Hi I have an issue with the CHT sensor on my 1.0 ecoboost Fiesta. I have checked the supply (5V) at the connector end to the sensor and I have no voltage at all, Does anyone know where I can pick up the connections at the supply point so that I can check continuity to see if there are any breaks in the cable.  Does anyone know what other sensors might be in line with the CHT supply. The fault codes I have are

P1023 cylinder head overtemperature sensor 2 high temperature.

P1299 cylinder head over temperature protection active.

P1299 cylinder head overtemperature sensor 2 circuit high. 

Any assistance would be appreciated as the car is in limp mode and is undrivable.

Thanks

The CHT shares its 5 v Ref with the engine coolant temp sensor thats above the gearbox. Does you engine temp dash gauge work ? 

If you have access to a multi meter I could measure the resistance of my sensor on a cold engine for you to use as a comparison? 

Below is a table of sensor resistance / voltages which might help. The values should be +or- 5%

 

Hi Both thanks for your assistance and offer of help. What happens is I switch on the ignition and start the car which idles for a second or two then will not rev and the engine goes lumpy (limp mode I assume). I do not know if the temp gauge works as I start the car from cold so the gauge hasnt had time to register.  I will check the gearbox sensor as I have a Fluke multimeter. 

To update you I now have 5V I have also recored about 3.75V as well at the CHT sensor connector block but still have the same issue.

1.5. P053F:21-48 Cold Start Fuel Pressure Performance Bank 1 CMDTCs 1.6. P1023:00-AF Cylinder Head Temperature Sensor 2 Circuit High CMDTCs 1.7. P1285:00-2F Cylinder Head Overtemperature Condition CMDTCs 1.8. P1299:00-AF Cylinder Head Overtemperature Protection Active 2.1. B10EA:00-48 Positive temperature coefficient heater CMDTC

Thanks again

have a similar problem on my focus.  1.0L  coolat temp is 192 but i get the p1299 and engine goes into reduced power .  engine is not overheating.  Brush did you ever get yours fixed

20 hours ago, butter said:

coolat temp is 192

I assume that is 192 degrees Fahrenheit or you have bigger problems than just a hot engine

Replace the the temperature sensor. The DTC P1299 will cause the engine to go in to limp mode as it thinks the engine is over heating.

On 12/22/2021 at 3:38 PM, unofix said:

I assume that is 192 degrees Fahrenheit or you have bigger problems than just a hot engine

Replace the the temperature sensor. The DTC P1299 will cause the engine to go in to limp mode as it thinks the engine is over heating.

Replaced that part from ford and all other coolant parts .  No help.  Took to ford .  They don’t even know why

Did you ever get this problem resolved? I have three 1.0 ecoboost vans all doing the exact same thing as yours, comparing the live data for coolant temp, cylinder head temp and oil temp they seem to rise quicker than a van without the issue. 
i had the RAC come out to one of these and he said they suffer with oil leaks ng through a sensor into the loom which causes this fault, has anyone else experienced this? If so where is the oil temp sensor?

12 minutes ago, HVS said:

Did you ever get this problem resolved?

Don't expect an answer. They were last here 21st Jan 2022

12 hours ago, HVS said:

Did you ever get this problem resolved? I have three 1.0 ecoboost vans all doing the exact same thing as yours, comparing the live data for coolant temp, cylinder head temp and oil temp they seem to rise quicker than a van without the issue. 
i had the RAC come out to one of these and he said they suffer with oil leaks ng through a sensor into the loom which causes this fault, has anyone else experienced this? If so where is the oil temp sensor?

Oil penetrates the loom through the cam sensors or the VCT actuators on the 1.0EB.

I'm not sure these have an oil temp sensor.  It may just be a calculated value using coolant temp and head temp.  Are they the wetbelt version or chain version?

2 hours ago, TomsFocus said:

Oil penetrates the loom through the cam sensors or the VCT actuators on the 1.0EB.

I'm not sure these have an oil temp sensor.  It may just be a calculated value using coolant temp and head temp.  Are they the wetbelt version or chain 

2 hours ago, TomsFocus said:

Oil penetrates the loom through the cam sensors or the VCT actuators on the 1.0EB.

I'm not sure these have an oil temp sensor.  It may just be a calculated value using coolant temp and head temp.  Are they the wetbelt version or chain version?

Thanks for the advice, I’ll take a look now, this is the chain version