Bad grounds can result in no start issues and faulty sensor readings.
These grounds are located on top of the transmission, most of them secure via 1 bolt and connector in the center of the transmission mount, others are connected to brackets on the transmission. You will need to remove the factory air box to get to them
Check these ground connections for clean metal to metal contact and any brackets they are secured to for tightness and clean metal to metal contact of chassis or engine.
These grounds can be so troublesome and cause unreliability, a permanent fix is to solder them all together and wire them direct to a strong ground source such as the engine block or battery ground.
