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P0850 is a diagnostic trouble code (DTC) for "Park / Neutral 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. Once we are able to diagnose the problem, you will be provided with an upfront quote for the recommended fix and receive $20.00 off as a credit towards the repair. All our repairs are backed by our 12-month / 12,000-mile warranty.
If the PCM has stored the P0850 code, it means that the input circuit which measures the function of the park/neutral switch has given an abnormal voltage reading.
If the vehicle is put into park or neutral, voltage readings are sent to the PCM from a variety of sensors and components. This data helps the PCM ensure that park or neutral was achieved, and that the vehicle is operating correctly. If the voltage reading from the input circuit on the park/neutral switch does not match the manufacturer’s specifications, the PCM will store the P0850 code. This code is only applicable in vehicles with both an automatic transmission, and four-wheel-drive capability.
In the majority of instances, the P0850 code is caused by a misadjusted transfer case range sensor. This could have been improperly installed during a previous repair.
Other causes may include:
In addition to the illumination of the Check Engine lamp, vehicle owners may observe symptoms such as the inability to engage the four-wheel-drive, harsh shifting or complete failure to shift, and a decrease in fuel efficiency.
The first step is to verify the code with an OBD-II scanner. Once this step has been completed, the mechanic should begin with a visual inspection of all electrical components, including wiring and connectors. Repair or replace any parts as necessary, and then clear the code from the PCM and retest the system. If the code reappears, the next step is to check the battery voltage and ground signals at the park/neutral switch.
Throughout the diagnostic process, the mechanic should compare readings to the manufacturer’s specifications. If the readings are within the acceptable range, then suspect the sensor itself is bad; if the readings are not within the acceptable range, then other repairs will have to be attempted. Always remember to clear the code and retest the system after each potential repair, to ensure that the correct repair is pinpointed and time is not wasted on further repairs.
The most common misdiagnosis is to blame a faulty transfer case range sensor, when in fact the part was not faulty, but simply misadjusted.
Because this code directly relates to the vehicle’s drivability, it is considered an important matter that should be addressed right away. Allowing the P0850 code to remain unrepaired could create unsafe driving conditions, and cause larger and more expensive repairs to be necessary. When the P0850 code is detected, it is best to have an auto service technician address the issue right away.
There are many ways that a technician can address a P0850 code detection. They include:
YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.