CHT Sensor rewire
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Joined: Sep 2019
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CHT Sensor rewire
I have a 2004 F150 5.4 Triton that has intermittent signal from the CHT sensor. I have read that you can replace the wires from the sensor directly to the PCM. Splice in one wire at PIN 58 and cut wire at PIN 41 and attach new wire. Can someone better explain to how to do this? How to find and identify the right PIN's, maybe even pictures.
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Joined: Jan 2018
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From: Memphis, TN, Earth, Milky Way
This site requires your real e-mail, but it hasn't spammed me yet:
http://www.bbbind.com/tsb-wiring-diagrams-database/
Look up your truck's engine wiring, and find the CHT wire colors to make sure you're working on the right one. You can also find the typical Ford wire colors in this & the NEXT few pages:
(phone app link)
What you're talking about is called an "overlay" - it means you're laying in a new wire over the original harness, to bypass a problem. After POSITIVELY identifying the problem circuit, and making sure you're not eliminating any necessary branches, you splice in the new wire as close to each (good) end as possible. The best splice for this (since you haven't identified a hard fault in the original wire) is a pierce splice because it doesn't damage the original wire, or remove it from the circuit (so this procedure is entirely reversible):
(phone app link)
If there's a hard fault in the original wire, you can cut it between the overlay splices later. If you KNOW there's a hard fault before you start, you can cut the original wire to begin with, and use a butt crimp:
(phone app link)
...or a butt solder joint, which can be done with pre-made heat-shrink tubes, if you're not comfortable with an old-school iron:
Ford uses TXL, but if it's cheaper, you can use GXL wire for your overlay, in the same size (gauge) or maybe one size larger. I don't recommend using common cheapo PVC-insulated wire. Good wire can be had in many color/stripe combinations, to match the original Ford colors. Amazon & ebay have a wide variety made in USA from several sellers:
https://www.ebay.com/itm/292612752113
http://www.bbbind.com/tsb-wiring-diagrams-database/
Look up your truck's engine wiring, and find the CHT wire colors to make sure you're working on the right one. You can also find the typical Ford wire colors in this & the NEXT few pages:
(phone app link)
What you're talking about is called an "overlay" - it means you're laying in a new wire over the original harness, to bypass a problem. After POSITIVELY identifying the problem circuit, and making sure you're not eliminating any necessary branches, you splice in the new wire as close to each (good) end as possible. The best splice for this (since you haven't identified a hard fault in the original wire) is a pierce splice because it doesn't damage the original wire, or remove it from the circuit (so this procedure is entirely reversible):
(phone app link)
If there's a hard fault in the original wire, you can cut it between the overlay splices later. If you KNOW there's a hard fault before you start, you can cut the original wire to begin with, and use a butt crimp:
(phone app link)
...or a butt solder joint, which can be done with pre-made heat-shrink tubes, if you're not comfortable with an old-school iron:
Ford uses TXL, but if it's cheaper, you can use GXL wire for your overlay, in the same size (gauge) or maybe one size larger. I don't recommend using common cheapo PVC-insulated wire. Good wire can be had in many color/stripe combinations, to match the original Ford colors. Amazon & ebay have a wide variety made in USA from several sellers:
https://www.ebay.com/itm/292612752113
Junior Member
Joined: Oct 2020
Posts: 2
Likes: 0
From: Buffalo
I have a 2004 F150 5.4 Triton that has intermittent signal from the CHT sensor. I have read that you can replace the wires from the sensor directly to the PCM. Splice in one wire at PIN 58 and cut wire at PIN 41 and attach new wire. Can someone better explain to how to do this? How to find and identify the right PIN's, maybe even pictures.
Did you ever get this repair done? I’m Looking to perform this repair.