Hi all,
I am new to the forum, and am having a problem with my 2003 F150, 5.4 ltr. (143,000 mi.).The other day the truck started fine as usual. but within a couple of minutes, both the check engine and the oil pressure/temperature lights came on. The gauges were reading normally. We checked the code with a scanner and got P1298. My neighbor changed out the cylinder head temperature sensor for me. Both lights went off, but the temp./ oil pressure light came right back on. He drove back to my house and everything else seemed fine. He shut it off, and then it wouldn't restart. The temp. gauge flew right up to the top, and then dropped right down to normal. It acted like it wasn't getting enough gas.
Then we discovered that the solenoid was kicking in, but the starter wouldn't spin. He told me to buy a starter, but it seems really odd to me that the starter would just go bad when the truck always started so easily. After doing some research, I am wondering if either the CHTS wasn't installed properly (not tightened enough?, the new part is bad, or maybe there was some damage to the jumper harness he didn't notice.
Any suggestions would be really appreciated. Thank you.

 

A post like this is asking for guessing by remote.
The CHT has nothing to do with the cranking circuit.
Depends on what was done to replace the CHT. Was the intake removed to get to the CHT sensor?
The oil pressure and CHT circuits are connected together.
The reasoning behind this is a real failure of either the cooling system or oil flow/pressure puts the motor in danger so you need to know that right away.
A guess is the harness is in trouble at some point if you saw both oil and temperature gauge/light abnormal.
As for no cranking, a lead may be off or open at the starter relay from the work done. it's on the firewall left of center.
Look at the battery cables running to it.
Starter brushes may be worn and hung up.
Its all guessing so check carefully and not just throw parts at it.
Once someone does a job, they own it at least for a short time afterwards.
.
By the way a code 1298 you posted is not the CHT system but a fuel injector driver mod. issue which is N..A on your truck..

Good luck..

 

The CHT has nothing to do with the cranking circuit.
Depends on what was done to replace the CHT. Was the intake removed to get to the CHT sensor?
The oil pressure and CHT circuits are connected together.
The reasoning behind this is a real failure of either the cooling system or oil flow/pressure puts the motor in danger so you need to know that right away.
A guess is the harness is in trouble at some point if you saw both oil and temperature gauge/light abnormal.
As for no cranking, a lead may be off or open at the starter relay from the work done. it's on the firewall left of center.
Look at the battery cables running to it.
Starter brushes may be worn and hung up.
Its all guessing so check carefully and not just throw parts at it.
Once someone does a job, they own it at least for a short time afterwards.
.
By the way a code 1298 you posted is not the CHT system but a fuel injector driver mod. issue which is N..A on your truck..

Good luck..[/QUOTE

 

You quite welcome.
Sorry for your situation.
Someone has to prove the starter needs replacement by being sure the firewall solenoid is operating and passing power to the starter.
The small lead also has to be checked out at the starter for being broken.
It may all be just a coincidence that the starter went into fault.
To remove the starter, there are 3 bolts.
One needs to use a long extension and get to one from the wheel well.
This is why I feel it should be checked out before attempting replacement an not turn out to be the cause for cost and labor.
Good luck.

 

"P1298" doesn't even exist for this vehicle, digits are likely transposed. A valid DTC is needed.

 

[QUOTE=Bluegrass;5228416]You quite welcome.
Sorry for your situation.
Someone has to prove the starter needs replacement by being sure the firewall solenoid is operating and passing power to the starter.
The small lead also has to be checked o
ut at the starter for being broken.
It may all be just a coincidence that the starter went
To remove the starter, there are 3 bolts.
One needs to use a long extension and get to one from the wheel well.
This is why I feel it should be checked out before attempting replacement an not turn out to be the cause for cost and labor.
Good luck.
Thanks again, Bluegrass, will check the solenoid operation and the leads to the starter. Will let you know what the results are. I don't have a garage and it is toe- freezing cold here with ice expected, so it will probably be a while before I do anything. My old bones can't take much cold anymore.
Double checked and code really was P1289.

 

https://www.autocodes.com/p1289_2003_ford_f150.html

 

Thank you, glc
Is there a way to test the wiring harness?