881201 2 Mercury WATER TUBE, (18.21 Inches) (X-Long)

Table 1
Diagnostic Codes Table
J1939 Code and Description Conditions which Generate this Code System Response
677-5 Engine Starter Motor Relay : Current Below Normal The engine Electronic Control Module (ECM) detects an open in the circuit for the starter relay.
The ECM detects a short to battery voltage in the circuit for the starter relay.
The ECM can only detect this condition when the output driver is not activated. The code is logged.
677-6 Engine Starter Motor Relay : Current Above Normal The ECM detects a short in the circuit for the starter relay.
The ECM can only detect this condition when the output driver is activated. Use this procedure to troubleshoot the electrical system if a problem is suspected with the starting system.The ECM is provided with the ability to begin the engine cranking at any time after the ECM has received keyswitch power. The ECM receives the start command from the EMCP via the global CAN data link. Once this request is received, the engine is placed into the "Prestart State" of the control for the engine state. If the engine is equipped with a prelubrication system, the engine will wait until the prelube cycle has been completed before initiating engine cranking.Configuration ParametersThe settings of the following configuration parameters control engine starting:
Starting System #1 Maximum Number of Crank Cycles
Starting System #1 Crank Duration
Crank Terminate RPM
Illustration 1 g02684456
Schematic for the engine starting system
If applicable, there are also configuration parameters that are used to configure the ECM for the type and the location of the starting motors. The following types of starting motors may be available for this engine:
Air starting motor
Electric starting motor
Hydraulic starting motorThe wiring for each of these types of engine starting circuits is similar. Follow this procedure in order to troubleshoot the circuit diagnostics for any of these types of engine starting system.If applicable, the ECM can control a secondary starting system installed on the opposite side of the engine from the primary starting system. Refer to Troubleshooting, "Configuration Parameters" for information that is related to the configuration parameters that are for the secondary starting system.ECM Activation of the Starting MotorsThe ECM utilizes two output drivers in order to crank the engine. Each output driver is provided with 24 VDC during engine cranking. The circuits for the output drivers utilize a return line to the ECM. This circuit includes crank relays that can be powered by an external power supply in order to override the ECM activation of the starting motors.Manual Overrides for the Engine Starting SystemThe engine can be manually cranked by using a manual crank switch that can be wired into the engine interface connector.Caterpillar Electronic Technician (ET) can be used in order to override the output command that is provided by the engine state control. Overriding the output command can be used to diagnose the circuit that is for the starting motor magnetic switches. View the "Starting System Relay Status" that is available in Cat ET in order to determine the status of the ECM outputs.Test Step 1. Inspect the Electrical Connectors and the Wiring
Turn the main disconnect switch to the OFF position.
Thoroughly inspect all of the connectors that are associated with the circuit. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Illustration 2 g02721290
Location of the J1/P1 and the J2/P2 ECM connectors (typical engine view)
(1) J1/P1 ECM connector
(2) J2/P2 ECM connector
Illustration 3 g02706411
Terminal locations at the P2 ECM connector for the engine starting system
(P2-60) Right starter enable −
(P2-59) Right starter enable +
(P2-51) Left starter enable +
(P2-43) Left starter enable −
Illustration 4 g02751118
Terminal locations at the right rail connector for the engine starting system
(35) Right starting motor magnetic switch +
(34) Right starting motor magnetic switch −
Illustration 5 g02751118
Terminal locations at the left rail connector for the engine starting system
(35) Left starter starting motor magnetic switch +
(34) Left starter starting motor magnetic switch −
Illustration 6 g01827275
Terminal locations at the power interface connector
(29) Left starter enable +
(30) Left starter enable −
Illustration 7 g01533453
Terminal locations at the keyswitch relay and the relay for the power mode circuit
(Terminal 1) Power to the starting motor magnetic switch
(Terminal 2) Power from the override switch that is used to override the ECM signal
(Terminal 3) Signal line or return line from the ECM
(Terminal 4) Power or return for the secondary circuit of the relay that is for the manual override
(Terminal 5) Return for the control circuit of the relay
Illustration 8