code 15 flashing

[cinci5]

coolant sensor circuit voltage high, would that mean bad sensor or possibly something else electical, and would that be voltage coming out of sensor going to ECM.

 

[wishuwerehere82]

The CTS is basicly a variable resistor that changes with temperature. A high reading means that the resistor is not referenced to ground in the circuit. It could be for a variety of reasons. One is that the sensor is bad, the other is that the connector is not making good contact to the sensor or the wire is broken. The other situation that could cause a high resistance is that the sensor is corroded and is not making good ground contact with the intake manifold.

If you put an ohmmeter between the sensor contact and the sensor case and get an open circuit, then get a new sensor.