine speed/timing sensor |
| J403/P403 | Primary throttle position sensor |
| J404/P404 | Secondary throttle position sensor |
| J800/P800 | Engine coolant level sensor |
 | |
| Illustration 1 | g01153727 |
Block diagram for 3406E, C12, C15, and C18 | |
C12 Engine
 | |
| Illustration 2 | g01153927 |
C12 component locations (typical example) (1) Engine coolant level sensor (2) Fuel temperature sensor (3) Engine coolant temperature sensor (4) Turbocharger outlet pressure sensor (5) Connector for the transmission oil pressure (6) Connector for the transmission oil temperature (7) Inlet manifold air temperature sensor (8) Secondary engine speed/timing sensor (9) Primary engine speed/timing sensor (10) Engine oil pressure sensor (11) Fuel presssure sensor (12) ECM (13) J2/P2 ECM connector (14) J1 ECM connector | |
3406E, C15, and C18 Engines
 | |
| Illustration 3 | g01154016 |
3406E, C15, and C-18 component locations (typical example) (1) Engine coolant temperature sensor (2) Turbocharger outlet pressure sensor (3) J61 Customer connector (4) J63 Service tool connector (5) P300 Valve cover connector (6) Fuel temperature sensor (7) P400 Timing calibration connector (8) Intake manifold air temperature sensor (9) Connector for the transmission oil pressure sensor (10) Connector for the transmission oil temperature sensor (11) Primary engine speed/timing sensor (12) Secondary engine speed/timing sensor (13) Fuel presssure sensor (14) Atmospheric pressure sensor (15) Engine oil pressure sensor (16) ECM (17) J2 ECM connector (18) J1 ECM connector | |