Use this procedure to troubleshoot the following diagnostic codes:
- 1442-9 Fuel Actuator #1 abnormal update rate
- 1442-11 Fuel Actuator #1 other failure mode
- 1442-12 Fuel Actuator #1 failure
The fuel actuator is an electronic actuator that is controlled by the Electronic Control Module (ECM) in order to ensure the correct position of the fuel valve in all conditions of engine operation.
The ECM and the fuel actuator communicate via the CAN data link. The ECM sends a command signal to the actuator. The actuator sends the following information to the ECM:
- Actuator position
- Heartbeat signal for the Customer Communication Module (CCM)
- Software version
- Internal fault diagnosis
If the ECM cannot communicate with the fuel actuator, the ECM activates a 1442-9 Fuel Actuator #1 abnormal update rate and the engine is shut down. A 1442-9 diagnostic code is probably caused by a problem with an electrical connector or a harness. The next likely cause is a problem with the actuator. The least likely cause is a problem with the ECM.
Terminating resistors must be connected to each end of the CAN data link. The terminating resistors improve the communication between the devices. If there is an intermittent diagnostic code for any of the devices that are connected to the CAN data link, be sure to check the terminating resistors. One of the terminating resistors is connected to a splice in the wiring harness near the J1/P1 ECM connector. The other terminating resistor is connected to a "T" inside the optional remote panel. If the engine is not equipped with a remote panel, the other terminating resistor will be connected at the far end of interconnect harness. Refer to the appropriate documentation for the site in order to determine the location of this resistor.
This troubleshooting procedure may generate additional diagnostic codes. Correct the cause of the original diagnostic code before continuing. You clear the diagnostic codes after the problem is resolved.
Illustration 1 | g01437366 |
Schematic for the circuit for the fuel actuator |
Test Step 1. Inspect the Electrical Connectors and the Wiring
- Remove electrical power from the ECM. Set the engine control to the OFF/RESET mode.
Note: For the following steps, refer to Troubleshooting, "Inspecting Electrical Connectors".
Show/hide tableIllustration 2 g01392585 Location of the components for the fuel actuator (typical left side engine view)
(1) J1/P1 ECM connectors
(2) Fuel actuator
(3) Interface box - Thoroughly inspect ECM connectors (1), the connectors for actuator (2), and the connectors at the interface box (3).
- Check the allen head screw for each of the ECM connectors for the proper torque.
Show/hide table
Illustration 3 g01391850 Terminal locations at the P1 ECM connector for the fuel actuator
(34) CAN data link −
(42) Shield
(50) CAN data link +Show/hide tableIllustration 4 g01392686 Terminal locations at the connector for the fuel actuator
(A) CAN Ident
(C) Shield for the CAN data link
(F) Keyswitch
(G) CAN data link−
(M) CAN data link+
(Q) −Battery
(Z) +BatteryShow/hide tableIllustration 5 g01392608 Terminal locations at the interface box for the throttle actuator
(7) Keyswitch
(9) −Battery
(F1) Main fuse (15 Amp)
(F2) Fuse for the throttle actuator (10 Amp) - Perform a
45 N (10 lb) pull test on each of the wires that are associated with the fuel actuator. - Check the wiring for abrasion and for pinch points from the fuel actuator to the ECM.
- Check the allen head screw for each of the ECM connectors for the proper torque.
Expected Result:
All of the connectors, pins, and sockets are connected properly. The connectors and the wiring do not have corrosion, abrasion, or pinch points.
Results:
- OK - The components are in good condition with proper connections. Proceed to Test Step 2.
- Not OK - The components are not in good condition and/or at least one connection is improper.
Repair: Perform the necessary repairs and/or replace parts, if necessary. Ensure that all of the seals are properly installed. Ensure that the connectors are properly engaged. Verify that the repair has eliminated the original problem.
STOP
Test Step 2. Check for Diagnostic Codes
- Establish communication between the Caterpillar Electronic Technician (ET) and the ECM. Refer to Troubleshooting, "Electronic Service Tools", if necessary.
- Look for the following diagnostic codes:
- 1442-9 Fuel Actuator #1 abnormal update rate
- 1442-11 Fuel Actuator #1 other failure mode
- 1442-12 Fuel Actuator #1 failure
Expected Result:
There is not an active diagnostic code for the fuel actuator at this time.
Results:
- OK - There is not an active diagnostic code for the fuel actuator at this time.
Repair: There does not seem to be an electrical problem with the fuel actuator. If one of the codes is logged, there may be an intermittent problem in the harness or in a connector. There may be a problem with one of the fuses in the circuit.
Check that electrical power is available at the throttle actuator. If an intermittent problem with the harness or a connector is suspected, refer to Troubleshooting, "Inspecting Electrical Connectors" for information that is related to troubleshooting intermittent electrical problems.
STOP
- Not OK - 1442-9 is active - The ECM has detected a problem with the communication between the ECM and the fuel actuator. Proceed to Test Step 4.
- Not OK - 1442-11 or 1442-12 is active - There is a problem with the fuel actuator.
Repair: Replace the fuel actuator. Verify that the problem is resolved.
STOP
Test Step 3. Check for Electrical Power at the Fuel Metering Valve
- Refer to Illustration 1. Measure the voltage for the fuel metering valve at the engine interface box.
The battery voltage must be between 18 V and 32 V in order for the fuel metering valve to operate correctly. If a problem exists, correct the problem before you continue.
- Remove electrical power from the ECM. Set the engine control to the OFF/RESET mode.
- Disconnect the harness connector for the fuel metering valve.
- Restore electrical power to the ECM. Set the engine control to the STOP mode.
- At the harness connector for the valve, measure the voltage between the following terminals:
- F and Q (keyswitch power)
- Z and Q (battery power)
Results:
- OK - Both voltages at the harness connector are within 2 V of the voltage at the engine power distribution box. Proceed to Test Step 4
- Not OK - At least one of the voltages are not within 2 V of the voltage at the engine power distribution box.
Repair: The fuel metering valve is not receiving the proper operating voltage. There is a problem in the harness or in a connector. Determine the cause of the excessive voltage drop. Perform the necessary repairs. Verify that the repair eliminates the original problem.
STOP
Test Step 4. Check the Connection for the Harness Identification
Note: In order for the device to be recognized as the fuel actuator terminal A, must be grounded.
- Disconnect the harness connector from the fuel actuator.
- Measure the resistance between terminals A and Q on the harness connector for the fuel actuator.
Results:
- OK - The resistance measurement is less than two ohms. The jumper wire for the harness identification is OK. Proceed to Test Step 5.
- Not OK - The resistance measurement is greater than two ohms. The jumper wire for the harness identification is not OK. Perform the necessary repairs. Determine if the problem is resolved. If the problem is not resolved, proceed to Test Step 5.
Test Step 5. Check the Resistance of the CAN Data Link at the Harness Connector for the Fuel Metering Valve
Note: When the resistance measures between 114 Ohms and 126 Ohms, one of the resistors is not properly connected into the circuit.
- Remove electrical power from the ECM. Set the engine control to the OFF/RESET mode.
- Disconnect the harness connector for the fuel metering valve.
- Measure the resistance between terminals M and G of the harness connector for the fuel metering valve.
Results:
- OK - The resistance is between 57 and 63 Ohms. Proceed to Test Step 6
- Not OK - The resistance is not between 57 Ohms and 63 Ohms.
Repair: Ensure that 2 termination resistors of the correct value are in place and properly connected to the circuit.
Proceed to Test Step 6
Test Step 6. Check the Resistance of the CAN Data Link at the P1 ECM Connector
Note: Some devices will be spliced into the harness at different locations. Therefore also verify the correct resistance at the ECM. The ECM is the device the components are communicating with and the device that is presenting the code. Measure resistance at the ECM and check for continuity with the suspect device on the data link.
- Remove electrical power from the ECM. Set the engine control to the OFF/RESET mode.
- Disconnect the ECM J1/P1 connectors.
- Measure the resistance between terminals P1-50 (CAN data link +) and P1-34 (CAN data link -).
Results:
- OK - The resistance is between 57 and 63 Ohms. Proceed to Test Step 7
- Not OK - The resistance is not between 57 Ohms and 63 Ohms.
Repair: Ensure that 2 termination resistors of the correct value are in place and properly connected to P1-50 and P1-34.
Proceed to Test Step 7
Test Step 7. Check the Continuity of the Wiring Harness for the CAN Data Link
- Use a multimeter to check for continuity between the points that are listed in Table 1.
Show/hide table
Table 1 P1-34 Terminal G of the harness connector for the fuel metering valve P1-50 Terminal M of the harness connector for the fuel metering valve
Results:
- OK - There is continuity between the terminals of the connectors. Proceed to Test Step 8.
- Not OK - There is an open circuit between the terminals of the connectors.
Repair: Perform the necessary repairs to the wiring and/or connectors. Replace parts, if necessary. Ensure that all of the seals are properly installed. Ensure that the connectors are properly engaged. Verify that the repair has eliminated the original problem.
STOP
Test Step 8. Check the Harness for a Short Circuit
- Measure the resistance between the points that are listed in Table 2. Be sure to wiggle the wires in the harnesses as you make each resistance measurement.
Show/hide table
Table 2 P1-34 All of the other terminals on the P1 connector Ground strap for the ECM P1-50 All of the other terminals on the P1 connector Ground strap for the ECM
Results:
- OK - Each check of the resistance indicates an open circuit. The harness is not shorted. Proceed to Test Step 9.
- Not OK - At least one check of the resistance indicates that there is continuity.
Repair: There is a short circuit in a harness. There may be a problem with a connector. Repair the wiring and/or the connector. Replace part, if necessary. Restore the wiring to the original configuration. Verify that the problem is resolved.
STOP
Test Step 9. Determine if the ECM is the Problem
- Remove electrical power from the ECM. Set the engine control to the OFF/RESET mode.
- Temporarily install a new ECM.
- Connect the fuel metering valve.
- Restore electrical power to the ECM. Set the engine control to the STOP mode.
- Check for proper operation.
Results:
- OK - The new ECM resolved the problem.
Repair: If the problem is resolved with the new ECM, install the original ECM and verify that the problem returns. If the new ECM operates correctly and the original ECM does not operate correctly, replace the original ECM. Refer to Troubleshooting, "ECM - Replace"
STOP
- Not OK - The new ECM did not resolve the problem. Proceed to Test Step 10
Test Step 10. Determine if the Fuel Metering Valve is the Problem
- Remove electrical power from the ECM. Set the engine control to the OFF/RESET mode.
- Temporarily install a new fuel metering valve.
- Restore electrical power to the ECM. Set the engine control to the STOP mode.
- Check for proper operation.
Results:
- OK - The new valve resolved the problem.
Repair: Permanently install the new fuel metering valve.
STOP
- Not OK - The problem is not resolved.
Repair: Retest the system.
STOP