P0612 Fuel Injector Control Module Relay Control
OBD-II Trouble Code Technical Description
Fuel Injector Control Module Relay Control
What does that mean?
This generic powertrain diagnostic trouble code (DTC) typically applies to many OBD-II vehicles. That may include but is not limited to vehicles from Chevrolet, GMC, Dodge, Ram, etc.
A stored code P0612 means that the powertrain control module (PCM) has detected an internal control module malfunction. The issue is related to the portion of the PCM that controls the fuel injector control module relay.
In some cases, the fuel injector controller may be separate from the PCM. Most frequently, it is integrated into the PCM. This saves automakers space, time, and money.
Likewise, the fuel injector control module relay may be an integral part of the PCM or it may be a conventional relay that is located away from the PCM. Consult a reliable source of vehicle information to determine the location of the fuel injector control relay for the vehicle in question.
Each time the ignition is turned on and the PCM is energized, multiple controller self-tests are performed. In addition to running internal controller self-tests, the controller area network (CAN) is used to compare signals from each individual module to ensure that the various controllers are interacting properly.
In monitoring fuel injector relay control function, if the PCM detects a problem, a code P0612 will be stored and a malfunction indicator lamp (MIL) may be illuminated. Depending upon the perceived severity of the malfunction, multiple failure cycles may be necessary for MIL illumination.
A fuel pump control module:
What is the severity of this DTC?
Internal control module codes must always be taken seriously. A stored code P0612 could result in a variety of drivability concerns, including a no-start condition.
What are some of the symptoms of the code?
Symptoms of a P0612 trouble code may include:
Engine drivability issues Reduced engine performance Diminished fuel efficiency Other stored codesWhat are some of the common causes of the code?
Causes for this code may include:
Faulty PCM PCM programming error Defective PCM power supply relay Open or shorted circuit or connectors in the CAN harness Failed PCM power source Insufficient control module groundWhat are some P0612 troubleshooting steps?
Unfortunately, even the most experienced and well-equipped professional technician may find diagnosing a code P0612 to be quite a challenge. There is also the issue of reprogramming. Without the necessary reprogramming equipment, it will be impossible to replace a defective controller and complete a successful repair.
If ECM/PCM power supply codes are present, they will need to be repaired before attempting to diagnose a P0612.
There are several preliminary tests that can be performed prior to declaring any controller defective. A diagnostic scanner, a digital volt/ohmmeter (DVOM), and a source of reliable vehicle information will be required.
Connect the scanner to the vehicle diagnostic port and retrieve all stored codes and freeze frame data. You will want to write this information down, just in case the code proves to be an intermittent one. After recording all pertinent information, clear the codes and test drive the vehicle until the code is reset or the PCM enters readiness mode. If the PCM enters readiness mode, the code is intermittent and will be more difficult to diagnose. The condition, which caused the P0612 to be stored, may even need to worsen before a diagnosis can be made. If the code is reset, continue with this short list of preliminary tests.
When attempting to diagnose a P0612, information may be your greatest tool. Search your vehicle information source for technical service bulletins (TSB) that parallel
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