0392171 JOHNSON EXHAUST HOUSING, Outer

Table 1
Diagnostic Codes Table
Description Conditions which Generate this Code System Response
18-8 Fuel Control Valve : Abnormal Frequency, Pulse Width, or Period The controller for the fuel control valve has detected an error at the input for the Pulse Width Modulated signal (PWM). The problem is communicated to the Electronic Control Module (ECM) via the CAN data link. Control for the fuel control valve reverts to the CAN data link.
18-9 Fuel Control Valve : Abnormal Update Rate The engine ECM did not receive the expected data link information from the controller for the fuel control valve. Control for the fuel control valve reverts to the PWM signal.
1028-6 Power Supply Control 1 : Current Above Normal The ECM output which powers the Fuel Control Valve has detected a short to ground in the wiring or an internal fault with the fuel control valve. Engine will be unable to build rail pressure This engine is equipped with a high pressure common rail fuel system. The fuel pressure for the high pressure common rail fuel system is generated by the high-pressure fuel pump. Output pressure regulation for the high-pressure fuel pump is provided by the fuel control valve. The fuel control valve is a mechanical valve that is part of the high-pressure fuel pump. The valve regulates the fuel pressure that is produced by the pump by controlling the volume of fuel that enters the pump. The valve is controlled by an electrical actuator. Control for the actuator is provided by an electronic controller that is part of the actuator.The engine ECM communicates a desired throttle position to the controller for the fuel control in the form of a PWM signal. The PWM signal is generated by a signal driver at the ECM and the signal is sent to the controller for the fuel control valve.Note: The desired throttle position is also communicated via the CAN data link as a throttle backup control.The PWM signal that is used for the desired throttle position has a constant frequency of 500 Hz. At low engine idle, the signal will have a duty cycle of approximately 10 percent. At high engine idle with no load on the engine, the signal will have a duty cycle of approximately 20 to 25 percent. At high engine idle with a full load on the engine, the signal will have a duty cycle of approximately 50 to 60 percent.The desired throttle position can be viewed on Caterpillar Electronic Technician (ET). View the status of the "Fuel Actuator Position Command" parameter in order to determine the desired throttle position of the engine. At low engine idle, the "Fuel Actuator Position Command" will be approximately 10 to 15 percent. At high engine idle with no load on the engine, the "Fuel Actuator Position Command" will be approximately 20 to 25 percent. At high engine idle with a full load on the engine, the "Fuel Actuator Position Command" will be approximately 40 to 50 percent.the ECM supplies a filtered battery voltage to the controller for the fuel control valve. The supply to the controller is filtered in order to suppress voltage spikes that can damage the controller.
Illustration 1 g02453052
Schematic of the PWM signal (primary throttle control) for the high-pressure fuel pump
Note: For a schematic and troubleshooting information that is related to the throttle backup control and the CAN data link, refer to Troubleshooting, "Data Link - Test".
Illustration 2 g02453072
Location of the connectors at the control box that are for the fuel control (typical top front engine view)
(1) Right rail connector
(2) J1/P1 ECM connector
(3) Engine interface connector at the control box
(4) Relay for the keyswitch circuit
(5) Control box connector to the low current power distribution panel
Illustration 3 g02453075
Location of the low current power distribution panel (front left side engine view)
(6) Harness to the low current power distribution panel
(7) Low current power distribution panel
Illustration 4 g02453078
Location of the connectors at low current power distribution panel (7) for the primary throttle control
(8) Gray connector
(9) Brown connector
(10) Fuse for the keyswitch circuit
(11) −Battery
(12) +Battery
Illustration 5 g02453081
Location of the connectors at the high-pressure fuel pump
(13) Connector for the controller at the fuel control valve
Illustration 6 g01318105
Terminal locations for the high-pressure fuel pump at the P1 ECM connectors
(P1-38) PWM signal
(P1-70) Keyswitch
Illustration 7 g02453085
Terminal locations for the high-pressure fuel pump at the P2 ECM connectors
(P2-6) Filtered +Battery
Illustration 8 g01477832
Terminal locations for the high-pressure fuel pump at the right rail connectors
(Terminal 16) Filtered +Battery from the ECM
(Terminal 17) Return circuit from −Battery
(Terminal 48) PWM signal
(Terminal 70)