Coolant Temperature Sensor Wiring.  The engine temperature sensor is essentially a resistor which changes value according to the temperature of the engine.  Technically, this is called a thermister.  The sensor has a single electrical connector utilizing two wires which can be connected to the SMC pins 6 and 17 without concern for polarity.

The Autronic SMC can use the factory Toyota sending unit.  However, I had previously installed a temp sender for a different EMS system.  And although I still possess the Toyota sender, I had already modified the water neck for use with this sender. 

Here's a photo of the water neck on the left side of the engine.  All but one of the factory sensors were removed and their ports welded-up.  The remaining factory sender drives the stock  temperature gauge.  After the original ports were closed, a new boss was welded atop the water neck and threaded for a suitable generic GM water temperature sending unit.  The connector with the purple wire plugs into the sender.

Return to The Shuttle's Autronic EMS Wiring page