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Hey guys, my car threw a p0118 code on me with the typical symptoms. I went ahead and bought a thermostat and ect sensor. I replaced the thermostat and when i went to unplug the wires to the sensor, it appears something chewed through the wires. So the wires and sensor have been severed. I'm hopping on here in hopes anyone has any bright ideas as to what i should do now. I thought about trying to splice into the wires and just adding more but wasn't sure if that's a good idea to begin with and i have hardly any clearance to get in there. I have big forearms and really struggled getting anything done in there. Ill attach a pic of the sensor plug, but I cant really get an accurate pic of the wires connected to the harness. Any help would be greatly appreciated
Last edited by BigJ1089; Oct 18, 2020 at 02:28 PM.
You can add more wire but use only as much as necessary and as long as its not a thinner gauge wire. Soldering is my personal preference over using butt splices but they probably make weatherproof splices if you can find them.
Soldering Procedure: (How I normally do it)
Slip some heat shrink tubing onto the wire and move a few inches away from the joint, you don't want the heat from soldering to accidentally shrink the tubing. Twist the wires together "inline" then clean the wire with flux and solder the wires together, keep the joint thin enough for the heat shrink tubing to slip back over. You can either use liquid black tape, epoxy or dielectric grease to coat the exposed wire in the joint. Move the heat shrink tubing over the coated joint before the coating cures (if using epoxy/liquid tape), shrink the tubing with a lighter or the soldering iron. Let the joint cure (if using epoxy/ liquid tape) then wrap the joint tightly with electrical tape and that should be it. Covering/coating the wires and joint are crucial to ensure that the wire doesn't corrode as capillary action will draw water into the wire causing corrosion over time.
Good Luck!
My 2007 Cobalt LT with a 2.2L engine gave a check engine light code P0128, low temperature for too long.
I replaced the thermostat with a new one and noticed for several days that the Coolant displayed temperatures that were up and down. After a few days and starts, the check engine light went off and the Coolant display appeared to be stable and normal.
A couple weeks later, the Coolant Temperature display showed - - - F.
So, I replaced the ECT with a new one. After putting it all back together, I started up and ran for a while and the display still showed - - - F!
Should the display come on immediately? Or, does it need time and multiple starts to clear up the display?
Thoughts?
11/16/2020 - My 2007 Cobalt LT with a 2.2L engine gave a check engine light code P0128, low temperature for too long.
I replaced the thermostat with a new one and noticed for several days that the Coolant displayed temperatures that were up and down. After a few days and starts, the check engine light went off and the Coolant display appeared to be stable and normal.
A couple weeks later, the Coolant Temperature display showed - - - F.
So, I replaced the ECT with a new one. After putting it all back together, I started up and ran for a while and the display still showed - - - F!
Should the display come on immediately? Or, does it need time and multiple starts to clear up the display?
Thoughts?
11/17/2020 - New wrinkle to the story. My wife drove the car today with an outside temperature at about 33 degrees F. While on that drive of over 12 miles, the air from the cabin heater vents was tepid, at best. The radiator/coolant reservoir is full to the line. Is my new thermostat already having problems? Do I need to replace? The one I bought is a "Fail Safe" model that fails in the open condition. Does my symptom align with a failed open thermostat? The more I read, the more concerned I get. At the moment, I have no Coolant Temperature on the dash display and little to no heat coming out of the heater vents.
11/16/2020 - My 2007 Cobalt LT with a 2.2L engine gave a check engine light code P0128, low temperature for too long.
I replaced the thermostat with a new one and noticed for several days that the Coolant displayed temperatures that were up and down. After a few days and starts, the check engine light went off and the Coolant display appeared to be stable and normal.
A couple weeks later, the Coolant Temperature display showed - - - F.
So, I replaced the ECT with a new one. After putting it all back together, I started up and ran for a while and the display still showed - - - F!
Should the display come on immediately? Or, does it need time and multiple starts to clear up the display?
Thoughts?
11/17/2020 - New wrinkle to the story. My wife drove the car today with an outside temperature at about 33 degrees F. While on that drive of over 12 miles, the air from the cabin heater vents was tepid, at best. The radiator/coolant reservoir is full to the line. Is my new thermostat already having problems? Do I need to replace? The one I bought is a "Fail Safe" model that fails in the open condition. Does my symptom align with a failed open thermostat? The more I read, the more concerned I get. At the moment, I have no Coolant Temperature on the dash display and little to no heat coming out of the heater vents.
What to do?
HJ
11/19/2020 - I went to the Haynes Repair Manual and looked up replacing the ECT. After re-reading the procedure, I noticed that step 1 was to remove the negative terminal connection on the battery. We completed the installation without doing that. So, I went to the trunk and pulled the negative connection, waited a couple minutes and re-attached.
To my delight, the display came up and we had a valid Coolant temperature and when I took it for a test drive, I had heat! Great to have on this 40 degree F day!
