CHT Sensor (Clyinder Head Temperature) - Ranger-Forums - The Ultimate Ford Ranger Resource

General Ford Ranger Discussion General discussion of the Ford Ranger that does not fit in any other sub-forum.

LinkBack Thread Tools Search this Thread
Old 02-15-2012
Thread Starter
Join Date: Jan 2009
Location: Jacksonville, FL
Posts: 4
CHT Sensor (Clyinder Head Temperature)

I have a 2003 Ranger with a 2.3L engine. While running I got a check engine light with temp gauge in the intrument cluster going full hot. I checked and got a P1299 code. This indicated the CHT sensor was in protection mode. The actual coolant temperature was not overheated when I checked and later when I started the engine in a cold condition the code threw again with the temperature gauge going full Hot (when it was absolutely cold). OK, so I will replace the CHT, I believe since it was in protection mode it was giving the computer the wrong fuel mix causing my engine to run rough also. I unplugged the CHT (until I install the new CHT) and the engine runs OK with a new P1280 code (expected since the CHT is unplugged) and the temp gauge inside is dead with no input and needle below the C position.

There are two sensors, one is the mentioned CHT sensor and the other is the ECT (Engine Coolant Temperature) sensor. The CHT signal goes to the computer and the ECT is supposed to supply the signal to the temp gauge on the instrument cluster.

Question 1 (Important): Does anyone know the correct torque setting for installing the CHT? I know it is a low setting because you can break off the threaded portion due to it being thin brass.

Question 2: Why was the temp gauge reading full hot as if the signal to it was coming from the CHT instead of the ECT sensor? The temp gauge signal is supposed to be coming from the ECT.

Question 3: Does the CHT override the ECT input to the temp gauge when it thinks the coolant is too hot?

Question 4: After I unplugged the CHT I got no temp gauge reading. Is this a condition of the possible override (question 3) or do I have a bad ECT also? Note: I got not codes relating to ECT.

I would appreciate any comments that help clarify this.


Last edited by jaustin175; 02-15-2012 at 07:39 PM. Reason: fix errors
Reply With Quote

Related Topics
Thread Thread Starter Forum Replies Last Post
CHT Sensor (Cylinder Head Temperature) Problems jaustin175 General Technical & Electrical 5 12-13-2015 12:13 PM
2005 4.0 temperature sensor mark gezon Member Introductions 0 12-14-2013 11:35 AM
Removing coolant temperature sensor on a 1993 3.0 V6 pw2buz 2.9L & 3.0L V6 Tech 0 06-21-2012 06:55 PM
Pictures of where the Engine Coolant Temperature Sensor & Sensor LOCATION? Liquidswords32 General Technical & Electrical 3 03-26-2011 02:47 PM
Want to Buy: temperature sensor for OHC Tys 4x4 FTW Interior, Exterior, Electrical, & Misc. 4 03-20-2010 01:05 AM

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

All times are GMT -6. The time now is 06:49 PM.

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliated sites.