Code 15: Coolant Temp Sensor Signal Volt High: Notes
WARNING: This page is about a different car, the 1990 Pontiac Firebird and 1990 Chevrolet Camaro. However, it is still accessible from the selected car via links, so may be relevant.
Coolant temperature is one input the ECM uses to control fuel delivery, spark timing, idle speed, converter clutch, canister purge, air management (man. trans.), EGR and cooling fan.
NOTE:
Test numbers refer to test numbers on diagnostic chart.
- Code 15 will set if signal voltage indicates coolant temperature is low for 3 seconds.
- This test simulates a Code 14. If the ECM recognizes the low signal voltage and the "Scan" tester reads 130°C or more, ECM and wiring are okay.
- This test determines if circuit No. 410 is open. There should be 5 volts present at sensor connector if measured with a digital volt-ohmmeter.