Temperature Gauge not working after changing engine coolant temperature sensor

[genesiss]

2002 ford sport trac.

I have been having an ongoing issue that started with the engine cranking but would not turn over until an hour passed. After replacing multiple parts (cam shaft sensor, crankshaft sensor, ignition pack) I am now down to poor fuel economy as the last of the issues (roughly 12 in the city and 15 highway).

I was told the issue may be the engine coolant temperature sensor going bad so I decided to replace it. I found this was very difficult due to it being a plug and locking pin design and in a very tight spot in the engine.

I tried to purchase a replacement and the parts store kept trying to insist on selling me a part with threading.

I finally found someone that figured out the issue and found the part for the 2001 sport trac had the same plug style with clip that did fit but was shaped a little different on the sensor end which I assume was due to being aftermarket.

I noticed that there were two plugs side by side and the one easiest to access was on the left and I was told the one on the right was the sensor that gave the temperature reading to the gauge.

After installing the engine coolant tempurature sensor I found the temperature gauge on the dash now will not respond and is sitting below the cold end of the gauge. Is it possible this is caused by a conflict with the sensor being made for a 2001 explorer? It is the left passenger side sensor that is the engine coolant sensor correct?

 

[bdmaash]

2002 ford sport trac.

I have been having an ongoing issue that started with the engine cranking but would not turn over until an hour passed. After replacing multiple parts (cam shaft sensor, crankshaft sensor, ignition pack) I am now down to poor fuel economy as the last of the issues (roughly 12 in the city and 15 highway).

I was told the issue may be the engine coolant temperature sensor going bad so I decided to replace it. I found this was very difficult due to it being a plug and locking pin design and in a very tight spot in the engine.

I tried to purchase a replacement and the parts store kept trying to insist on selling me a part with threading.

I finally found someone that figured out the issue and found the part for the 2001 sport trac had the same plug style with clip that did fit but was shaped a little different on the sensor end which I assume was due to being aftermarket.

I noticed that there were two plugs side by side and the one easiest to access was on the left and I was told the one on the right was the sensor that gave the temperature reading to the gauge.

After installing the engine coolant tempurature sensor I found the temperature gauge on the dash now will not respond and is sitting below the cold end of the gauge. Is it possible this is caused by a conflict with the sensor being made for a 2001 explorer? It is the left passenger side sensor that is the engine coolant sensor correct?

Yes, there are 2 "sensors", (my pic doesn't show them well)
one is a "sender" (brown connector???), the other is a "sensor" unit (grey connector???), the color probably refers to the color on the end of the device or connector.

they do not function the same, but the connector is the same for both.

The brown one is for the temp guage (RD/WH and BK/WH wire)
The gray one is for the ECM (LG/RD and GY/RD wires) <<<this is the one you would want to replace.

Guesswork costs a lot, don't take my post as fact verify it with a Ford dealership, I am not resposible for you wasting more money guessing.

 

[genesiss]

Yes, there are 2 "sensors", (my pic doesn't show them well)
one is a "sender" (brown connector???), the other is a "sensor" unit (grey connector???), the color probably refers to the color on the end of the device or connector.

they do not function the same, but the connector is the same for both.

The brown one is for the temp guage (RD/WH and BK/WH wire)
The gray one is for the ECM (LG/RD and GY/RD wires) <<<this is the one you would want to replace.

Guesswork costs a lot, don't take my post as fact verify it with a Ford dealership, I am not resposible for you wasting more money guessing.

Considering that I have gone to a mechanic already and all they could do is scratch their head since there are no codes being produced and ask for $230 to replace a $15 crankshaft sensor as a possible culprit in the recent past I think Ill waste the $10 on a sensor. My only issue was identifying why the manuals show the wrong part and if a 2001 part suggested could be why the gauge is not working and what may help correct that since clearly if we all went to mechanics there would be no need for this forum. This is a rough economy and we are all trying to survive. Thank you though some of your post was very informative. Could you grace me with the knowledge of the difference between the 2001 and 2002 plug style engine coolant temperature sensor? They appear to be the same on web search but not in the auto parts stores.

 

[bdmaash]

Considering that I have gone to a mechanic already and all they could do is scratch their head since there are no codes being produced and ask for $230 to replace a $15 crankshaft sensor as a possible culprit in the recent past I think Ill waste the $10 on a sensor. My only issue was identifying why the manuals show the wrong part and if a 2001 part suggested could be why the gauge is not working and what may help correct that since clearly if we all went to mechanics there would be no need for this forum. This is a rough economy and we are all trying to survive. Thank you though some of your post was very informative. Could you grace me with the knowledge of the difference between the 2001 and 2002 plug style engine coolant temperature sensor? They appear to be the same on web search but not in the auto parts stores.

I would try a ford dealer, they may be able to grace you with the knowledge (at the parts counter)..a lot better than I ever could.

[difference between plugs] - It may be something like the difference between a ford and a dodge, sure they both have 4 wheels, and they roll down the road but they are not the same thing. Sometimes the OEM part is the best way to go.

Also in the first post I understand it as - you changed a part, and your guage stopped working?? - wouldn't that mean you changed the part for the guage and not for the ECM? Or was your problem : the temp guage doesn't work properly, so you change the sensor for the guage (and hopefully the truck will run better too since the guage works).

 

[FORDSVTPARTS]

There are actually two different sets of sensors used in the 2001 model year so it's possible you got the wrong sensor although Ford is usually pretty good about using different wiring connectors so the wrong thing can't be plugged in.

If you post your VIN or PM it to me I can verify the correct sensors. Or just pick up the phone and give us a call

 

[genesiss]

I would try a ford dealer, they may be able to grace you with the knowledge (at the parts counter)..a lot better than I ever could.

[difference between plugs] - It may be something like the difference between a ford and a dodge, sure they both have 4 wheels, and they roll down the road but they are not the same thing. Sometimes the OEM part is the best way to go.

Also in the first post I understand it as - you changed a part, and your guage stopped working?? - wouldn't that mean you changed the part for the guage and not for the ECM? Or was your problem : the temp guage doesn't work properly, so you change the sensor for the guage (and hopefully the truck will run better too since the guage works).

The sensor with the gray not the brown was changed. The entire goal was to find the culprit behind poor fuel economy (aprox 40% loss)at this point.

 

[FORDSVTPARTS]

As previously posted the grey is for the ECT and brown is for the gauge.

The correct part numbers for yours by the VIN you PMed me are as follows,

ECT 3L8Z-12A648-BA $20.36 from us and it retails for $41.13

Gauge 3F1Z-10884-AA $15.69 from us and retails for $31.69

The difference in build dates on these is due to the threaded vs push in stye sensor so it should be pretty obvious if they try to sell you the wrong ones but you already know that, now you know why they had the wrong ones.

 

[qosmio]

2001 sport trac job2 :

my temperature gauge always shows to the max, even when engine is cold, when driving for 10 min needle move even higher, I check the temp with a digital meter and it is 180 F.

This happened after I saw some oily stuff and put some grease remover and wash it off with water on the area where the 2 sensors are located.

Any ideas of how to fix this problem? thank you.

above sensors gray and brown

above actual temperature after a drive of 20 min

above temp gauge when engine cold shows to the red

...
ok, found an excellent how to site here:
http://bengrosser.com/howto/fordthermostat/
it shows how to replace sender=red to gauge and sensor=gray to pcm
maybe it can help others too.

 

[Larry Davis]

If your temp gauge swings to hot when you turn on the ignition the wiring is earthing out, I have a 2001 v6 and looking at the car from the front,, the sender on the left of the two is your gauge unit, check that the plug is fitted into the receiver correctly at the top, if the sender is faulty, the gauge will not read at all, and the sender will need replacement, (gauges rareley stuff up) the way to access and replace the senders is thus......remove air intake tube from air box to throttle body (two ring clips an elect plug, and a metal air tube) remove throttle body, (4 screws) and swing out of way, remove the two alternator wires, (1 elect plug, and 1 hot wire, swing out of way, careful of live wire ), remove the 3 screws holding top of thermostat housing, and move the whole top and inlet hose away, now you have access to the senders, and the thermostat, slip the thermostat out and check condition, rep' if ness',,DO NOT attempt to unplug the sensors, simply,, but carefully slip the wire retaining spring clip off from the base of one sender at a time, and gently pop them up and out from the housing, complete with their conections attatched, they are not screwed in, they both have 'O' rings and seal themselves, do not drain the radiator, or the engine water it will level its self at the thermostat body, water loss will be minimal, and topped up at jobs end, you can now unplug your sensors fronm their caps test your temp elect circut, and replace if faulty.....putting it back is the opposite,making sure the sender connectors are properly fitted before returning them to the thermo' body,,,,pop em in and clip em, re-seal the thermo body top, and get that hot alternator wire back to its place, rest is easy....PS if you try to remove the sender elect plugs any other way you will destroy the plastic snap clips, if this is so ,,,a dot of Areldite on top of the plug will hold it ok

 

[Larry Davis]

If your temp gauge swings to hot when you turn on the ignition the wiring is earthing out, I have a 2001 v6 and looking at the car from the front,, the sender on the left of the two is your gauge unit, check that the plug is fitted into the receiver correctly at the top, if the sender is faulty, the gauge will not read at all, and the sender will need replacement, (gauges rareley stuff up) the way to access and replace the senders is thus......remove air intake tube from air box to throttle body (two ring clips an elect plug, and a metal air tube) remove throttle body, (4 screws) and swing out of way, remove the two alternator wires, (1 elect plug, and 1 hot wire, swing out of way, careful of live wire ), remove the 3 screws holding top of thermostat housing, and move the whole top and inlet hose away, now you have access to the senders, and the thermostat, slip the thermostat out and check condition, rep' if ness',,DO NOT attempt to unplug the sensors, simply,, but carefully slip the wire retaining spring clip off from the base of one sender at a time, and gently pop them up and out from the housing, complete with their conections attatched, they are not screwed in, they both have 'O' rings and seal themselves, do not drain the radiator, or the engine water it will level its self at the thermostat body, water loss will be minimal, and topped up at jobs end, you can now unplug your sensors fronm their caps test your temp elect circut, and replace if faulty.....putting it back is the opposite,making sure the sender connectors are properly fitted before returning them to the thermo' body,,,,pop em in and clip em, re-seal the thermo body top, and get that hot alternator wire back to its place, rest is easy....PS if you try to remove the sender elect plugs any other way you will destroy the plastic snap clips, if this is so ,,,a dot of Areldite on top of the plug will hold it ok

SENSOR IDENTIFICATION,,,,TEMP= PROBE AT BASE IS COPPER TUBE 1/2 in' long CLEAN.......COMPUTER SENSOR IS SAME BUT WITH SMALL RAISED RING AT END, THEY CAN FIT INTO EITHER HOLE IN THE THERMO BODY DOSN'T MATTER, TIP.....KEEP TEMP ON THE LEFT SIDE, ITS EASIER TO ACCESS (2ND TIP ) if you get an engine check light cancel it out by removing THE EARTH strap from the battery for 30 sec no probs

 

[HEDNOUT]

I reccomend changing both of them if you have to change one. On an explorer sport 2001 (just bought in sept. 95,000 miles) I had the cold start issue and finally changed the intake gaskets. Just to be sure I changed the ECT one for the computer while the manifold was off. I bought the temp gage one and was going to change it too, but did not (if its working fix it anyway) and put it all back together, runs perfect now, but a month later the gage looks just like the one in the picture way over too hot and a check gages light is on. Pulled the connecter off and stuck the new temp sensor in and the gage works fine now but just reads low, so it is working. I've never seen a vehicle go through so many sensors. When I get up to taking off the upper manifold again I'll put it in where it goes. Both of these have threads so it must be a change to the later 2001 if they do not have threads

so far in 5 weeks, oil sender, ECT, water temp, VSS in rear diff as it has the ABS low speed pulsing, intake gaskets, clean IAT, Throttle body, MAF. Great car but kind of tempermental. My 98 Ranger 184,000 miles and no sensors changed, only a timing belt

 

[TThomason]

the temperature is wrong or none at all on my dash for my 02 ford explorer. is that from a faulty ambiebt air temperature sensor? the mileage is show but not the temperature.

 

[Natcox012]

So I have something similar going on I have replaced both sensors think maybe I have them back ways cause red plug on grey connector and grey connector on red plug. The gauge shows cool never warms up. Any idea. Part #74107 for grey plug and ts390 for the other. From o'Reilly any idea what's causing this?

 

[Natcox012]

Yea they were backwards lol