Is there a way to switch off the 'Service Engine Soon' indicator on the dash without having to plug into diagnostics.

 

Disconnect battery for half hour and I think it's resets and switches off

 

disconnecting battery does clear memory but also erases learned parameters for engine and it may run rough as it relearns.

curious why you want to reset the light? If fault is still there it will come back on. If you did something to fix the fault and were successful the light will go out on its own.

 

probably not.

You don't need any fancy tools. Just a paper clip.

 

you can check codes and put ECM into service mode with a paper clip but I didn’t know you can reset anything. How do you do that?

 

What year is the truck, then we'll know if it is OBD 1 or OBD 2

 

Have you had it scanned to see why it's on? There is rarely a valid reason to "clear the light" other than after a proper repair. Have it scanned with a GOOD, HIGH-END scanner. The cheap code-readers that are sold for less than $100 dollars will not show you all the codes that may be setting the light. Find someone with a Snap On Solus, or Modus, and have it scanned. Then, start doing some diagnostics to figure out why that/those specific codes are setting.. Clearing the codes now, and not fixing the associated problems, will be a short term fix as the light will come back on shortly.