Technical Description of OBD-II Trouble Code
The circuit for Fuel Injector Group D is open or malfunctioning.
What does that mean?
This is a generic diagnostic trouble code (DTC) for the powertrain and is commonly found in OBD-II vehicles. This code can apply to various vehicle makes and models including Dodge Ram (Cummins), GMC Chevrolet (Duramax), VW, Audi, Ford (Powerstroke), Mercedes Sprinter, Peugeot, Alfa Romeo, Nissan, Saab, Mitsubishi, etc. The specific repair steps may vary depending on the year, make, model, and powertrain configuration.
Fuel injectors play a crucial role in the fuel delivery systems of modern vehicles.
Fuel delivery systems use different components to control and monitor the volume, timing, pressures, etc. of the system in conjunction with the ECM (Engine Control Module). Fuel injectors were introduced as a replacement for carburetors because they are more efficient and effective in controlling fuel delivery. As a result, they have improved fuel economy, and engineers continue to design more efficient ways to enhance this design.
Since the injector’s spray is electronically controlled, the supply voltage is essential for delivering fuel to the cylinders. Therefore, a problem in this circuit can cause significant drivability issues and other potential hazards/symptoms.
The group letter “D” in this code is used to identify the specific circuit that the fault refers to. To understand how this applies to your vehicle, you will need to consult manufacturer-specific technical information. Examples of distinctions with injectors include Bank 1, 2, etc., paired injectors, individual injectors, etc.
The ECM triggers the MIL (Malfunction Indicator Lamp) and displays the codes P2155 and/or related codes (P2156, P2157) when it detects a fault in the supply voltage to the fuel injectors and/or their circuits. It is important to note that the fuel injector harnesses are located in close proximity to extreme temperatures, making them susceptible to physical damage. Therefore, in most cases, this issue is mechanical in nature.
The P2155 Fuel Injector Group D Circuit/Open code is active when the ECM detects an open or malfunction in the fuel injector’s supply voltage circuit.
What is the severity of this DTC?
This DTC is considered quite severe. In the field, a lack of fuel in the mixture being burnt is referred to as a “lean” condition. Running the engine lean poses a risk of causing severe engine damage in the short and long term. Therefore, it is crucial to maintain your engine regularly. Diligence is required to ensure smooth and efficient engine operation since it is responsible for transporting us daily.
What are some of the symptoms of the code?
Symptoms of a P2155 trouble code may include:
What are some of the common causes of the code?
Possible causes for the P2155 fuel injector group supply voltage code include:
What are some P2155 troubleshooting steps?
Basic Step #1
The first recommended step is to determine the specific “group” of sensors referred to by the manufacturer. With this information, you can locate the physical location of the injector(s) and their circuits. This may involve removing engine covers and/or components to gain visual access if possible. Inspect the harness for any broken wires and repair any worn-away insulation using shrink-tube to prevent further issues.
Basic Step #2
At times, water and/or fluids may accumulate in the valleys where the injectors are installed. This increases the likelihood of corrosion in the sensor’s connectors and other electrical connections. Ensure that everything is in proper condition and that the connector tabs are sealing the connection correctly. You can use electrical contact cleaner to improve the electrical connectivity within the connections and ensure smooth connection and disconnection.
Basic Step #3
Verify the integrity of the circuit by following the troubleshooting steps provided in your specific vehicle’s service manual. For example, you can disconnect the supply voltage circuit from the ECM and the fuel injector, and then use a multimeter to check if the wires are functioning properly.
One quick test to determine if there is an open within a particular wire, which can help with code P2155, is to perform a “continuity test”. Set your multimeter to RESISTANCE (ohm, impedance, etc.), touch one end to one tip of the circuit and the other end to the other tip. If the resistance value is higher than desired, it may indicate a problem within the circuit. Any issues here will need to be resolved by tracing the specific wire being diagnosed.
