Coolant Temperature Sensor (Cts)

On Cherokee, Comanche and Wagoneer models, CTS is located at rear of cylinder head. On the Wrangler model, CTS is located on rear of intake manifold. CTS provides an input voltage to the ECU. As coolant temperature varies CTS resistance changes resulting in a different input voltage to the ECU. Based on this input, ECU will react by adjusting injector pulse width. Colder coolant temperatures will result in longer injector pulse width and richer air/fuel mixture. ECU will also compensate for fuel condensation in the intake manifold, control engine warm-up, idle speed, increase ignition timing advance when coolant is cold, energize EGR valve solenoid and prevent flow of vacuum to EGR valve.