825667 Mercury CDI UNIT

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Turbochargers (1) Turbocharger on C7 engines with less than 330 hp (2) Turbocharger on C7 engines with 330 hp or more, and on C9 enginesThe following information applies to the turbochargers on these engines:Turbochargers on C7 engines with less than 330 hp have a hydraulic actuator and a speed sensor. The actuator receives a pulse width modulated command (PWM) from the ECM. The actuator uses pressurized engine oil to convert the PWM command into movement of the vanes inside the turbine housing. Movement of the vanes causes the boost pressure to change. The speed sensor creates a speed signal for the ECM.Turbochargers on C7 engines with 330 hp or more, and on C9 engines have an electronic actuator and a speed sensor. The actuator receives electrical power that is provided by the OEM via a breakout on the engine harness. The actuator receives commands from the ECM via the CAN data link. The actuator converts the commands into movement of the vanes inside the turbine housing. Movement of the vanes causes the boost pressure to change. The actuator sends status information to the ECM via the CAN data link. The speed sensor creates a speed signal for the ECM.Table 1 lists the diagnostic trouble codes that apply to these turbochargers:
Table 1
List of Diagnostic Trouble Codes    
J1939 Code    Description    Diagnostic Code Information    
103-8 (1) (2)     Engine Turbocharger 1 Speed : Abnormal Frequency, Pulse Width, or Period     There is a problem with the speed signal from the turbocharger. The code is logged. A snapshot is taken. Engine power is derated. The active code is cleared if the speed signal returns to normal.    
103-16 (1) (2)     Engine Turbocharger 1 Speed : High - Moderate Severity (2)     The turbocharger speed has exceeded the high limit. The code is logged. A snapshot is taken. Engine power is derated. The active code and the derate are cleared when the speed of the turbocharger goes below the high limit.    
641-4 (2)     Engine Turbocharger Variable Geometry Actuator #1 : Voltage Below Normal     The electrical power for the actuator is too low. The code is logged. Engine power is derated. The active code and the derate are cleared if the voltage returns to the acceptable range.    
641-5 (1)     Engine Turbocharger Variable Geometry Actuator #1 : Current Below Normal     The current flow through the circuit for the PWM command is below the minimum range. This problem can be caused by an open circuit or by a short to ground on the "PWM -" wire. The code is logged. A snapshot is taken. Engine power is derated. The active code and the derate are cleared if the current flow returns to the acceptable range.    
641-6 (1)     Engine Turbocharger Variable Geometry Actuator #1 : Current Above Normal     The current flow through the circuit for the PWM command is above the acceptable range. This problem can be caused by the following conditions:
A short to + Battery on the "PWM +" or "PWM -" wire
A short to ground on the "PWM +" wire
A short circuit between the "PWM +" wire and the "PWM -" wire
A short circuit inside the actuator
The code is logged. A snapshot is taken. Engine power is derated. The active code and the derate are cleared if the current flow returns to the acceptable range.    
641-7 (2)     Engine Turbocharger Variable Geometry Actuator #1 : Not Responding Properly     The position of the movable vanes is incorrect. The code is logged. A snapshot is taken. Engine power is derated. The active code and the derate are cleared if the actuator returns to normal operation.    
641-9 (2)     Engine Turbocharger Variable Geometry Actuator #1 : Abnormal Update Rate     There has been no communication between the actuator and the ECM for at least one second. The code is logged. A snapshot is taken. Engine power is derated. The active code and the derate are cleared if communication is restored for at least 4 seconds.
This code is caused by one of the following conditions:
Loss of electrical power to the actuator
A problem with the CAN data link
A problem with the actuator    
641-12 (2)     Engine Turbocharger Variable Geometry Actuator #1 : Failure     There is an internal problem with the actuator. The code is logged. Engine power is derated. The active code and the derate are cleared if the actuator returns to normal operation.    
641-14 (2)     Engine Turbocharger Variable Geometry Actuator #1 : Special Instruction     The CAN data link is OK. However, some of the messages on the CAN data link from the actuator to the ECM have been incorrect or missing for at least 10 seconds. The code is logged. Engine power is derated. The active code and the derate are cleared if complete communication is restored.
This code is caused by a problem with the actuator.    
( 1 ) This code applies to turbochargers on C7 engines with less than 330 hp.
( 2 ) This code applies to turbochargers on C7 engines with 330 hp or more, and to turbochargers on C9 engines.
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Schematic for turbochargers on C7 engines with less than 330 hp
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Schematic for turbochargers on C7 engines with more than 330 hp and for turbochargers on C9 enginesTest Step 1. Determine the Diagnostic Code
Establish communication between the Caterpillar Electronic Technician (Cat ET) and the engine ECM. The communication adapter must be communicating on both data links in order to perform this procedure. Refer to Troubleshooting, "Electronic Service Tools" for additional information, if necessary.Note: The engine must be at idle speed for at least 30 seconds in order for all of the codes to be reported.
Determine the code that is present. Note the time of occurrence of the code.
Interview the operator. Determine if the operator felt an engine performance problem that occurred with the logged code.Troubleshoot the logged code only if the code can be related to an engine performance problem. Otherwise, clear