- Marine Engine:
- C7 (S/N: M7A1-UP; C7D1-UP; M7G1-UP; C7X1-UP)
- C9 (S/N: X9X1-UP; X9Y1-UP)
- C-12 (S/N: K1M1-UP; 9HP1-UP)
- C12 (S/N: NFL1-UP; C1Z1-UP)
- C18 (S/N: WKB1-UP; PLE1-UP; CKH1-UP; C1J1-UP; P1N1-UP; P2N1-UP; JKX1-UP; NAX1-UP; NAY1-UP; J2K1-UP; T2P1-UP)
- C32 (S/N: RXB1-UP; RNC1-UP; RND1-UP; RNR1-UP; SLT1-UP; T3T1-UP; RNY1-UP; RNZ1-UP)
Note: Caterpillar does not supply a transmission neutral switch. The OEM or the dealer must remove the jumper that is supplied by Caterpillar in order to connect a customer provided transmission neutral switch.
Engines Without a Multi-Station Control System (MSCS)
Note: Not all Marine Engines have a panel or a box that is mounted on the engine. The start circuit "high side" will have a direct path to the Starter Motor Mag Switch (SMMS) on engines without a panel or a box.
Illustration 1 | g01963081 |
(1) Starter Motor Mag Switch (SMMS) (2) Electronic Control Module (ECM) (3) Jumper for the SMMS (4) Engine mounted control panel |
The solenoid of the SMMS is activated by circuit 722 and circuit 214. Circuit 722 is the positive side or the high side, and 214 is the negative side or the low side. The low side passes through a switch or a jumper that is provided by the customer on the 70-pin connector to the engine. The high side comes from a connection to the positive terminal of the battery to pin 29 of the customer connector. Also, the high side can come from the activation of the start circuit on the panel or the box that is mounted on the engine if one is present.
There are three pins on the customer connector that are required for the starting circuit to energize the solenoid of the SMMS. The customer must provide a momentary connection from the positive terminal of the battery to pin 29 for the high side. The customer must provide a jumper, or a normally open, closed in neutral gear position switch for the low side in order to be conducted to ground by the ECM circuit X995.
The low side is controlled by the ECM. With a low side that is controlled by the ECM, the SMMS can not activate if the engine is already running.
Note: C32 Engines with the following prefixes may not have the circuit for the interlock on the 70-pin customer connector: RND, RNE, RNR, RNX, RNY and RNZ
Engine With a Multi-Station Control System (MSCS) and a Marine Junction Box (MJB)
Illustration 2 | g01963113 |
(1) Starter Motor Mag Switch (SMMS) (2) Shutdown switch (3) Remote Start (4) ECM (5) Transmission neutral switch that is provided by the customer (6) Expansion for the MJB (port or starboard) (7) Marine Junction Box (MJB) (8) MJB interface with the ECM (port or starboard) (9) Circuit for the interlock (10) Return from the start relay |
If no transmission neutral switch is used a jumper must be in place in order to allow low side of the SMMS to complete the path to ground through circuit X995 to ECM.
Note: No other neutral safety is present within the Multi-Station Control System (MSCS).
Refer to A&I Newsletter, LEHM0021, "STARTER MOTOR MAG SWITCH (SMMS)" for further information.
NOTICE |
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The Powertrain Control Processor (PCP) is not aware of neutral status of the Marine Gear (Transmission). The circuit of the SMMS is the only method that is provided in order to prevent starting the engine when the transmission is in gear. |