ECT sensor issues
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ECT sensor issues
Hey guys! Working on a 1988 f450 with the 7.5. I'm getting a koer code 21 (Engine Coolant Temperature (ECT) Sensor Out Of Self Test Range).
I have 5 volts at the connector with the key on but nothing on the signal return wire when back probing. The signal return wire has continuity to ground. This isn't correct right? Short to ground?
I have 5 volts at the connector with the key on but nothing on the signal return wire when back probing. The signal return wire has continuity to ground. This isn't correct right? Short to ground?
Fleet Owner
Joined: Aug 2005
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From: Easton,Ks
The signal return wire should have continuity to ground. It is a ground wire and goes to the NEG post of the battery by way of the PCM computer.
Having 5 volts at the sensor may mean the ETC sensor is open.
Having 5 volts at the sensor may mean the ETC sensor is open.
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Ok I did read the wiring diagram and it makes sense now. I tested the resistance of the sensor and its about 36k ohms cold (80 degrees Fahrenheit) At that temp I believe the sensor is within range.
With the sensor plugged in and the key on I have about 2.7-3V.
With the sensor plugged in and the key on I have about 2.7-3V.
FTE Legend
Joined: Jun 2006
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From: Ottawa, Ontario
Yes part of the self test procedure is to warm up the engine to operating temp, otherwise phantom temp sensor readings are common.
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