Hello All, this is my first post so hopefully I am doing everything correctly. Anyway, I have a 2001 F250 with a 7.3L and ZF-6 manual transmission. The CEL is continuously on for P0118 (ECT) engine coolant temp out of range high. I read this DTC using an AE with the Ford Advanced Bundle. The instrument cluster gauge for coolant temp works with the needle between C and H when warmed up.

The AE seems to read the (EOT) engine oil temp correctly, but the AE reading for the ECT seems a bit strange. ECT volts always reads 0.00v. ECT temp reads 375 degrees (pegged) until it warms up. Then it will start to read temps that look somewhat reasonable (like 150 degrees IICR). Almost like this is a PCM calculated value and the algorithm changes the scaling.

I believe that this model has temp sensors for EOT and ECT. I believe that both go to the PCM and that the ECT sensor also goes to the instrument cluster gauge. Not sure about that though. I don't have a wiring diagram for a 2001 .

Sorry about the long description. Any ideas on where to look next?

I am counting on the expertise of you all. Thank you.

 

Ok. Let me try something different. Do anyone have the wiring diagrams/schematics for the ECT instrument gauge, ECT sensor, EOT sensor and the PCM for a 2001 F250 4x4 manual transmission that they would be willing to share so I can try to figure this out?
Thank you.

 

These pdf's should be what you're looking for.
ECT wiring.pdf

ECT wiring2.pdf

ECT wiring3.pdf

 

Here is Page 27-10 that you requested.
ECT wiring4.pdf

 

Check out the first diagram. The manuals actually have two sensors, one for the dash (which the auto's also have) and one for the PCM (PCM's on the autos don't read ECT). The one you want to look at should be in the drivers side of the water pump right where the upper hose runs into the pump. IIRC, these sensors have low resistance when cold, and it gets higher as it warms up. Maybe once the sensor warms up some, it starts working.

 

Here is the diagnostic flow chart for code P0118.

DM11 CONTINUOUS MEMORY CODE P0118
DTC P0118 indicates that an ECT circuit out of range high was detected. The DTC was set during normal driving conditions.

open or PWR short in ECT signal circuit
open in signal return circuit
failed ECT sensor
failed/poor connection
failed PCM
Perform KOEO On Demand Self Test.
Is DTC P0118 present?
Yes No
GO to DM3 . GO to DM12 .

DM12 INTERMITTENT CIRCUIT FAILURE CHECK — DTC P0118
Clear continuous DTCs.
Key on, engine off.
Shake and wiggle the electrical harness working from the ECT sensor to the PCM connector.
Re-check continuous DTCs.
Is DTC P0118 present?
Yes No
REPAIR intermittent circuit failure. RESTORE vehicle. CLEAR DTCs and RETEST. GO to DM13 .

DM13 INTERMITTENT ECT SENSOR CHECK
Key on, engine off.
Lightly tap on the ECT sensor to simulate road shock.
Check continuous DTCs.
Is DTC P0118 present?
Yes No
REPLACE faulty ECT sensor. Visually INSPECT ECT harness connector for damaged pins. RESTORE vehicle. CLEAR DTCs and RETEST. Unable to duplicate or identify concern at this time. RESTORE vehicle. CLEAR DTCs.




--------------------------------------------------------------------------------

 

Thank you both so much for the help. I have only been able to find the ECT sensor/sender for the instrument panel dash gauge and not the one for the PCM yet. The one for the dash gauge is on the top of the water pump next to the thermostat and has 2 wires. One yellow/red and one red/white. I am not sure where the one for the PCM is. That is kind of why I was asking for the wining diagrams. I am hoping to trace the wires from the PCM to the sensor. Maybe a picture would help. I'll see if I can take a picture of my water pump and engine compartment when I am looking for it.

Thanks again for your help. This truck is new to me. I am used to my old 1988 IDI. I'll let you know what I find.

 

this is a little off subject but I have a question. Since I bought my truck I had a feeling that the pcm was replaced and may not have been programed right (pulled to see if a chip was installed and found crayon on it reading 2001 f350 typical of a junkyard), but have not had any major probs except pcm int rom error (p0605?) comes on every time I run a KOEO self test.
I have been trying to test the 203* thermostat, but my scanner can not find the ECT only EOT. I do have a 6spd and that is uncommon in this area. I have a snap-on verdict so if the pcm is reading it I should beable to see it.
Anyways do you think this may confirm that the pcm was changed probably from an auto truck (very common in this area)? Second question, would reprogramming work or should I just look into new pcm to be safe?
thanks for any info.

 

To respond to Mr. Finch: A PCM from an auto should work in your manual if it is reprogrammed, from what I have read on this site and others. However, I have no experience with it.

I spent a few minutes last night looking for the ECT sensor that connects to the PCM. I was not able to find it. I may have to try to trace the wores from the PCM to the sensor. I did manage to take a picture of my water pump. It wont let me attach my picture for some reason so I added it to my albumn if anyone wants to take a look.

So where is the ECT sensor that connects to the PCM located on a 2001 F250 7.3L PSD with a manual ZF6? It should have an orange/black wire to pin 37 of the PCM and a grey/red wire to pin 91 of the PCM (I think).

I'll try to spend some more time this weekend looking.

 

oddly enough I am dealing with a similar issue. I havent had what I believe to be accurate ECT readings with AE, like you I have a 6-speed so I believe the ECT should be correct. I am running a 203* t-stat but yesterday on a long drive was seeing ECT temps as high as 250*. Today drove it around with AE hooked up and it went all the way up to 300+ as the oil temp was rising, then it dropped to 0 and climbed back up again till it stabilized around 218*. Just went out and looked at my water pump and could not find a second sending unit. I have a L99 auto here and looked on it also to see if I saw any difference and it did the same thing.


Now my question is this. Is it possible that some 6-speeds came from the factory with this and others did not?

 

Have you confirmed that the replacement PCM is for a manual or auto tranny. Check HERE. Also, there is only one ECT sensor whether it is a manual or auto. Keep reading.

AE is unable to read ECT on an automatic equipped truck so ignore any reading you see for ECT if you have an auto. I have noticed that reading can vary by as much as 300°, if not more, compared to the reading on my aftermarket coolant gauge.

Pin 37 on the PCM for an auto is TFT, Tranny Fluid Temp. See attached PDFs. Notice * is for an auto and ** is for a manual on the PCM pin out.

Also on the Engine Controls PDF there is only one ECT sensor. It says Man Trans Only. From what I can discern looking at the attachments Roland posted the ECT sensor for the autos wires directly to the dash gauge and the ECT sensor for a manual wires to the PCM.

This is all very confusing. But then I am easily confused.

 

After looking at the diagrams again, I agree with you, Robin. There is only one ECT sensor, whether Auto or Manual. They are simply wired differently.

 

Ok this makes a lot more sense now. Ive been having high ECT and I checked it today and it seemed like until the oil temp gets up to a certain point the ECT is completely unreliable. I checked it while the engine was cold this morning, and compared it to the ambient temp as seen by the air intake temp sensor and ECT read 100+ while Air intake read 46, believe me, the air intake sensor was a lot closer to reality.

 

This portion of 7.3 wiring schematics leave a bit to be desired.

This is why I installed an aftermarket coolant temp gauge. I can actually see it in degrees and be able to make an accurate comparison with the AE EOT reading.

 

What brand did you end up going with? I'm assuming that even a cheap-o parts store brand gauge will do the trick for this since all its reading is coolant temp and half the time I probably wont care?