ECA 70 - No Code (Coolant Temperature Switch)
- Check continuity across coolant temperature switch (mounted in radiator). With engine cold, continuity should exist. With radiator temperature above 62.6°F (17°C), switch should open (no continuity). If switch continuity is incorrect, replace switch.
- Check continuity between switch Black wire terminal and ground. If continuity does not exist, repair switch ground circuit.
- Check voltage at ECA terminal 1L. With engine cold, voltage should read 12-14 volts. With engine warm, voltage should read 0-2.5 volts. If voltage readings are incorrect, check for opens or shorts in wiring between Light Green wire terminal and ECA terminal 1L. Repair as necessary. Go to ECA 73 .