18515-ZW6-000 Honda GUIDE, AIR EX. (Honda Code 6006746).

Table 1
J1939 Code and Description CDL Code and Description System Response
1076-8
Engine Fuel Injection Pump Fuel Control Valve : Abnormal Frequency, Pulse Width, or Period 18-8
Fuel Control Valve : Abnormal Frequency, Pulse Width, or Period The controller for the primary 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 primary fuel control valve reverts to the CAN data link.
1076-9
Engine Fuel Injection Pump Fuel Control Valve : Abnormal Update Rate 18-9
Fuel Control Valve : Abnormal Update Rate The engine ECM did not receive the expected data link information from the controller for the primary fuel control valve.
Control for the primary fuel control valve reverts to the PWM signal.
3414-8
Fuel Control Valve #2 : Abnormal Frequency, Pulse Width, or Period 3414-8
Fuel Control Valve #2 : Abnormal Frequency, Pulse Width, or Period The controller for the secondary fuel control valve has detected an error at the input for the PWM signal. The problem is communicated to the ECM via the CAN data link.
Control for the secondary fuel control valve reverts to the CAN data link.
3414-9
Fuel Control Valve #2 : Abnormal Update Rate 3414-9
Fuel Control Valve #2 : Abnormal Update Rate The engine ECM did not receive the expected data link information from the controller for the secondary fuel control valve.
Control for the secondary fuel control valve reverts to the PWM signal. 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 Cat® 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.
Illustration 1 g02574400
Schematic of the PWM signal (primary throttle control) for the high-pressure fuel pump if equipped with A4 ECM
Illustration 2 g06320758
Schematic of the PWM signal (primary throttle control) for the high-pressure fuel pump if equipped with A5 ECM
Illustration 3 g02576378
Schematic of the PWM signal (secondary throttle control) for the high-pressure fuel pump if equipped with A4 ECM
Illustration 4 g06320764
Schematic of the PWM signal (secondary throttle control) for the high-pressure fuel pump if equipped with A5 ECM
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".
Table 2
Troubleshooting Test Steps Values Results
1. Check for an Active Codes
A. Connect Cat ET to the service tool connector.
B. Restore the electrical power to the ECM.
C. Monitor the diagnostic codes on Cat ET. Check and record any diagnostic codes.
Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
D. Determine if a diagnostic code has occurred several times.
Note: A diagnostic code that is logged several times is an indication of an intermittent problem. Most intermittent problems are the result of a bad connection between a socket and a pin in a connector. An intermittent electrical problem can also exist as a bad connection between a wire and a terminal.
E. Look for one or more of the following diagnostic codes that are active or logged:
- 18-7
- 18-8
- 18-9
- 18-11
- 18-12
F. Remove the electrical power from the ECM.
Codes
Results: No diagnostic codes are active.
Repair: There may be an intermittent problem in the harness or in a connector. If an intermittent problem is suspected, refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct procedures for inspecting electrical connectors.
Results: The 18-7 diagnostic code is active.
Repair: The actual position and the desired position of the fuel actuator is not within specifications. Replace the fuel control valve.
Results: The 18-8 diagnostic code is active.
The controller detects a problem in the circuit for the PWM signal from the ECM.
Proceed to Test Step 6
Results: The 18-9 diagnostic code is active.
The ECM detects a problem with data link communications for the controller.
Proceed to Test Step 2
Results: The 18-11 diagnostic code or the 18-12 diagnostic code is active.
Repair: During a self test, the controller has detected an internal fault. Replace the fuel control valve.
2. Check the Supply Voltage at the Controller
A. Disconnect the connector at the fuel control valve.
B. Restore the electrical power to the ECM. Ensure that the keyswitch is in the ON position.
C. Use a multimeter to measure the supply voltage between terminal