I also have the same problem in my frontier. They will go back to work sometimes if I tap the dashboard which makes me think that it may be a short or a ground wire. My speedometer goes from 0 to 80 even though I am only doing 35 mph. Trying to get some help also
A bad thermostat can cause overheating in a Nissan Frontier when the air conditioning is turned on. A bad compressor can also cause this.
A Nissan Frontier may be overheating because the radiator is cracked. A thermostat failure can also cause it to overheat.
A bad transmission gear can cause your 1999 Nissan frontier to shift hard. Low transmission fluid can also cause the transmission to shift hard.
yes
yes
If the system has a full charge then the thermister is most likely the cause for it not working.
A wire is shorting to ground.
check your brake fluid levels
Water in engine-head gasket most likely.
Fuel tank Fuel line Fitting on fuel filter
try the neutral safety switch
There are pages and pages of things that can cause a check engine light. You need to have it checked with a scantool. Then the code can be diagnosed and repaired.