CHT SENSOR
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Joined: Jan 2009
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From: Top Of The World, TN
Google is my friend.
It is under the intake on the drivers side head, directly behind the alternator. All you have to do to get to it is pull the inake tube, alternator, and with a bent or adjustable end 18mm wrench you can pull it.
The cylinder head temperature (CHT) sensor 4.6L, 5.4L:
-is mounted into the wall of the cylinder head and is not connected to any coolant passages.
-sends a signal to the powertrain control module indicating the cylinder head temperature.
i-f the temperature exceeds 126°C (-258°F) 5.4L, 130°C (265°F) 4.6L, the powertrain control module disables four fuel injectors at a time. The powertrain control module will alternate which four injectors are disabled every 32 engine cycles. The four cylinders that are not being fuel injected act as air pumps to aid in cooling the engine.
-if the temperature exceeds 154 °C (310°F) 5.4L, 166°C (330°F) 4.6L, the powertrain control module disables all of the fuel injectors until the engine temperature drops below 153°C (308°F) 4.6L, 154°C (310°F) 5.4L.
DTCs are set.
-If the engine reaches critical temperature, the following happens:
The coolant temperature gauge pointer will read fully hot at 121°C (250°F).
The check gauge warning indicator will illuminate.
It is under the intake on the drivers side head, directly behind the alternator. All you have to do to get to it is pull the inake tube, alternator, and with a bent or adjustable end 18mm wrench you can pull it.
The cylinder head temperature (CHT) sensor 4.6L, 5.4L:
-is mounted into the wall of the cylinder head and is not connected to any coolant passages.
-sends a signal to the powertrain control module indicating the cylinder head temperature.
i-f the temperature exceeds 126°C (-258°F) 5.4L, 130°C (265°F) 4.6L, the powertrain control module disables four fuel injectors at a time. The powertrain control module will alternate which four injectors are disabled every 32 engine cycles. The four cylinders that are not being fuel injected act as air pumps to aid in cooling the engine.
-if the temperature exceeds 154 °C (310°F) 5.4L, 166°C (330°F) 4.6L, the powertrain control module disables all of the fuel injectors until the engine temperature drops below 153°C (308°F) 4.6L, 154°C (310°F) 5.4L.
DTCs are set.
-If the engine reaches critical temperature, the following happens:
The coolant temperature gauge pointer will read fully hot at 121°C (250°F).
The check gauge warning indicator will illuminate.
Last edited by Sako 75; Jul 10, 2010 at 12:18 PM. Reason: Added more info
FTE Chapter Leader
Joined: Jun 2003
Posts: 929
Likes: 2
From: Ohio
Google is my friend.
It is under the intake on the drivers side head, directly behind the alternator. All you have to do to get to it is pull the inake tube, alternator, and with a bent or adjustable end 18mm wrench you can pull it.
The cylinder head temperature (CHT) sensor 4.6L, 5.4L:
-is mounted into the wall of the cylinder head and is not connected to any coolant passages.
-sends a signal to the powertrain control module indicating the cylinder head temperature.
i-f the temperature exceeds 126°C (-258°F) 5.4L, 130°C (265°F) 4.6L, the powertrain control module disables four fuel injectors at a time. The powertrain control module will alternate which four injectors are disabled every 32 engine cycles. The four cylinders that are not being fuel injected act as air pumps to aid in cooling the engine.
-if the temperature exceeds 154 °C (310°F) 5.4L, 166°C (330°F) 4.6L, the powertrain control module disables all of the fuel injectors until the engine temperature drops below 153°C (308°F) 4.6L, 154°C (310°F) 5.4L.
DTCs are set.
-If the engine reaches critical temperature, the following happens:
The coolant temperature gauge pointer will read fully hot at 121°C (250°F).
The check gauge warning indicator will illuminate.
It is under the intake on the drivers side head, directly behind the alternator. All you have to do to get to it is pull the inake tube, alternator, and with a bent or adjustable end 18mm wrench you can pull it.
The cylinder head temperature (CHT) sensor 4.6L, 5.4L:
-is mounted into the wall of the cylinder head and is not connected to any coolant passages.
-sends a signal to the powertrain control module indicating the cylinder head temperature.
i-f the temperature exceeds 126°C (-258°F) 5.4L, 130°C (265°F) 4.6L, the powertrain control module disables four fuel injectors at a time. The powertrain control module will alternate which four injectors are disabled every 32 engine cycles. The four cylinders that are not being fuel injected act as air pumps to aid in cooling the engine.
-if the temperature exceeds 154 °C (310°F) 5.4L, 166°C (330°F) 4.6L, the powertrain control module disables all of the fuel injectors until the engine temperature drops below 153°C (308°F) 4.6L, 154°C (310°F) 5.4L.
DTCs are set.
-If the engine reaches critical temperature, the following happens:
The coolant temperature gauge pointer will read fully hot at 121°C (250°F).
The check gauge warning indicator will illuminate.
Thanks!
FTE Chapter Leader
Joined: Jun 2003
Posts: 929
Likes: 2
From: Ohio
First, you do NOT need to remove the intake!!! The CHT sensor can be replaced by removing the alternator!!! You will see it and it seems like easy access but I had no wrench that could access it (forget sockets).
I heated up a box-end wrench (19mm, sound right maybe???) and SUUUUUMMAAASHED it with the hammer and it fit right in!!!
I only replaced mine b/c it was giving a FALSE overheat. That matters b/c the computer will start shutting down cylinders and you will have about 20% power - NOT good!!!
I heated up a box-end wrench (19mm, sound right maybe???) and SUUUUUMMAAASHED it with the hammer and it fit right in!!!
I only replaced mine b/c it was giving a FALSE overheat. That matters b/c the computer will start shutting down cylinders and you will have about 20% power - NOT good!!!
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CHT
DOES ANYBODY KNOW WHERE THIS IS LOCATED ON A 2006 FORD F150 4.2 ENGINE NEED TO REPLACE IT AND HAVE NO IDEA WHERE IT IS THANKS FOR YOUR HELP
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Laughing Gas
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From: East L.A.
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Joined: Jun 2014
Posts: 1
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2004 F250 5.4 triton removed the intake & alt. No CHT found where is say it should be. Also no electrical connection to the wiring harness. I bought this truck brand new from a dealer so no engine swaps.. all I see is a head heat sensor un the middle of the engine block. but I have a P1289 CHT DTC. any other options for location? also, I have an o2 Sensor Bank 1 Sensor two but have no downstream o2 sensors.. only two upstream on the exhaust left and right sides..
Laughing Gas
Joined: Jun 2004
Posts: 1,240
Likes: 3
From: Dallas, Texas
First, you do NOT need to remove the intake!!! The CHT sensor can be replaced by removing the alternator!!! You will see it and it seems like easy access but I had no wrench that could access it (forget sockets).
I heated up a box-end wrench (19mm, sound right maybe???) and SUUUUUMMAAASHED it with the hammer and it fit right in!!!
I only replaced mine b/c it was giving a FALSE overheat. That matters b/c the computer will start shutting down cylinders and you will have about 20% power - NOT good!!!
I heated up a box-end wrench (19mm, sound right maybe???) and SUUUUUMMAAASHED it with the hammer and it fit right in!!!
I only replaced mine b/c it was giving a FALSE overheat. That matters b/c the computer will start shutting down cylinders and you will have about 20% power - NOT good!!!
And replace the pigtail harness too. As it gets roasted under that intake..
Moderator
Joined: Aug 2002
Posts: 6,104
Likes: 384
From: Southern California
and yes, you need to remove the generator/altenator and I rotated the upper radiator hose out of the way... now you have a clear tunnel to reach in
Laughing Gas
Joined: Jun 2004
Posts: 1,240
Likes: 3
From: Dallas, Texas
I had a customer that nobody could fix his AC issue. They replaced most everything. But they never understood the CHT was telling the ECM it’s over heating. As that little pigtail broke.
5th Gear
Joined: Sep 2021
Posts: 5
Likes: 2
Muffinman, thanks for the reply. I had my local guy replace the CHT sensor on my 01 5.4L F250. He managed to do it without removing the intake manifold, and it was, as others have said, just behind the alternator on the front driver's side, not back in the rear on the passenger side. I realize this thread was originally about a 2006 4.6. He also replaced burned out turn signal lamps and charged $160 total (I supplied the sensor). Local Ford Service Department quoted $1650 for just the sensor replacement. I am retired and thus now on fixed income, so a >90% discount is certainly welcome. Now to get Rock Auto to take back the intake manifold gasket set that I had bought in case it was needed.