Hello I will help you with your question,
I'm not sure what harness you have by the headlight but here is a copy of the TSB that outlines the sensor replacement near the EGR valve. Look it over and let me know if you have further questions about this
There are two sensors, one for the computer that gave you the code and one for the gauge which is the one you found
This is the harness you found at the right of the radiator in this diagram?
Here is a diagram of the sensors, the gauge is fed information from the PCM so I'm not sure what harness you have and why jumping it would affect the gauges but the code is generated from the sensor/harness of the sensor that I posted the TSB for
COOLANT TEMPERATURE GAGE The coolant temperature gage is controlled by the powertrain control module (PCM) using a pulse width modulated (PWM) signal based on the signal received from the Engine Coolant Temperature (ECT ) sensor. The duty cycle of the PWM signal is directly related to the reading of the coolant temperature gage. As the duty cycle increases the temperature reading displayed by the gage will increase. The PWM signal to the cluster is passed through an RC filter and sent to the coolant temperature gage. The PCM monitors circuit 135 for an open, short to ground or short to voltage and will set DTC P1691 if certain parameters are met.
Like I said, I'm confused. The guage worked then I didn't work. I got a code for CTS. So I went to get a sensor. I thought it would be an easy repair. I have changed a few of these. usually near where coolant hose connects. This one doesnt have one there. So I went hunting around the cooing system. Didn't find anything-except the dangling connector. I will look again when I have some daylight. I will let you know.
OK I am curious as to what you found so let me know the wire colors and how many pins are in the connector and if it is female or male.
If the harness is part of the one that connects to the fan motor this is the coolant level harness that does run to the other side of the vehicle and plugs into the bottom of the surge tank
I will watch for your post later on today
OK I will be here later on today
There is only one sensor for the coolant temp and that is why you have the code and the fan does not come on. That is the sensor in the first TSB that I posted and it is located below the EGR valve in the end of the head. The wiring there is yellow and black.
Here is the fan circuit, does the fan come on when you turn the AC on or does the AC come on?
I'm not finding black and tan anywhere so I would change the temp sensor, inspect the connector for green corrosion and fill the cooling system and clear the codes then see if the fan operats correctly. If it will not come on with the AC you will need a testlight to check for power to the fan motor. If you do have power to the motor the fan motor has failed.
Let me know what I can do to help you with this
Does the fan come on with the AC?
i turn the ac on and fan didnt come on.
OK then start at the beginning with the 30 amp cooling fuse in the underhood junction block.
Do you have power to this fuse?
Pull the cooling relay out, there should be power at two of the pin sockets, Is there?
If you have power to the relay use a large paperclip to jump from pin #87 to pin#30 in the fuse block, check the side of the relay to find these pins.
Use gloves, if the fan is shorted the paperclip will get very hot very fast.
Let me know if the fan runs. If nothing happens check the light blue wire at the fan for power with the paperclip installed. If there is power then check to the black wire to the light blue and if the light comes on replace the fan.
Let me know what you find
Ok then go anead and check to see if you can turn the fan on by jumping the #87 to the #30 if you are not sure which is which do not guess
I need you to look on the side and bottom of the relay and you will see the pins marked. Watch how the relay fits in the fuse block and see where the #30 and #87 pins go. One should have power and the other will go to the fan. Connect these together and see if the fan runs. If it does not use your testlight to check for power at the fan connector.
If the fan runs install one of the other relays that is identical and try turning the AC on, if the fan now works replace the relay.
gotcha. its dark lemme find a flashlight n check that out. That will tell if it is the relay or the fan. cool deal.
The last thing you will need to do is to jump the connector of the coolant temp sensor with a paperclip. Turn the key on and see if the fan comes on. If the fan does not come on ground the dark green wire at J1C01 of the engine control computer if the fan still coms on from there the PCM has failed and needs to be replaced.
Let me know if the fan comes on with the sensor jumped and I will post the diagram for the PCM connector and the location if the fan does not come on
Check the PCM connector using a jumper wire to ground from the J1 connector shown below and the C1 pin cavity. There should be a dark green wire in the cavity (leave connected and use a paperclip ti slide along the wire to make contact.) that you will connect to ground with the key on. If the fan comes on with the jumper then the PCM is not capable of turning the fan on and needs to be replaced.
The PCM is a pain to get to on your car, it is under the top cover on the dash. Pry the spring clips of the cover very carefully as they tend to break and then the cover rattles.
Get the file at the link above the link tool in the JA site is not working at this time
Sorry this is dragging on so long but you are in expensive territory and I want to be very sure before I tell you to have the PCM replaced. You will need a scantool if the PCM has to be replaced to set the crank offset learn or there will be a check engine light on.