How severe is this DTC?
I would say rather severe. In the field, we refer to a lack of fuel in the burned mixture as a “lean” condition. When your engine is idling, you risk causing extreme damage to the engine in the short and long term. With this in mind, always follow your engine maintenance. There needs to be some diligence here, so let’s keep our engines running smoothly and efficiently. After all, they pull our weight to get us around every day.
What are some of the symptoms of the code?
Symptoms of a P2151 trouble code may include:
- Irregular engine performance
- Misfire
- Reduced fuel economy
- Irregular idle
- Excessive smoke
- Engine noise(s)
- Lack of power
- Unable to climb steep hills
- Reduced throttle response
What are some common causes of the code?
Causes
of this P2151 fuel injector group supply voltage code may include:
- Faulty or damaged fuel injector(s)
- Damaged wiring harness
- Internal wiring malfunction
- Internal ECM problem
- Connector issue
What are the troubleshooting steps for P2151?
Basic Step #1
The first recommended step is to locate the “group” of sensors that the manufacturer refers to. With this information, you can then find the physical location of the injector(s) and their circuits. This may involve removing many covers and/or engine components to visually access (if possible). Be sure to inspect the harness for short circuits to other power wires. Any worn insulation should be properly repaired with a shrink tube to avoid further and/or future issues.
Basic Step #2
Sometimes water and/or fluids can get “trapped” in the valleys where the injectors are installed. This increases the chances of the sensor connectors, among other electrical connections, corroding at a faster rate than normal. Make sure everything is as expected and that the connector tabs seal the connection properly. Feel free to use an electrical contact cleaner to ensure everything connects and disconnects smoothly, not to mention the increased electrical connectivity in the connections with the use of this product.
Basic Step #3
Check the circuit integrity by following the troubleshooting steps provided by your specific vehicle’s service manual. An example is to disconnect the supply voltage circuit from the ECM and the fuel injector, then using your multimeter, determine whether the wires are in good working order or not.
A test I like to do to quickly determine if there is an open in a particular wire that would help with the P2151 code is to perform a “continuity test.” Set your multimeter to RESISTANCE (aka ohm, impedance, etc.), touch one end to one end of the circuit and the other end to the other end. Any value higher than desired may indicate a problem in the circuit. Any issue here will need to be determined by tracing the particular wire you are diagnosing.