Turbochargers are paired with diesel engines to improve their fuel efficiency and boost their power output. However, with several moving parts within a diesel turbocharger, there is always a chance that something within the turbo can malfunction or become damaged. When this happens, the engine may lose power and efficiency. It is important to be able to recognize when there is an issue with a turbocharger and diagnose the problem so it can be repaired without causing additional damage.

The performance of a turbocharger can only be impacted by mechanical damage or blockage caused by debris. The most common symptoms of a malfunctioning turbocharger include overheating, loss of power, high fuel consumption, excess smoke, high exhaust temperature, and oil leaks.

There are multiple potential causes for each of these issues. It is important to accurately diagnose the issue so the proper action can be taken to fix it. In many instances where there is an issue with the turbocharger, it will display a fault code that indicates the problem, and the part affected.

In this guide, we will discuss some common turbocharger and actuator fault codes, including their causes and effects, and what actions can be taken to address the issue. It is important to remember that the following is a general explanation of possible causes and effects. It is recommended to consult a technician who can accurately diagnose and repair issues for your specific turbocharger and vehicle make and model.

 

Fault Code: SPN 641 FMI 9

Cummins Code: 2636  VGT Actuator Driver Circuit – Abnormal Update Rate

 

SPN 641 FMI 9 is a communicational fault code indicating that the VGT actuator is not communicating with the engine control module (ECM) on the J1939 data link at a normal rate. The specific issue when this fault code is displayed is that there is an abnormal update rate, preventing the data on the CAN bus from being sent and received in a timely manner. The disruption of timely communication makes it difficult for the ECM to properly control the turbocharger’s geometry.

Effects

• Reduced engine power
• Poor fuel efficiency
• Potential engine damage if the issue is ignored
• Smoke from the exhaust

Possible Causes of SPN 641 FMI 9 Fault Code

Power Supply Issue

One potential cause for this fault code is a power supply issue that is preventing the VGT actuator from receiving enough power from the ECM. This could be caused by an open circuit in the power supply wire, insufficient voltage from the ECM, or damaged or disconnected wiring between the ECM and VGT actuator.

You can check the wiring harness that connects the VGT actuator to the ECM for loose connections or damage to the wires. Replacing faulty wires is a possible solution for this issue.

Electrical Circuit Issue

This fault code could be caused by an electrical circuit problem, such as an open circuit in the VGT actuator’s return circuit or an open or short circuit in the J1939 data link between the ECM and VGT actuator. A mechanic can use special tools to check for open and short circuits.

Communication Errors

A communication error over the J1939 data link between the VGT actuator and ECM can cause disruptions in the data transfer. One possible solution for this is to look for and install software updates for the ECM. Issues with the CAN bus network such as interference could also disrupt communication.

Hardware Damage

Damage to the hardware, such as a damaged termination resistor in the engine link data harness, could be causing this fault code. A mechanic can inspect the hardware for damage that may be causing the issue.

Actuator Functionality

It is also possible that the VGT actuator is not functioning properly or responding to commands. Repairing or replacing the VGT actuator could resolve this issue.

Additional Things to Consider

False fault codes do happen and one thing that can trigger false codes is rapid key switch cycling, or frequent cycling of the ignition key. If you think you might have a false fault code, clear the code and see if it comes back.

If you are unsure of what is causing the fault code, having a thorough diagnostic check of the voltage and resistance measurements and data communication link can help identify the specific cause of the fault.

Fault Code: SPN 641 FMI 12

Cummins Code: 1897 VGT Actuator Controller – Bad Intelligent Device or Component

SPN 641 FMI 12 is a fault code that indicates an internal error detected with the smart VGT actuator. The errors include an issue with the VGT actuator position sensor that monitors the position of VGT vanes as well as a communication error preventing the ECM from receiving or properly reading data from the actuator. These errors can result in the actuator ceasing control of the turbocharger.

Effects

The effects of this fault code may include the following:

• Reduced engine power: The inability of the VGT actuator to adjust the turbocharger’s boost prevents the engine from producing full power.
• Poor fuel economy: Inefficient operation of the turbocharger causes higher fuel consumption.
• Rough engine operation: Inconsistent boost pressure can cause rough idling.
• Check engine light: The check engine light typically turns on when there is a problem with the VGT actuator.

Common Causes of SPN 641 FMI 12 Fault Code

• Removal and reinstallation: This fault code can be triggered if the VGT actuator is removed for any reason and the ignition is turned on.
• Failed installation or calibration: If the VGT actuator is not properly installed or calibrated, it could trigger this fault code.
• Damage or malfunction: This fault code will be triggered if the VGT actuator malfunctions or becomes damaged.

Resolving Fault Code SPN 641 FMI 12

• Check for loose connections: Check for loose or damaged connections with the wiring harness attached to the VGT actuator.
• Disconnect and reconnect VGT actuator: Disconnect the VGT actuator from the engine harness while the ignition is on. Reconnect the actuator to the harness.
• Reinstall the VGT actuator: Make sure to follow the installation procedure for the specific VGT actuator.
• Replacement: Replace the VGT actuator if you determine it to be damaged or faulty.
• Software update: Look for and install updates for the ECM which could resolve the communication issue.
• Consult a technician: A technician can diagnose the exact cause of the fault code.

Once the VGT actuator resumes normal operations, the fault code will become inactive.

Fault Code: SPN 641 FMI 13

Cummins Code: 2449 VGT Actuator Controller – Out of Calibration

SPN 641 FMI 13 is a fault code that indicates a problem with the VGT actuator. The possible errors indicated by this fault code include a low voltage signal from the VGT actuator, the VGT actuator being out of calibration, or the VGT actuator not responding properly to commands due to a mechanical issue. The issues associated with this fault code are typically caused by incorrect installation or misalignment between the gear of the VGT actuator and turbocharger housing.

Effects

• Reduced engine power: Engine power can decrease as the VGT actuator has limited ability to adjust the vanes and turbine blade angles.
• Poor acceleration: The reduced engine power will result in difficulty accelerating.
• Rough engine operation: The engine may run and idle roughly.
• Check engine light: This fault code typically triggers the check engine light.
• Damage to the turbocharger: A malfunctioning VGT actuator can cause further damage to the turbocharger if it is not addressed.

Common Causes of SPN 641 FMI 13 Fault Code

• Faulty VGT actuator: The most common cause for this fault code is damage or wear and tear to the VGT actuator, including mechanical or internal electrical issues.
• Sensor issues: The VGT actuator may have a faulty sensor that sends incorrect information.
• Improper installation: Incorrect installation can result in misalignment between the gear of the actuator and turbocharger housing.
• Damaged wiring: The low voltage signal from the VGT actuator could be caused by damaged or faulty wiring that connects the actuator to the wiring harness.

Resolving Fault Code SPN 641 FMI 13

• Check wiring connections: Look for damaged or disconnected wiring from the wiring harness to the VGT actuator. Replace or reconnect the wiring.
• Reinstall the VGT actuator: If the VGT actuator was not installed correctly, it should be removed and reinstalled while strictly following the installation procedure specific to the actuator.
• Replace the VGT actuator: If the VGT actuator is damaged or faulty, it should be replaced with a new actuator.
• Check for software updates: Installing the latest updates for the ECM software could cause the VGT actuator to start responding properly to commands.
• Consult a technician: A qualified technician can run specialized diagnostics to identify the issue and make adjustments to the VGT actuator.

Fault Code: 6713 FMI 9

Cummins Code: 5177 Variable Geometry Turbocharger Actuator Software – Abnormal Update Rate

 

A 6713 FMI 9 fault code indicates that the ECM is not sending or receiving data from the CAN bus at the normal or expected rate. The data received is still valid but falls outside of the normal operating range. This is typically caused by issues with the VGT actuator or the Exhaust Gas Recirculation (EGR) system, specifically the EGR valve that allows a portion of the exhaust gas back into the engine’s combustion chambers.

If this fault code is shown due to the VGT actuator, this is likely because the ECM did not receive the necessary identification message from the actuator which often occurs during the initialization process. In this case, the VGT actuator may need to be reinstalled and/or recalibrated. If the fault code is due to the EGR system, components of this system may need to cleaned, repaired, or replaced.

Effects

• Reduced engine power: The engine will have reduced power output as issues with the EGR system will result in less efficient combustion. Problems with the VGT actuator can also reduce the efficiency of the engine.
• Increased emissions: Issues with the EGR system will increase the level of pollutants in the emissions.
• Rough idling: Inconsistent combustion caused by malfunctioning EGR system can cause rough engine idling.
• Check engine light: Problems with either the EGR system or VGT actuator can cause the check engine light to turn on.

Common Causes of the 6713 FMI 9 Fault Code

• Improper installation or calibration of the VGT actuator: If the VGT actuator is not properly installed or calibrated, it may have a difficult time connecting to the ECM.
• Faulty VGT actuator: Damage or mechanical issues with the VGT actuator may trigger this fault code.
• Fault VGT sensor: A faulty sensor within the VGT actuator may disrupt the data transfer.
• Damaged wiring: Damaged or disconnected wiring that connects the VGT actuator to the wiring harness could cause a disruption in the communication between the actuator and the ECM.
• Dirty or faulty EGR valve: If the EGR valve is dirty or damaged, it could trigger this fault code.
• EGR system leaks: Leaks in the EGR system are another issue that can trigger this fault code.

Resolving 6713 FMI 9 Fault Code

• Check wiring connections: Look for faulty or disconnect wiring between the wiring harness and VGT actuator and replace or reconnect the wiring.
• Reinstall the VGT actuator: Make sure the VGT actuator is reinstalled while strictly adhering to the specific installation procedure so the ECM can receive the necessary identification message.
• Replace the VGT actuator: The VGT actuator must be replaced if it is damaged or faulty.
• Check for software updates: Updating the software for the ECM may resolve the connection issue and allow the ECM to receive the identification message for initialization.
• Repair EGR system components: The components of the EGR system, including the EGR valve, EGR cooler, and EGR actuator may need to be cleaned or replaced. The system should also be checked for leaks.
• Consult a technician: A technician can run diagnostics on the VGT actuator and EGR system to pinpoint the exact cause of the fault code and determine the best course of action.

If you are having an issue with your turbocharger or turbo actuator, HD Turbo can help. Our turbo experts can run diagnostics to identify and address the issue and restore the performance of your turbocharger.