john hennessy
New Member
- Joined
- Aug 3, 2014
- Messages
- 3
- Reaction score
- 0
- Points
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- Vehicle Year
- 2003
- Make / Model
- ford
- Transmission
- Manual
as the title says, i am having problems with the IMRC.
this is a 2003 4 cyliner duratec.
i know exactly what it does, i know all about the solenoid,
the diagnosis is to test the reference voltage which i have done, 5 volts.
the output voltage from the sensor is 1 volt or 5 volts dependant on its position, 1 volt closed, 5 volts open or there abouts.
but and now is the difficult part, the white wire from the sensor to the PCM at pin 8, already has 5 volts in the wire, before you say its shorted to the ref voltage wire, i have removed it from the harness and indeed i have cut the wire so i have a wire from the sensor and a wire from pin 8 of the PCM, both wires are outside the harness and are free of damage.
with a vacuum pump connected to the vac chamber on the sensor, i can open and close it at will and read the output voltage in both positions, with the ign turned on, and no vacuum i have 5 volts with the vacuum applied i have 1 volt in the wire from the sensor that i cut, so i know that the sensor works.
i have tested the solenoid and it functions correctly and does apply vacuum to the vac chamber.
however, the PCM turns off the solenoid after about 10 seconds from startup on a cold engine, this time gets shorter with engine temp rise.
with the ignition on, if i test the voltage in the other half of the wire, thats the piece connected to pin 8 on the PCM, there is 5 volts permanently.
this 5 volts is being generated within the PCM as the wire is out of the harness and is blinding the lower voltage signal from the sensor.
i need someone who knows how the PCM can find 5 volts to send down this wire, inside the PCM is there a common with another sensor which is returning 5 volts to a common point and back feeding out of pin 8?
given that as the temp rises, is the temp sensor or the electric thermostat causing the problem?
or is the PCM junk, i do not want to change the PCM unless i have to because of p.a.t.s. programming the key.
i am now desperate and have torn almost all of my hair out trying to rectify this.
this is a 2003 4 cyliner duratec.
i know exactly what it does, i know all about the solenoid,
the diagnosis is to test the reference voltage which i have done, 5 volts.
the output voltage from the sensor is 1 volt or 5 volts dependant on its position, 1 volt closed, 5 volts open or there abouts.
but and now is the difficult part, the white wire from the sensor to the PCM at pin 8, already has 5 volts in the wire, before you say its shorted to the ref voltage wire, i have removed it from the harness and indeed i have cut the wire so i have a wire from the sensor and a wire from pin 8 of the PCM, both wires are outside the harness and are free of damage.
with a vacuum pump connected to the vac chamber on the sensor, i can open and close it at will and read the output voltage in both positions, with the ign turned on, and no vacuum i have 5 volts with the vacuum applied i have 1 volt in the wire from the sensor that i cut, so i know that the sensor works.
i have tested the solenoid and it functions correctly and does apply vacuum to the vac chamber.
however, the PCM turns off the solenoid after about 10 seconds from startup on a cold engine, this time gets shorter with engine temp rise.
with the ignition on, if i test the voltage in the other half of the wire, thats the piece connected to pin 8 on the PCM, there is 5 volts permanently.
this 5 volts is being generated within the PCM as the wire is out of the harness and is blinding the lower voltage signal from the sensor.
i need someone who knows how the PCM can find 5 volts to send down this wire, inside the PCM is there a common with another sensor which is returning 5 volts to a common point and back feeding out of pin 8?
given that as the temp rises, is the temp sensor or the electric thermostat causing the problem?
or is the PCM junk, i do not want to change the PCM unless i have to because of p.a.t.s. programming the key.
i am now desperate and have torn almost all of my hair out trying to rectify this.
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