P0618 code definition
The P0618 trouble code detects an error that has occurred with the alternative fuel control module keep alive memory.
What the P0618 code means
The P0618 trouble code is a standard OBD-II trouble code that notes an issue with the alternative fuel control module keep alive memory. When the alternative fuel control module keep alive memory fails, or has a fault, it will be detected by either the powertrain control module (PCM), or one of the many other control modules (such as the antilock brake control module, instrument panel control module, traction control module, and cruise control module. When the PCM or any of the other control modules detects this keep alive memory error, the P0618 trouble code will be detected.
What causes the P0618 code?
Potential causes of the P0618 trouble code include:
- Malfunctioning alternative fuel control module
- Shorted or open wires in the controller area network (CAN)
- Loose, corroded, or damaged connectors in the CAN bus harness
- A loose or damaged ground strap or ground wire in the control module
- Malfunctioning CAN bus
What are the symptoms of the P0618 code?
When the P0618 trouble code is detected, the check engine soon Warning Light will usually illuminate on the vehicle’s instrument cluster. The vehicle can also experience a number of performance problems, such as difficulty idling, constant stalling, slow acceleration, harsh shifting, and lowered fuel efficiency.
How does a mechanic diagnose the P0618 code?
The P0618 code will be diagnosed using a standard OBD-II trouble code scanner. A trained and trustworthy technician will analyze the freeze frame data to assess the code and check for any other trouble codes that may be present. The codes should then be reset, and the vehicle should be restarted, to see if the codes persist. If the code no longer exists, it is likely an intermittent issue, or an erroneously triggered code.
If the P0618 trouble code returns, the mechanic should visually inspect the electrical components of the alternative fuel control module and the CAN bus. All of the wires, connectors, and fuses should be checked for damage, and replaced as necessary. Then, the mechanic can check the ground wires and straps for continuity with the battery.
Next, the mechanic can use a CAN scanner to diagnose the alternative fuel control module, and see if the entire module needs replacing.
Whenever any component is replaced, the mechanic should reset the codes and restart the vehicle before continuing with inspections and repairs. This makes sure that the technician is able to know as soon as the issue has been resolved.
Common mistakes when diagnosing the P0618 code
The most common error that is made in diagnosing the P0618 code comes from failing to properly adhere to the OBD-II trouble code diagnosis protocol. The protocol should always be followed in order, to ensure that the issue is resolved in the most efficient manner possible.
The P0618 code can result in other codes appearing, and addressing those codes without addressing the P0618 code can lead to a repair that never actually fixes the fundamental problem.
How serious is the P0618 code?
The P0618 code usually won’t keep a car from being able to drive, but it often causes a number of drivability issues, including constant stalling and harsh shifting. Not only is this a hassle, but it can lead to further issues and severe damage, so thee P0618 code should be tackled as soon as possible.
What repairs can fix the P0618 code?
Some repairs for the P0618 trouble code are:
- Replacement of the alternative fuel control module
- Replacement of the wires, connectors, and fuses in the module
- Replacement of ground straps and ground wires
- Replacement of wires and connectors in the CAN bus
- In rare cases, replacement of the CAN bus
Additional comments for consideration regarding the P0618 code
It is very common for the P0618 to trigger other trouble codes, such as transmission, fuel injector, and engine misfire codes. Nearly every trouble code that deals with issues of drivability can be caused by this specific code. As such, mechanics should always address trouble codes in the order that they appear in freeze frame data, to be sure that the root of the problem is actually being addressed.
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