System Operation Description:
The Engine Control Module (ECM) monitors the current flow through the coils of the applicable components
The ECM sets a diagnostic trouble code if the current flow through a coil is incorrect. These codes can be activated only when the ECM is sending a command to the control valves. A -5 code indicates that the current flow through the circuit is low and there is an open in the circuit. A -6 code indicates that the current flow through the circuit is high and there is a short in the circuit.
Table 1 lists the diagnostic codes for incorrect current flow.
Note: Some of the following codes may not be applicable for certain applications.
| Diagnostic Trouble Codes | |||
|---|---|---|---|
| CDL Code | J1939 Code | Code Description | Comments |
| 444-5 | 677-5 | Engine Starter Motor Relay : Current Below Normal | This code indicates there is a problem with the engine starter motor relay and/or the electrical circuit on the ECM. |
| 444-6 | 677-6 | Engine Starter Motor Relay : Current Above Normal | This code indicates there is a problem with the engine starter motor relay and/or the electrical circuit on the ECM. |
| 1922-5 | 2949-5 | Engine Intake Valve Actuation System Oil Pressure Control Valve : Current Below Normal | This code indicates that there is a problem with the Engine Intake Valve Actuation System Oil Pressure Control Valve circuit or solenoid. |
| 1922-6 | 2949-6 | Engine Intake Valve Actuation System Oil Pressure Control Valve : Current Above Normal | This code indicates that there is a problem with the Engine Intake Valve Actuation System Oil Pressure Control Valve circuit or solenoid. |
| 2232-5 | 1074-5 | Engine Retarder Solenoid : Current Below Normal | This code indicates there is a problem with the engine retarder solenoid and/or electrical circuit on the ECM. |
| 2232-6 | 1074-6 | Engine Retarder Solenoid : Current Above Normal | This code indicates there is a problem with the engine retarder solenoid and/or electrical circuit on the ECM. |
| 2461-5 | 3479-5 | ARD Fuel Pressure #1 Control : Current Below Normal | This code indicates there is a problem with the pilot fuel solenoid and/or electrical circuit on the CEM. |
| 2461-6 | 3479-6 | ARD Fuel Pressure #1 Control : Current Above Normal | This code indicates there is a problem with the pilot fuel solenoid and/or electrical circuit on the CEM. |
| 3182-5 | 4301-5 | Aftertreatment #1 Fuel Injector #1 Heater : Current Below Normal | There is low current flow between the ECM and the relay for the heating element. The most likely cause of this code is an open circuit in the wiring between the ECM and the relay. There may be a problem with a connector. |
| 3182-6 | 4301-6 | Aftertreatment #1 Fuel Injector #1 Heater : Current Above Normal | There is excessive current flow between the ECM and the relay for the heating element. If the high current continues for 10 seconds, the ECM disables the output for the heating element. The power to the ECM must be cycled in order to reset the fault detection circuit. The most likely cause of this code is a short circuit in the wiring between the ECM and the relay. There may be a problem with a connector. |
| 3391-5 | 5425-5 | ARD Fuel Pressure #2 Control Actuator : Current Below Normal | This code indicates there is a problem with the main fuel solenoid and/or electrical circuit on the CEM. |
| 3391-6 | 5425-6 | ARD Fuel Pressure #2 Control Actuator : Current Above Normal | This code indicates there is a problem with the main fuel solenoid and/or electrical circuit on the CEM. |
| 3405-5 | 2791-5 | EGR Valve Control : Current Below Normal | This code indicates there is an electrical problem with the solenoid valve and/or circuit on the NRS valve actuator |
| 3405-6 | 2791-6 | EGR Valve Control : Current Above Normal | This code indicates there is an electrical problem with the solenoid valve and/or circuit on the NRS valve actuator. |
| 3409-5 | 5276-5 | Engine Exhaust Manifold Bank #1 Flow Balance Valve Solenoid : Current Below Normal | This code indicates there is a problem with the exhaust balance valve solenoid and/or electrical circuit. |
| 3409-6 | 5276-6 | Engine Exhaust Manifold Bank #1 Flow Balance Valve Solenoid : Current Above Normal | This code indicates there is a problem with the exhaust balance valve solenoid and/or electrical circuit. |
| 3413-5 | 5424-5 | ARD Fuel Flow Diverter Actuator : Current Below Normal | This code indicates there is a problem with the solenoid on the diverter valve and/or the electrical circuit located on the ARD electric fuel pump. |
| 3413-6 | 5424-6 | ARD Fuel Flow Diverter Actuator : Current Above Normal | This code indicates there is a problem with the solenoid on the diverter valve and/or the electrical circuit located on the ARD electric fuel pump. |
| 3427-5 | 5423-5 | Aftertreatment Fuel Pump Relay : Current Below Normal | This code indicates there is problem with the relay and/or circuit for the ARD electric fuel pump. |
| 3427-6 | 5423-6 | Aftertreatment Fuel Pump Relay : Current Above Normal | Indicates there is problem with the relay and/or circuit for the ARD electric fuel pump. |
| Follow the troubleshooting procedure in order to identify the root cause of the problem. | |||
Note: Refer to Troubleshooting, “Component Location” in this manual for the proper location of the components listed in this procedure.
Electrical Checkouts on the Caterpillar Electronic Technician (ET)
| Component | Electrical Checkout |
| Engine retarder solenoid | Engine Retarder Solenoid Override – initiate an engine retarder solenoid override through Cat ET in order to activate the engine retarder solenoid. Review active diagnostic codes to determine what code is present. |
| Engine Intake Valve Actuation System Oil Pressure Control Valve | Start the engine. Use the “Intake Valve Actuation System Test” in diagnostic tests in Cat ET to activate the Engine Intake Valve Actuation System Oil Pressure Control Valve. Once the test is complete, review the active diagnostic codes to determine the code that is present. |
| Pilot control solenoid | ARD ignition test – initiate an ARD ignition test through Cat ET in order to activate the pilot control valve solenoid. If the fault becomes active, the test will abort. Review active diagnostic codes to determine what code is present. |
| Main control solenoid | ARD ignition test – initiate an ARD ignition test through Cat ET in order to activate the main control valve solenoid. If the fault becomes active, the test will abort. Review active diagnostic codes to determine what code is present. |
| Solenoid valve for NRS valve actuator | EGR system test – initiate the EGR system test through Cat ET in order to activate the control solenoid for the NRS valve. If the fault becomes active, the test will abort. Review active diagnostic codes to determine what code is present. |
| Exhaust balance valve solenoid | Use the “Engine exhaust manifold bank #1 flow balance valve solenoid override” in the override parameters section in Cat ET to activate the exhaust balance valve solenoid. Review active diagnostic codes to determine what code is present. |
| Fuel diverter valve | Use the “ARD fuel flow diverter actuator override” in the override parameters section in Cat ET to activate the fuel diverter valve on the ARD fuel pump. Review active diagnostic codes to determine what code is present. |
| Relay for ARD fuel pump | Use the “Aftertreatment fuel pump relay override” in the override parameters section in Cat ET to activate the ARD fuel pump. Review active diagnostic codes to determine what code is present. |
| Relay for ARD heater | ARD Nozzle heater circuit test – Initiate the ARD Nozzle heater circuit test through Cat ET in order to activate the ARD heater relay. Review active diagnostic codes to determine if a code is present. |
| Engine Starter Motor Relay | Attempt to start the engine. Once the ECM attempts to energize the relay, the code will become active. Refer to the machine-specific schematic for the “Engine Starter Motor Relay” wiring circuit. |
Illustration 1 g03646099
Refer to the machine-specific schematic for the “Engine Starter Motor Relay” wiring circuit.
Not all connectors are shown, refer to the appropriate schematic
| Troubleshooting Test Steps | Values | Results |
|---|---|---|
|
1. Determine the Diagnostic Code
A. Establish communication between Caterpillar Electronic Technician (ET) and the Electronic Control Module (ECM) . Refer to Troubleshooting, “Electronic Service Tools”, if necessary. B. Download the “Warranty Report” from the engine ECM before performing any troubleshooting or clearing diagnostic trouble codes. C. Wait at least 30 seconds in order for the diagnostic codes to become active. Look for an active -5 code or for a logged -6 code. |
Diagnostic Trouble Codes |
Result: There is an active or there is a logged -5 code.
Proceed to Test Step 2. Result: There is an active or there is a logged -6 code. Proceed to Test Step 3. |
|
2. Check the Wiring for an Open Circuit
A. Verify that the harness connector is free of debris, free of corrosion and securely connected. B. Disconnect the solenoid from the engine harness. C. Connect a jumper wire between the terminals of the harness connector for the suspect coil. The coil is replaced with a short circuit. D. Perform the appropriate electrical checkout. Refer to Table 2. |
Open circuit |
Result: 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 ECM connector. There may be a problem with a connector. Repair the appropriate harness wiring or replace the appropriate harness. Verify that the problem is resolved. Result: A -6 code is activated during the electrical checkout. The ECM detected the jumper wire. There is a problem with the solenoid. Clear the -6 code by cycling the keyswitch to the Off position. Replace the solenoid. Verify that the problem is resolved. |
|
3. Check the Wiring for a Short Circuit
A. Disconnect the solenoid from the engine harness. B. Clear the -6 code by cycling the keyswitch to the Off position. C. Perform the appropriate electrical checkout. Refer to Table 2. |
Short Circuit |
Result: 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 ECM connector. There may be a problem with a connector. Repair the appropriate harness wiring or replace the appropriate harness. Verify that the problem is resolved. Result: 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. Replace the solenoid. Verify that the problem is resolved. |
Test Step 1.
Complete the procedure in the order in which the steps are listed.
Results:
- The procedure corrected the issue. – STOP
- The procedure did not correct the issue. –Repair: Contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).
STOP