286547 Force KNOB CHOKE

Systems Operation
This area is used to describe subsystem component operation and other pertinent details for troubleshooting. Control or Sensor SignalsThe input and/or output signals are discussed in this area. Generally, each signal is discussed with specifications. Control DiagnosticsAny control diagnostics which directly relate to the component are briefly discussed. Engine or control response due to a diagnostic code may also be discussed. There are two basic wiring arrangements used on G3600 engines. The early engines used hard conduit on the engine and the engine mounted junction box terminals were labeled from 101 to 458. The later engines used individual flexible stainless steel harnesses and the junction box terminals were labeled from 610 to 958. The later version has been upgraded over time to include the Caterpillar Ignition System (CIS), Detonation Mixing Control (DMC), and the Hydrax actuators. The harnesses and junction box termination labels have remained essentially the same with necessary hardware additions and deletions. The schematics in this publication show only the later version terminal points. For the early versions reference the Electrical Schematics for termination points. Diagnostic Codes
Inspecting Electrical Connectors
Test Procedure 1
Many of the System Troubleshooting Procedures in this manual will recommend checking a specific electrical connector. The following procedure will assist in the examination of the connector to determine if it is the cause of the problem. If a problem is found in the electrical connector or connection, repair it if possible. If it cannot be repaired, replace the faulty connector or wiring harness.DO NOT cut the Deutsch connector wires if the connector must be replaced, The Deutsch Style connectors are repairable without the need to cut the wires. New pins and sockets can be inserted with a crimp tool. Wiggle the wires while the engine is running to reveal any intermittent diagnostic codes. Clean electrical connections with an alcohol based cleaner when any connector is unmated in a dirt environment. Turn the Mode Control Switch (MCS) to the OFF/RESET position and open the fuse breaker in the ESS panel before doing wiring checks or disconnecting any harnesses. Deutsch Connectors Functional Test
DDT Troubleshooting
System Operation
The Digital Diagnostic Tool (DDT) provides status information for the Engine Supervisory System (ESS). The DDT communicates directly with the Engine Control Module (ECM) over the CAT Data Link. The DDT is the interface used to display ESS Control System status information of engine operating conditions such as engine speed, detonation, inlet manifold pressure, and ignition timing. The DDT is also used for programming the ESS Control System to match performance requirements.The DDT operates on Battery voltage. The battery voltage is supplied to the DDT at the same time voltage is applied to the ESS Control Module.Two communication wires between the DDT and the ESS panel carry the information.The DDT Service Tool can be connected to the ESS System at the Service Tool Connector on either The Engine Mounted Terminal Box or the ESS Panel. Do not connect more than one DDT Service Tool at a time.Figure 1: DDT Diagram Figure 2: DDT Communications Components Using 7X-1400 Tool Gp. Figure 3: DDT Wiring Schematic Diagnostic Codes
Functional Test
SCM Speed Sensor
System Operation
The SCM Engine Speed Sensor (MPU) is a passive magnetic pickup sensor that provides engine speed to the SCM.The Engine Speed Sensor must be installed with an air gap of one half to three fourths counterclockwise turn from full bottom position. A properly adjusted air gap will prevent nuisance diagnostics. The sensor is shared with the Timing Control Module (TCM) and DMC where applicable.The sensor outputs a sinusoidal waveform created as the flywheel ring gear teeth pass beneath the pickup. The frequency of the signal is proportional to the speed of the engine. The signal can be interpreted as engine speed (rpm) equals frequency (Hz) multiplied by 60 then divided by the number of teeth (255). rpm=(Hz) X 60 / (255)The frequency of the signal can be measured using a voltmeter with an AC frequency mode or an oscilloscope. Figure 2: SCM Speed Sensor Schematic Figure 3: Speed Sensor Output Table Diagnostic Codes
Functional Test
Oil Pressure/Temperature Module
System Operation
The SCM monitors the oil pressure and oil temperature to provide basic engine protection.The Oil Pressure/Temperature Module (or Transducer Module) receives engine oil pressure sensor and oil temperature sensor values and relays the information to the SCM.The sensor module sends the engine oil temperature and pressure information to the SCM in a serial communications message.Figure 1: Oil Pressure/Temperature Module Diagram Figure 2: Oil Pressure/Temperature Module Schematic Refer to the Electrical Schematic for the terminations.Diagnostic Codes
Functional Test
Mode Control Switch (MCS)
System Operation
The Status Control Module (SCM) uses the Mode Control Switch (MCS) to control the starting and stopping functions for the engine.Placing the Mode Control Switch (MCS) to the OFF/RESET position is used to clear and reset diagnostic fault codes.The SCM input is connected to ground by the MCS to determine the MCS switch position.This diagnostic code will be active if there is an open or short from the Mode Control Switch (MCS) to the SCM. At least one input (AUTO, START, STOP or OFF/RESET) must be connected to -Battery. Figure 2: Mode Control Switch Schematic