The Engine Control Module (ECM) monitors the current flow through the coils on the following components:
- Air pressure control valve
- Fuel enable valve
- Pilot fuel control valve
- Main fuel control valve
- CGI control group
The ECM sets a diagnostic trouble code if the current flow through a coil is incorrect. Table 1 lists the diagnostic codes for incorrect current flow.
| Diagnostic Trouble Codes For the Solenoids | ||
|---|---|---|
| J1939 Code | Description | Comments |
| 3479-5 | Aftertreatment #1 Fuel Pressure Control : Current Below Normal | This code can be activated only when the ECM is not sending a command to the fuel control valves for the ARD. This code indicates that the current flow through the circuit is low. The ARD is disabled. The ECM periodically checks the circuit in order to determine if the low current condition still exists. The following conditions can cause this code: There is an open circuit in the wiring. There is an open circuit inside the coil for the pilot fuel control valve or the main fuel control valve. |
| 3479-6 | Aftertreatment #1 Fuel Pressure Control : Current Above Normal | This code can be activated only when the ECM is sending a command to the fuel control valves for the ARD. This code indicates that the current flow through the circuit is excessive. The ARD is disabled. The ECM periodically checks the circuit in order to determine if the high current condition still exists. A short circuit in the wiring between the P2 connector and the coils for the fuel control valves is the only condition that can cause this code. |
| 3482-5 | Aftertreatment #1 Fuel Enable Actuator : Current Below Normal | This code can be activated only when the ECM is not sending a command to the fuel enable valve. This code indicates that the current flow through the circuit is low. The ARD is disabled. The ECM periodically checks the circuit in order to determine if the low current condition still exists. The following conditions can cause this code: There is an open circuit in the wiring. There is an open circuit inside the coil for the fuel enable valve. |
| 3482-6 | Aftertreatment #1 Fuel Enable Actuator : Current Above Normal | This code can be activated only when the ECM is sending a command to the fuel enable valve. This code indicates that the current flow through the circuit is excessive. The ARD is disabled. The ECM periodically checks the circuit in order to determine if the high current condition still exists. The following conditions can cause this code: There is a short circuit in the wiring. There is a short circuit inside the coil for the fuel enable valve. |
| 3487-5 | Aftertreatment #1 Air Pressure Control : Current Below Normal | This code can be activated only when the ECM is not sending a command to the air pressure control valve. This code indicates that the current flow through the circuit is low. The ECM periodically checks the circuit in order to determine if the low current condition still exists. The following conditions can cause this code: There is an open circuit in the wiring. There is an open circuit inside the coil for the air pressure control valve. |
| 3487-6 | Aftertreatment #1 Air Pressure Control : Current Above Normal | This code can be activated only when the ECM is sending a command to the air pressure control valve. This code indicates that the current flow through the circuit is excessive. The ECM periodically checks the circuit in order to determine if the high current condition still exists. The following conditions can cause this code: There is a short circuit in the wiring. There is a short circuit inside the coil for the air pressure control valve. |
| 520194-5 | CGI Actuator Shaft Position : Current Below Normal | This code can be activated only when the ECM is not sending a command to the CGI control group. This code indicates that the current flow through the circuit is low. The ECM periodically checks the circuit in order to determine if the low current condition still exists. The following conditions can cause this code: There is an open circuit in the wiring. There is an open circuit inside the coil for the CGI control group. |
| 520194-6 | CGI Actuator Shaft Position : Current Above Normal | This code can be activated only when the ECM is sending a command to the CGI control group. This code indicates that the current flow through the circuit is excessive. The ECM periodically checks the circuit in order to determine if the high current condition still exists. The following conditions can cause this code: There is a short circuit in the wiring. There is a short circuit inside the coil for the CGI control group. |
| Follow the troubleshooting procedure in order to identify the root cause of the problem. | ||
Component Location
 | |
| Illustration 1 | g01441913 |
Typical left side view Coil (1) is on the fuel filter base. The location of the fuel filter base depends on the engine configuration. (1) Coil for the fuel enable valve (2) Coil for the pilot fuel control valve (3) Coil for the main fuel control valve | |
 | |
| Illustration 2 | g01437650 |
Typical view of the right side of a C13 engine The C15 engine is similar. (4) Coil for the CGI control group (5) Coil for the air pressure control valve | |
 | |
| Illustration 3 | g03816590 |
Schematic diagram for the solenoids | |
Electrical Checkouts on the Cat® Electronic Technician (ET)
The following electrical checkouts are available for troubleshooting the circuits for the coils. Access the overrides by clicking the following menus: "Diagnostics", "Diagnostic Tests" and "System Troubleshooting Settings".
"ARD Fuel Pressure Control Position Override" - This override is only available when the engine speed is zero rpm. This override sends a percentage value of current flow through the circuit for the fuel control valves. This allows the circuit to be checked for an open circuit or for a short circuit. Enter a percentage value of 100 in order for sufficient current to flow through the circuit. Approximately 10 seconds are required in order for a code to occur once the percentage value has been entered.
"ARD Fuel Enable Actuator Override" - This override is only available when the engine speed is zero rpm. This override commands current flow to flow through the circuit for the fuel enable valve. This allows the circuit to be checked for an open circuit or for a short circuit. Approximately 10 seconds are required in order for a code to occur once the percentage value has been entered.
"ARD Air Pressure Control Position Override" - This override is only available when the engine speed is zero rpm. This override sends a percentage value of current flow through the circuit for the air pressure control valve. This allows the circuit to be checked for an open circuit or for a short circuit. Enter a percentage value of 100 in order for sufficient current to flow through the circuit. Approximately 10 seconds are required in order for a code to occur once the percentage value has been entered.
Engine Air System Verification Test - This automated test can be used to check for problems with the current flow through the circuit for the CGI control group. The test is performed while the engine is running. Refer to Troubleshooting, "Air System Verification Test" for additional information on this test.
Test Step 1. Inspect the Wiring and the Electrical Connections
- Verify that the engine is off.
- Locate the coil that relates to the diagnostic code. Check the wiring between the coil and the P2 connector. Visually inspect the electrical components. Look for the following problems:
- Loose connections or damaged connectors
- Moisture on the connectors or the wiring
- Damage that is caused by excessive heat
- Damage that is caused by chafing
- Improper routing of wiring
- Damaged insulation
- Loose connections or damaged connectors
- Perform a 10 lbs pull test on each of the wires at the harness connectors for the coil. This verifies that each wire is crimped to the terminal and that the terminals are fully inserted into the connector.
Expected Result:
There is a problem with the wiring.
Results:
- There is a problem with the wiring. -
Repair: Perform the following procedure:
- Repair the wiring problem. Replace parts, if necessary.
- Clear the logged code.
- Perform an electrical checkout by performing either of the following procedures:
If you are troubleshooting a problem with the circuit for the air pressure control valve or a fuel valve, enter a percentage value of 100 into the appropriate override. Wait for 10 seconds. Look for a diagnostic trouble code to become active. Then, disable the override.
If you are troubleshooting a problem with the circuit for the CGI control group, run the Engine Air System Verification Test. Look for a diagnostic trouble code to become active during Test Point 1. Then, stop the test.
If you are troubleshooting a -5 code and the code became active during the electrical checkout, proceed to Test Step 2. If you are troubleshooting a -6 code and the code became active during the electrical checkout, proceed to Test Step 3. If no codes became active during the electrical checkout and you are troubleshooting a problem with the circuit for the air pressure control valve or the CGI control group, proceed to Test Step 4. If no codes became active during the electrical checkout and you are troubleshooting a problem with the circuit for the fuel system, proceed to Test Step 5.
- The wiring appears to be OK. - If you are troubleshooting a -5 code, proceed to Test Step 2. If you are troubleshooting a -6 code, proceed to Test Step 3.
Test Step 2. Check the Wiring for an Open Circuit
- Connect a jumper wire between the terminals of the harness connector for the solenoid. This replaces the solenoid with a short circuit.
 | |
| Illustration 4 | g01437550 |
Jumper wire and harness connector | |
- Clear the -5 code.
- Perform the appropriate electrical checkout.
Expected Result:
A -5 code became active during the electrical checkout.
Results:
- Yes - A -5 code became active during the electrical checkout. The ECM did not detect the jumper wire. There is an open circuit in the wiring between the coil and the P2 connector. There may be a problem with a connector.
Repair: Perform the following procedure:
- Clear the -5 code.
- Repair the wiring problem. Replace parts, if necessary.
- Perform the appropriate electrical checkout. Verify that no diagnostic codes become active during the electrical checkout.
If you are troubleshooting a problem with the circuit for the air pressure control valve or the CGI control group, proceed to Test Step 4. If you are troubleshooting a problem with the circuit for a fuel valve, proceed to Test Step 5.
- No - A -6 code is activated during the electrical checkout. The ECM detected the jumper wire. The wiring is OK.
Repair: Perform the following procedure:
- Remove the jumper wire from the harness connector.
- Obtain a new coil. Do not install the new coil.
Show/hide table
Illustration 5 g01438018
A coil that is serviced separately
- Connect the new coil to the engine harness.
- Perform the appropriate electrical checkout for the new coil. Verify that no diagnostic codes become active during the electrical checkout.
- Install the new coil.
If you are troubleshooting a problem with the circuit for the air pressure control valve or the CGI control group, proceed to Test Step 4. If you are troubleshooting a problem with the circuit for a fuel valve, proceed to Test Step 5.
Test Step 3. Check the Wiring for a Short Circuit
- Disconnect the coil from the engine harness.
- Clear the -6 code.
- Perform the appropriate electrical checkout.
Expected Result:
A -6 code became active during the electrical checkout.
Results:
- Yes - A -6 code became active during the electrical checkout. The ECM did not detect the open circuit. There is a short circuit in the wiring between the coil and the P2 connector. There may be a problem with a connector.
Repair: Perform the following procedure:
- Clear the -6 code.
- Repair the wiring problem. Replace parts, if necessary.
- Perform the appropriate electrical checkout for the new coil. Verify that no diagnostic codes become active during the electrical checkout.
If you are troubleshooting a problem with the circuit for the air pressure control valve or the CGI control group, proceed to Test Step 4. If you are troubleshooting a problem with the circuit for a fuel valve, proceed to Test Step 5.
- No - A -5 code became active during the electrical checkout. The ECM detected the open circuit. The wiring is OK. The coil has a short circuit.
Repair: Perform the following procedure:
- Replace the coil.
- Clear the -6 code.
- Perform the appropriate electrical checkout for the new coil. Verify that no diagnostic codes become active during the electrical checkout.
If you are troubleshooting a problem with the circuit for the air pressure control valve or the CGI control group, proceed to Test Step 4. If you are troubleshooting a problem with the circuit for a fuel valve, proceed to Test Step 5.
Test Step 4. Perform the Engine Air System Verification Test
Perform the Engine Air System Verification Test. Refer to Troubleshooting, "Air System Verification Test" for additional information on the test, if necessary.
Expected Result:
The results for all of the Test Points are within the acceptable range.
Results:
- The results for all of the Test Points are within the acceptable range. - Proceed to Test Step 5.
- The results for Test Point 1 or Test Point 2 are not within the acceptable range. There is a problem with the CGI system. -
Repair: Refer to Troubleshooting, "Clean Gas Induction - Test".
STOP
- The results for Test Point 3 or Test Point 4 are not within the acceptable range. -
Repair: Refer to Troubleshooting, "ARD Combustion Air - Test".
STOP
Test Step 5. Perform a Stationary Regeneration
- The ECM disables the ARD if a 3715-31 code is active. Perform the following procedure if a 3715-31 is present. If there is no 3715-31 code, proceed to the next step for performing the stationary regeneration.
Use Cat ET in order to view the following status parameters:
Note: Create a new status group in order to view these parameters.
- "Diesel Particulate Trap #1 Differential Pressure"
- "Diesel Particulate Trap #2 Differential Pressure" (if equipped)
- Start the engine and run the engine at 1400 rpm.
- Monitor the differential pressure for 30 seconds.
- Replace any DPF that exceeds15 kPa (2.1 psi) differential pressure.
- Clear the 3715-31 code for any DPF that does not exceed 15 kPa (2.1 psi) differential pressure and proceed to the next step for performing the stationary regeneration.
- "Diesel Particulate Trap #1 Differential Pressure"
- If the following codes are active, clear the codes. The ARD will not light if the codes are active.
- 3703-31 Diesel Particulate Filter Active Regeneration Inhibited Due to Inhibit Switch
- 3530-31 Aftertreatment #1 Regeneration Manually Disabled
- 3703-31 Diesel Particulate Filter Active Regeneration Inhibited Due to Inhibit Switch
- Click the "Disconnect" icon on Cat ET in order to disconnect Cat ET from the engine.
- Turn the keyswitch to the Off position. Wait for 5 seconds.
- Turn the keyswitch to the On position.
- Click the "Connect" icon on Cat ET in order to connect Cat ET to the engine.
- Start the engine. Allow the engine to idle for 3 minutes.
- Start a stationary regeneration by selecting the following menus on Cat ET:
- "Service"
- "Service Procedures"
- "Manual Diesel Particulate Filter Regeneration"
Cat ET will display a "Waiting On Requirements" window. The ECM will automatically elevate the engine speed to 1400 rpm. If the "Waiting On Requirements" window remains displayed for more than 5 minutes, abort the regeneration. Then, select the menu options again in order to start the stationary regeneration.
The duration of the stationary regeneration depends on the soot load in the DPF. The ECM will automatically return the engine speed to low idle after the stationary regeneration is complete.
Note: The ECM tests the nozzles for plugging after the stationary regeneration is complete. Approximately 10 minutes are required in order for the test to provide a result. A 3556-7 code will become active if the nozzles are plugged.
- "Service"
Expected Result:
The stationary regeneration completed successfully.
Results:
- The stationary regeneration completes successfully. - STOP
- The stationary regeneration did not complete successfully. -
Repair: Check the list of active diagnostic codes. Troubleshoot the code that applies to the failed regeneration.
STOP