However, the most likely candidates for what you might be considering a "second" sensor are:
* The sensor for the gauge in the instrument cluster: This is usually located in the cylinder head, and is a single-wire sensor sending a signal to the gauge. Its main purpose is to provide a reading to the driver's instrument panel.
* The sensor for the Engine Control Module (ECM): This sensor is crucial for engine management. It's also typically located in the cylinder head, but provides a more precise reading to the ECM for fuel injection and ignition timing control. It usually has multiple wires.
To find the second sensor, you'll need to:
1. Identify your engine size: This is critical, as the sensor locations can differ slightly between engine types.
2. Consult a repair manual: A Haynes or Chilton repair manual specific to your 1996 Pontiac Grand Prix will show diagrams and locations for all sensors. This is the most reliable way to locate the specific sensors for your car.
3. Look near the thermostat housing and cylinder head: Coolant temperature sensors are usually located in one of these areas.
Without knowing your specific engine type, it's impossible to give a more precise location. Using a repair manual is highly recommended.
