Starter Relay: Description and Operation

The starter motor solenoid relay switch:
- Controls current to the starter solenoid.
- Is engaged by the ignition switch.
- Connects the battery to the starter motor.

The TR sensor on automatic transmission equipped vehicles prevents starter motor engagement unless the transmission is in the NEUTRAL or PARK position.

The CPP switch on manual transmission equipped vehicles prevents starter motor engagement unless the clutch pedal is pressed.