P0618 Alternative Fuel Control Module KAM Error
OBD-II Trouble Code Technical Description
Alternative Fuel Control Module KAM Error
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 Volkswagen VW, Ford, Nissan, etc.
A stored code P0618 means that the powertrain control module (PCM) has detected a malfunction with the alternative fuel control module (AFCM). The issue has occurred in the keep-alive memory (KAM) portion of the AFCM/PCM.
The P0618 code is limited to vehicles that use alternative fuels such as natural gas and electricity for propulsion.
In some cases, the AFCM and PCM may be separate from one another. More often, they are integrated into a single module. This increases controller efficiency in addition to saving automakers space, time, and money.
KAM allows the PCM and other controllers to retain data even when the ignition is turned off or battery power is interrupted briefly.
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 AFCM/PCM KAM capacity, if a problem is detected, a code P0618 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.
Example photo of a fuel pump control module:
What is the severity of this DTC?
Internal control module codes must always be taken seriously. A stored code P0618 could result in a variety of drivability concerns as valuable controller memory may be lost.
What are some of the symptoms of the code?
Symptoms of a P0618 trouble code may include:
Engine drivability issues Engine stall when idling Delayed engine cranking (especially when cold) Other stored codesWhat are some of the common causes of the code?
Causes for this code may include:
Faulty AFCM/PCM AFCM/PCM programming error Open or shorted circuit or connectors in the CAN harness Failed AFCM/PCM power source Insufficient control module groundWhat are some P0618 troubleshooting steps?
Unfortunately, even the most experienced and well-equipped professional technician may find diagnosing a code P0618 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 AFCM/PCM power supply codes are present, they will need to be repaired before attempting to diagnose a P0618.
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 P0618 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 P0618, information may be your greatest tool. Search your vehicle information source for technical service bulletins (T
Read: 44
