That was a wierd one and not sure what or if anything is actually wrong. I don't drive my Dakota much. Maybe once every two or three weeks now. Last few times I got in I had the "gascap" error on the dash. This came up a few miles after refueling and getting the emissions test so I assumed it was just a loose or faulty gas cap. It does have 160k+ miles so I have to expect something to finally give way.

Fast forward to today. I replace the gas cap and connect the scanner. No codes. No pending codes. No faults in history either but gascap error is still on the odometer. I reset the ECU and the gascap fault still displays. Run a purge solenoid and evap test which the truck passes. Fault is still displaying on the odometer.

I check all the modules. No pending or stored codes on anything. Cluster, body, trans, etc... I end up resetting ALL the modules and the fault finally goes away. Hope this isn't a symptom of a gateway failure or some other ghost in the machine. I've had almost no issues with this truck since new.

 

Gets more weird.

Error came back on next restart. No codes ANYWHERE. Pending or otherwise. Passed EVAP test again. Drove around all day and the gascap fault went away on it's own.

I'm trying to figure out why this error would pop and NOT throw some type of pending or hard EVAP related emission code.