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P0818 is a diagnostic trouble code (DTC) for "Driveline Disconnect Switch Input Circuit". This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. Our certified mobile mechanics can come to your home or office to perform the Check Engine Light diagnostic for $114.99 . Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.0 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.
A P0818 trouble code is related to a four wheel drive vehicle’s transfer case and its neutral position switch (driveline disconnect).
P0818 is an OBD-II generic code for a voltage problem with a four wheel drive vehicle’s transfer case neutral position switch. If the engine computer detects a signal from the switch indicating the transfer case is in neutral when the vehicle is in high range or moving, it will indicate a problem with the switch itself, causing a P0818.
The most common causes for a P0818 are:
Because a P0818 indicates the transfer case is in neutral when it in fact is not, there should be no noticeable symptoms other than a check engine light. If you encounter this code, it’s wise to ensure your transfer case will shift from high range, neutral, and low range.
It’s likely your mechanic will first clear the code, reset the engine computer, ensure the transfer case is in a normal position, and test drive to ensure the P0818 comes back. If it does, they will then move on to the switch connector and wiring harness, testing both for proper resistance. If either do not meet the manufacturer’s specifications, they should be replaced. If they do however, there could be an issue with the neutral position switch itself. This should be tested for resistance and replaced as necessary.
While rare, a bad ground or connector between the engine computer and the transfer case wiring harness could cause a P0818, but this won’t be investigated until it’s confirmed both the neutral position switch and wiring harness are in good condition.
Driver error may cause a P0818 to become a stored code, so it’s wise to first clear the code, reset the ECU, and test drive the vehicle before parts are replaced.
A P0818 by itself shouldn’t cause any mechanical or driveability issues. However, if it is accompanied by other codes, there could be an issue with the transfer case wiring.
The most common repairs for a P0818 are as follows:
While rare, replacing the engine computer may be a needed repair as well.
P0818 codes are common in Toyota SUVs and 4x4s - especially FJ Cruisers and Lexus LX/GX models.
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