Originally Posted by bobski

Having responded to countless weird-engine-behavior posts on other Honda forums with "Check your grounds", it's nice to know the GK is a Honda through-and-through.

For anyone that needs further explanation:
"Ground" is an electrical return path, the "zero volts" point within an electrical system. An electrical system such as a car. With the exception of some classic cars, all cars use a negative-ground system, meaning the battery negative is connected to ground. Most cars have a welded-together metal body that conducts electricity (like a wire). To save a few bucks on wiring and provide some protection from electrical interference, the body gets used as a giant ground wire.
The engine block and transmission housings (bolted together and therefor electrically connected) are similarly used as grounds. The transmission and engine block are suspended on rubber vibration-isolating mounts which also electrically isolates them from the car body. A dedicated ground wire is needed to connect them, called the engine ground cable. "Cable" because it's pretty thick - it needs to carry the electrical current used to run the starter, as well as the current from the alternator which charges the battery and powers the car while the engine is running.
The spots where a grounded object (such as the transmission housing) connects to a ground wire (such as the engine ground cable), are called "ground points". There are typically 15-20 ground points on a given Honda car, each has an ID number shown on wiring diagrams, along with service manual diagrams and pictures of where to find them.
Hondas ground nearly all of the engine-control electrical stuff to a single point on the engine (usually labeled G101). This makes sure all the engine sensors and devices are using the same zero-volt reference, which does a lot to avoid other headaches and electrical gremlins. IIRC, the GK engine controls ground point is on the front right (from the driver's point of view) of the cylinder head. Edit: the left according to Alldata.

So, if you're getting weird engine electrical behavior: Clean your grounds, inspect your ground cables. Get a small wire brush (a sanding block in the low-hundreds-grit also works, and is actually better for flattening heavily corroded/pitted metal) and a tube of silicone "dielectric" grease. Unbolt the wires' ring terminal(s) (the loop on the end of the wire(s)) from the ground point and use the wire brush to gently scrub the surfaces between the ground point and the ring terminal. Definitely remove any crusty looking stuff, ideally clean until you get shiny metal. Apply a light coat of dielectric grease to the whole ring terminal and any exposed metal on the wire, as well as the ground point. Try to work the grease into the metal slightly to fill any surface irregularities - the goal is to protect the metal from future corrosion by filling any gaps where water could wick in and hang out. Add another blob of grease to the terminal and then bolt it down (the grease should squeeze out between the terminal and grounded object.
FYI, dielectric actually means the grease blocks electricity, but the bolt force will squeeze it out of any joints that are solid enough to carry electricity. Electrically conductive grease is also a thing, but harder to find. If you go looking for it, make sure whatever you use is stable over the long term (uses a silicone base for instance), ideally claims to inhibit corrosion/oxidation, and is compatible with copper, aluminum and steel.

That's a wall of text for "unbolt, scrub clean, grease, bolt down snug". G101 should be cake - 5 minutes tops. Finding and accessing both ends of the body-to-transmission cable could be more work.