P2156 Fuel Injector Group D Circuit Low

Description and meaning of DTC p2156

This is a generic powertrain diagnostic trouble code (DTC) and typically applies to OBD-II vehicles. That may include but is not limited to vehicles from Dodge Ram (Cummins), GMC Chevrolet (Duramax), VW, Audi, Ford (Powerstroke), Mercedes Sprinter, Peugeot, Alfa Romeo, Nissan, Saab, Mitsubishi, etc. Although generic, the exact repair steps may vary depending on year, make, model and powertrain configuration. Fuel injectors are an integral part of the fuel delivery systems in modern day vehicles. Fuel delivery systems use varying amounts of 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 to the carburetor because injectors are more efficient and effective in controlling fuel delivery. As a result, they have improved our fuel economy, and engineers have been actively designing more ideal ways to increase efficiency to this design. Given the fact that the injector's spray is controlled electronically, supply voltage is crucial in supplying fuel to the cylinders. That said, a problem in this circuit can and/or will cause significant drivability issues among other potential hazards/symptoms. The group letter "D" in this code is used to distinguish what exact circuit the fault is referring to. To determine how this applies to your particular vehicle, you will need to refer to manufacturer specific technical information. Some examples of distinctions with injectors: Bank 1, 2, etc. , paired injectors, individual injectors, etc. The ECM illuminates the MIL (Malfunction Indicator Lamp) with P2156 and/or related codes (P2155, P2157) when it monitors a fault within the supply voltage to the fuel injectors and/or their circuits. The fact that the fuel injectors' harnesses are routed in close proximity to extreme temperatures should be noted. Because of the location of the harnesses, they are volatile to physical damage. With this in mind, I will say, most of the time, this will be a mechanical issue. The P2156 Fuel Injector Group D Circuit Low code is active when the ECM detects a low voltage condition within the supply voltage circuit within the fuel injectors or their circuits.

p2156 diagnostic trouble code symptoms

Symptoms of a P2156 trouble code may include:Erratic engine performanceMisfireFuel economy reducedErratic idleExcessive smokeEngine noise(s)Lack of powerCannot climb steep hillsReduced throttle response

DTC p2156 - possible causes

Causes for this P2156 fuel injector group supply voltage code may include: Defective or damaged fuel injector(s)Damaged wiring harnessInternal wiring malfunctionInternal ECM issueConnector problem

How to fix OBD-II diagnostic trouble code p2156

Basic Step #1First recommended step is to locate which "group" of sensors the manufacturer is referring to. With this information, you can then find the physical location of the injector(s) and their circuits. This may involve removing numerous engine covers and/or components to gain visual access (if possible). Make sure to inspect the harness for frayed wires. Any worn-away insulation should be properly repaired with shrink-tube to prevent further and/or future issues. Basic Step #2At times, water and/or fluids may get "trapped" in the valleys where the injectors are installed. This increases the odds of the sensor's connectors, among other electrical connections, to corrode at a faster than normal rate. Make sure everything is how it should be and the connectors tabs are properly sealing the connection. Don't hesitate using some electrical contact cleaner to make everything connect and disconnect smoothly, not to mention the increased electrical connectivity within the connections with the use of this product. Basic Step #3Verify the integrity of the circuit by following troubleshooting steps provided by your specific vehicle's service manual. One example is to disconnect the supply voltage circuit from the ECM and at the fuel injector, then using your multimeter, determine whether or not the wires are in good working order. One test I like to do to determine quickly if there is an open within a particular wire which would help with code P2156 is to do a "continuity test". Setting your multimeter to RESISTANCE (a. k. a. : ohm, impedance, etc. ), touch one end to one tip of the circuit and the other end at the other tip. Any higher then desired value may indicate a problem within the circuit. Any issue here will need to be determined by tracing the particular wire you are diagnosing.

More OBD-II diagnostic trouble codes (DTC)