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I noticed one day the coolant temperature was not reading any warmer than 63°C (145°F).
-So on a cold engine, after unplugging the ECT, the temperature dropped to ambient air temp (15°C).
- I then unplugged the fuel temperature sender, temperature then dropped to -5°C. (ECU uses fuel temp when theres a problem with ECT,at least thats what I read)
-Then after jumping the 5vREF and signal wire on the ECT harness, temperature rose to 70°C (158°F) and stayed put.
-I thought temperatures should drop to -40°C and rise to 130°C or more?
-There is also a little bit of stray voltage on the harness itself (about .10V).
I figure before I start really poking around and break something, I would ask for your advice. I am just beginning to learn about this stuff. Thanks in advance!
Hi Mike, welcome to the forum,usually the temperature senders are of a two wire type,5volt on one wire,earth on the other,it should default to 5volts if unplugged,and set a fault code for open circuit,and read -40 for open circuit.
There are usually two temperature sensors one going into the radiator as well,check the coolant temperature at the radiator,best to use obd2 as the car may run a default stratergy,,,, cant spel tonight,the wires usually break off at the connectors to.
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