0327342 JOHNSON ORIFICE, Idle, no. 46

Table 2
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Connect Cat® Electronic Technician (ET) to the service tool connector.
B. Determine if a code is active or logged.
Codes
Result: A -7 code is active.
Proceed to Test Step 2.
Result: A -12,-13, or -14 code is active.
Proceed to Test Step 3.
Result: A -8 code is active.
Proceed to Test Step 4.
Result: A -3 or -4 code is active.
Proceed to Test Step 7.
2. Check for Debris
A. Set the engine control to the OFF/Reset mode.
B. Inspect the fuel actuator valve bore for debris.
Debris
Result: No debris or problem was found in the fuel actuator valve bore.
Proceed to Test Step 3.
Result: Debris or a problem contributing to proper valve operation was detected.
Repair: Remove the debris and remedy the cause of binding.
3. Cycle Battery Power
A. Turn the main disconnect t switch to the OFF position for at least 30 seconds.
B. Turn the battery disconnect switch to the ON position.
Cycle Power
Result: A -7,-12, -13, or -14 code is active after cycling power to the device.
Repair: Replace the fuel actuator valve.
Result: The active diagnostic has transitioned to logged.
There may have been an intermittent electrical problem with the actuator. If diagnostic code continues to return to an active status, replace the fuel actuator valve.
4. Check the Wiring Harness for an Open Circuit
A. Turn the main disconnect switch to the OFF position.
B. Disconnect the AC-C1 wiring harness connector from the Electronic Control Module (ECM) housing.
C. Disconnect the fuel actuator valve connector.
D. Measure the resistance between the following locations:
- Terminal 3 (PWM +) of the fuel actuator valve connector and terminal 1 of the AC-C1 ECM connector
- Terminal 4 (PWM -) of the fuel actuator valve connector and terminal 2 of the AC-C1 ECM connector
Open Circuit
Result: Both measurements were less than 10 ohms between the connector terminals.
Proceed to Test Step 5.
Result: One or more of the measurements were greater than 10 ohms between the connector terminals.
Repair: An open circuit has been detected. Repair or replace the wiring harness.
If the problem is not resolved, proceed to Test Step 5.
5. Check the Wiring Harness for a Short Circuit to Ground
A. Turn the main disconnect switch to the OFF position.
B. Disconnect the AC-C1 wiring harness connector from the ECM housing.
C. Disconnect the fuel actuator valve connector.
D. Measure the resistance between the following locations:
- Terminal 3 (PWM +) of the fuel actuator valve connector and engine ground.
- Terminal 4 (PWM -) of the fuel actuator valve connector and engine ground.
Short Circuit
Result: Both measurements were greater than 100 K ohms between the fuel actuator valve connector terminal and engine ground.
Proceed to Test Step 6.
Result: One or more of the measurements were less than 100 K ohms between the fuel actuator valve connector terminal and engine ground.
Repair: There is a short circuit in the wiring harness. Repair or replace the wiring harness.
If the problem is not resolved, proceed to Test Step 6.
6. Check the Wiring Harness for a Short Circuit
A. Turn the main disconnect switch to the OFF position.
B. Disconnect the AC-C1 wiring harness connector from the ECM housing.
C. Disconnect the fuel actuator valve connector.
D. Measure the resistance between the following locations:
- Connector AC-C1 terminal 1 (PWM +) and all other ECM connector terminals.
- Connector AC-C1 terminal 2 (PWM +) and all other ECM connector terminals.
Short Circuit
Result: One or more of the measurements were less than 100 K ohms between a connector terminal and any other terminal in the ECM connector.
Repair: There is a short circuit in the wiring harness. Repair or replace the wiring harness.
Verify that the repair eliminated the problem.
Result: All of the measurements were greater than 100 K ohms between a connector terminal and any other terminal in the ECM connector.
Repair: Contact the DSN for further assistance. The ECM and Fuel Metering Valve are unlikely components to fail with a -8 FMI code. A wiring problem or unique component failure is possible.
7. Check the Battery Voltage at the Device
A. Turn the main disconnect switch to the on position.
B. Start the engine.
C. Insert 7X-1710 Multimeter Probes into the following locations:
- Terminal 1 of the fuel actuator valve connector AC-C15.
- Terminal 2 of the fuel actuator valve connector AC-C15.
D. Measure the battery voltage between connector terminals 1 and 2.
Voltage
Result: The voltage measurement is 24 4 VDC.
Battery supply voltage is OK. The problem may be intermittent. Verify the charging circuit is operating properly.
Refer to Troubleshooting , Alternator Problem.
Result: The voltage measurement is 30 VDC or greater.
Repair: There is a problem with the charging circuit. Refer to Troubleshooting , Alternator Problem and Special Instruction , Battery Test Procedure.
Result: The voltage measurement is 18 VDC or less.
Proceed to Test Step 8.
8. Check the Battery Voltage at the Batteries.
A. Turn the main disconnect switch to the on position.
B. Start the engine.
C. Measure the battery voltage at the batteries.
Voltage
Result: The voltage measurement is 24 4 VDC.
There is a partial open or high resistance in the wiring between the fuel metering valve and the batteries resulting in a voltage drop.
Repair: Repair or replace the wiring.
Result: The voltage measurement is 18 VDC or less.
Repair: There is a problem with the charging circuit. Refer to Troubleshooting , Alternator Problem and Special Instruction , Battery Test Procedure.
If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).