PCTREE
Treehouser
Any one know where the temp sensor is located for the computer ,not the gage????
7.3 PSD temp sensor
- Thread starter PCTREE
- Start date
- Replies 8
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rskybiz
TreeHouser
I can ask the PSD forum when I get home if that will help?
I think that would be the oil temp sensor near the HPOP.
Add this from a quick google...
F-350 7.3 DIT auto Will only register 40 degrees coolant temp on scan gauge. Inl
Customer Question
Ask your own question now >
<p>F-350 7.3 DIT auto Will only register 40 degrees coolant temp on scan gauge. Inlet air registers ok 80- 90 degrees. Also stays in open loop. Changed sensor by thermo according to alldata that was the ECM sensor. No change, only seemed to work the gauge in dash. Changed second sensor on back side to left of ICP sensor , seems like it was oil temp as oil came out upon removal. Also cleaned and retightened engine and ECM harness connections. Still registers 40 deg.</p><p>This is all centered around loss of fuel mileage. I was almost 19 mpg MTY with my GearVendors running in double OD</p><p>Down to 13.5 now</p>
Submitted: 548 days and 1 hours ago.
Category: Ford Status: CLOSED
Optional Information
Country: United States
Make: Ford
Model: F350 DIT
Year: 2002
Engine: 7.3 dit
Already Tried:
as outlined above
Posted by John Crouch 547 days and 18 hours ago.
Expert's Answer
My name is XXXXX XXXXX X will assist you. The coolant temp sensor that is located in the water pump housing is only for the temp guage in the dash. The pcm does not look at coolant temp on this engine, only looks at oil temp, the abrieviation for the pid that you should be looking at would be EOT (engine oil temp). The sensor is in the resivior housing above the high pressure pump, mounted vertical and a few inches away from the ICP sensor that is mounted in the drivers side head (the sensor that is on the top of the housing is the oil pressure sensor). What I would recomend that you do is first test the reading on the scan tool with the sensor disconnected, then put in a 100 ohm resistor (available from radio shack) in the pins on the connector on the wiring harness and see if it changes, if no change, then there is a open or short in the wiring between the sensor and the pcm. if it does change, then the sensor is bad and needs to be replaced.
547 days and 18 hours ago.
Customer Reply
I have previously changed the oil temp sensor. That particular sensor was from Ford. 12A648
There was no diff between old sensor , new sensor, no sensor, still read 40 degrees.
What reading should show with the 100 ohm resistor?
Also will not go into closed loop.
Posted by John Crouch 547 days and 17 hours ago.
Expert's Answer
I will run by the shop in the morning and get the information that I need to give you. will give you the ohm's to use and what you should see when using different resistances. Basically you are looking for a change in resistance. One thing you can do is use a dvom and put the sensor in some water around 180 degrees and see what resistance it is at then. the sensor is basically a thermistor. I have a strong feeling that you have either a broken wire or shorted wire in the circuit for the oil temp circuit.
the fact that it is not seeing the oil temp get up to operating temp is also why it is staying in "open loop".
John Crouch40594.1463146991
Accepted Answer
Ok, I got the resistance's of the engine oil temp sensor for you at different temps, here they are.
1200 ohms = 248 degrees F
2000 ohms = 212 degrees F
3840 ohms = 176 degrees F
5340 ohms = 158 degrees F
Do you have any codes stored in the pcm? You should either have a P0197 or a P0198.
And you are correct, EOT has to do with control of the glow plug system, fuel control and will also gives the pcm information to determine if idle needs to be sped up when cold to assist with engine warm up.
I appologize for not getting this information to you until this morning, I have most of my information for shop manuals on DVD's and had to retrive them so I could look the specifications up for you.
Expert: John Crouch
Category: Ford
Pos. Feedback: 97.8 %
Accepts: 1319
Answered: 2/20/2011
Ford Mechanic
22 years of Ford service, and Ford senior master certified in diesel, gasoline and hybrid vehicles
Ask this Expert a Question >
547 days and 7 hours ago.
Customer Reply
John, 2 wires at the sensor, any idea which will go back to the pcm so I can check continuity back to the plug. Would one wire be a ground? If so where would it terminate to ground at.?
When I install the 100 ohm resistor in the EOT plug what should the reading be on the scan tool?
Posted by John Crouch 547 days and 7 hours ago.
Expert's Answer
I would not use a 100 ohm resistor, use a 2K (2000 ohm) resistor. I have not done much work on 7.3's on the oil temp sensor and was wrong on the resistance of the resistor that you needed. They are available from radio shack (I think a pack of 5 of them are about $2.00).
Neither wire is a ground, both wires go back to the pcm and simply complete a circuit. All it looks at is the resistance of the sensor, no voltage goes thru this circuit.
the gray/red wire at the sensor is the ground or common ground for most of the sensors and runs into a splice and then finalized into pin #91 of the pcm connector. One thing you can to is take a ohm meter and check it to the same color wire on the air intake sensor, this will tell you if the wire is good to the splice or not, since you dont have issues with the other sensors setting codes I would think that this circuit is ok. The othe wire light green/red goes to pin #38 of the pcm connector. All these wire go thru the square connector that is over the drivers side valve cover near the air cleaner tube. I would check everything there, sometimes wires get broken from movement or flexing of the harness there or could simply be a backed out pin in one of the connectors there.
Hopefully this information will help you to repair your truck. let me know if you need anything else.
547 days and 6 hours ago.
Customer Reply
Ok It makes sense. Is there a schematic that is available on the net to show the pin #'s on the ecm connector and their respective destinations? I did have both connectors apart to clean out with alcohol , and look for bent pins but did not check wires.
I should be able to remove the ecm connector and check continuity from the EOT sensor to the plug if I know the position of the wire, correct?
547 days and 6 hours ago.
Customer Reply
BTW no codes stored other than the one I get from using the gearvendor , 2nd and 3rd gear ratio error. I believe they come from the engine rpm not being close to the rpm detected by the speed sensor.
Read more: F-350 7.3 DIT auto Will only register 40 degrees coolant temp on scan gauge. Inl - JustAnswer http://www.justanswer.com/ford/4man...oolant-temp-scan-gauge-inl.html#ixzz247i1qHgi
I hope that comes through as a link, it's not hee and rather long.
Add this from a quick google...
F-350 7.3 DIT auto Will only register 40 degrees coolant temp on scan gauge. Inl
Customer Question
Ask your own question now >
<p>F-350 7.3 DIT auto Will only register 40 degrees coolant temp on scan gauge. Inlet air registers ok 80- 90 degrees. Also stays in open loop. Changed sensor by thermo according to alldata that was the ECM sensor. No change, only seemed to work the gauge in dash. Changed second sensor on back side to left of ICP sensor , seems like it was oil temp as oil came out upon removal. Also cleaned and retightened engine and ECM harness connections. Still registers 40 deg.</p><p>This is all centered around loss of fuel mileage. I was almost 19 mpg MTY with my GearVendors running in double OD</p><p>Down to 13.5 now</p>
Submitted: 548 days and 1 hours ago.
Category: Ford Status: CLOSED
Optional Information
Country: United States
Make: Ford
Model: F350 DIT
Year: 2002
Engine: 7.3 dit
Already Tried:
as outlined above
Posted by John Crouch 547 days and 18 hours ago.
Expert's Answer
My name is XXXXX XXXXX X will assist you. The coolant temp sensor that is located in the water pump housing is only for the temp guage in the dash. The pcm does not look at coolant temp on this engine, only looks at oil temp, the abrieviation for the pid that you should be looking at would be EOT (engine oil temp). The sensor is in the resivior housing above the high pressure pump, mounted vertical and a few inches away from the ICP sensor that is mounted in the drivers side head (the sensor that is on the top of the housing is the oil pressure sensor). What I would recomend that you do is first test the reading on the scan tool with the sensor disconnected, then put in a 100 ohm resistor (available from radio shack) in the pins on the connector on the wiring harness and see if it changes, if no change, then there is a open or short in the wiring between the sensor and the pcm. if it does change, then the sensor is bad and needs to be replaced.
547 days and 18 hours ago.
Customer Reply
I have previously changed the oil temp sensor. That particular sensor was from Ford. 12A648
There was no diff between old sensor , new sensor, no sensor, still read 40 degrees.
What reading should show with the 100 ohm resistor?
Also will not go into closed loop.
Posted by John Crouch 547 days and 17 hours ago.
Expert's Answer
I will run by the shop in the morning and get the information that I need to give you. will give you the ohm's to use and what you should see when using different resistances. Basically you are looking for a change in resistance. One thing you can do is use a dvom and put the sensor in some water around 180 degrees and see what resistance it is at then. the sensor is basically a thermistor. I have a strong feeling that you have either a broken wire or shorted wire in the circuit for the oil temp circuit.
the fact that it is not seeing the oil temp get up to operating temp is also why it is staying in "open loop".
John Crouch40594.1463146991
Accepted Answer
Ok, I got the resistance's of the engine oil temp sensor for you at different temps, here they are.
1200 ohms = 248 degrees F
2000 ohms = 212 degrees F
3840 ohms = 176 degrees F
5340 ohms = 158 degrees F
Do you have any codes stored in the pcm? You should either have a P0197 or a P0198.
And you are correct, EOT has to do with control of the glow plug system, fuel control and will also gives the pcm information to determine if idle needs to be sped up when cold to assist with engine warm up.
I appologize for not getting this information to you until this morning, I have most of my information for shop manuals on DVD's and had to retrive them so I could look the specifications up for you.
Expert: John Crouch
Category: Ford
Pos. Feedback: 97.8 %
Accepts: 1319
Answered: 2/20/2011
Ford Mechanic
22 years of Ford service, and Ford senior master certified in diesel, gasoline and hybrid vehicles
Ask this Expert a Question >
547 days and 7 hours ago.
Customer Reply
John, 2 wires at the sensor, any idea which will go back to the pcm so I can check continuity back to the plug. Would one wire be a ground? If so where would it terminate to ground at.?
When I install the 100 ohm resistor in the EOT plug what should the reading be on the scan tool?
Posted by John Crouch 547 days and 7 hours ago.
Expert's Answer
I would not use a 100 ohm resistor, use a 2K (2000 ohm) resistor. I have not done much work on 7.3's on the oil temp sensor and was wrong on the resistance of the resistor that you needed. They are available from radio shack (I think a pack of 5 of them are about $2.00).
Neither wire is a ground, both wires go back to the pcm and simply complete a circuit. All it looks at is the resistance of the sensor, no voltage goes thru this circuit.
the gray/red wire at the sensor is the ground or common ground for most of the sensors and runs into a splice and then finalized into pin #91 of the pcm connector. One thing you can to is take a ohm meter and check it to the same color wire on the air intake sensor, this will tell you if the wire is good to the splice or not, since you dont have issues with the other sensors setting codes I would think that this circuit is ok. The othe wire light green/red goes to pin #38 of the pcm connector. All these wire go thru the square connector that is over the drivers side valve cover near the air cleaner tube. I would check everything there, sometimes wires get broken from movement or flexing of the harness there or could simply be a backed out pin in one of the connectors there.
Hopefully this information will help you to repair your truck. let me know if you need anything else.
547 days and 6 hours ago.
Customer Reply
Ok It makes sense. Is there a schematic that is available on the net to show the pin #'s on the ecm connector and their respective destinations? I did have both connectors apart to clean out with alcohol , and look for bent pins but did not check wires.
I should be able to remove the ecm connector and check continuity from the EOT sensor to the plug if I know the position of the wire, correct?
547 days and 6 hours ago.
Customer Reply
BTW no codes stored other than the one I get from using the gearvendor , 2nd and 3rd gear ratio error. I believe they come from the engine rpm not being close to the rpm detected by the speed sensor.
Read more: F-350 7.3 DIT auto Will only register 40 degrees coolant temp on scan gauge. Inl - JustAnswer http://www.justanswer.com/ford/4man...oolant-temp-scan-gauge-inl.html#ixzz247i1qHgi
I hope that comes through as a link, it's not hee and rather long.
arborworks1
Treehouser
Paul mine reads -40 on my 7.3. My 6.0 reads right. I reprogrammed it and it still read the same. I think it's the scan gauge. I had my buddy with a snap on reader check it. Read fine.
sotc
Dormant hero!!
Ha, that'd be nice
arborworks1
Treehouser
Marvel mystery oil.... Should do the trick!!!
