Hi Birchy,
OBD II DTC P Codes are generic across the whole of the motor industry, one has to be cautious with the interpretation of these codes.
DTC Codes are a bit like a very basic GPS mapping system i.e. they point you in the direction of a specific Zip code or postal code. They can get you to the street where the house is located but not actually to the doorstep of the house, one has to deploy other tactics to get to the doorstep of the house i.e. common sense and other indicators.
If you search some areas of the internet P1800 error code translates to a malfunction in the transmission range sensor circuit on an Auto G/Box. Not applicable here because we do not have an Auto box fitted, “Common sense application”
In other areas of the internet and in my experience the most common translation of a P1800 error code is a potential fault with the ""Variable Intake Air System Control Solenoid Valve Circuit". Yes, your handheld generic Amazon purchased scanner is also extremely generic and not bespoke to the systems on your ride that require interpretation of the OBD II DTC codes i.e. your injection system. So, you will be sent down a garden path on occasions when trying to interpret these codes, therefore you have to be more cautious as instead of being sent to the street where the house is you will be sent to the town where the house is. As your scanner is struggling to interpret the software and DTC codes inside your injection ECU.
So where does this leave us……………….if it where the "Variable Intake Air System Control Solenoid Valve Circuit" one would obviously take a peek at this valve. However, to my knowledge of CFMOTO injection systems these are not fitted. So OK what is controlling “Air” quality on these Quad bikes? The intake Air Temp sensor, and the MAP sensor fitted to the throttle body.
However, like all forms of diagnostic tools “Please” do not forget that these are pointing devices. It may state O2 senor or Air temp senor fault, but it can be any of the harness cables or connections on route to these sensors.
Also do not ignore basics i.e. the days before DTC codes how is the bike actually performing is it, poor at starting, is its idle poor, is its acceleration poor, does it backfire on de-acceleration. What is the condition of the plugs and so on. All of these would point at an air quality issue.
It is good to investigate these codes, however, do not forget that if it were a serious fault i.e. one that could potentially damage the engine the injection ECU will lock down to “Limp Home Mode” it limits RPM’s to something like 1,000 RPM or in extreme situations will not start or run. This was always the main reason for DTC codes i.e. to protect the engine and prevent serious damage.
GMSAHFR