Hi everyone,

im in need of some help!!

I have a 2016 focus 1.0L ecoboost, the engine light has been coming on.

A code read came up with p0036 which is the post cat sensor heater circuit. Being lazy I just swapped it for a new sensor and low and behold the light came back on after driving.

looking further into it I checked the power and earth going to the sensor which(when the car is stationary) were fine.

checked the resistance on the new sensor which was also good.

I then ran a new signal wire from the ecu and a live wire from the sensor fuse just incase there was a break in the original wiring which would only produce the fault when driving.

unfortunately the light is still coming on..

am i looking at a ecu fault??

any help would be greatly appreciated,

many thanks in advance. 

Jer.....

Hi having the exact same problem as you are with the 1.0 eco boost. Did you solve your problem ? Many thanks

On 4/22/2021 at 6:53 AM, Dan489 said:

Hi having the exact same problem as you are with the 1.0 eco boost. Did you solve your problem ? Many thanks

Still no joy my end. Thinking it’s the ecu but don’t want to spend money getting it tested before I’m certain that everything else is okay.😞

Hi, I have the same issue, replaced the sensor but still the engine management light came back after driving. Did anyone managed to find cure. Thanks

 

Did you clear the codes after fitting the new sensor?

Hello.  I have same problem with my focus 1.0 ecoboost ( from USA ) . I 've cleared codes after replacing sensor. But error still present. 

can someone share pin description  of o2 sensor connector.? 

Thank you 

Hi guys did anyone ever get to the bottom of this? im having the exact same issue,

 

thanks

Could possibly the the cat itself is at fault, if the emissions are incorrect, the light will come on, but usually there will be a cat fault code, but not always, although it’s an expensive thing to change, especially it it doesn’t fix the fault, have you tried cleaning all the other emission related sensors also, maf, map, temperature and so on?

Hi mate, thanks for your input,  yes I’ve had a look at most of the other sensors and have had the emissions tested which are good. the fault code actually says heater control circuit, so I don’t think it’s to do with the actual emissions, but can’t find any problems with the circuit, fault will clear but come back on after a short amount of time 

I suspect you either have a dirty/blocking up cat (try a good cat cleaning additive for your fuel like CATACLEAN) or a faulty lambda heater circuit relay.

On 4/22/2021 at 7:53 AM, Dan489 said:

Hi having the exact same problem as you are with the 1.0 eco boost. Did you solve your problem ? Many thanks

 Have you solved the problem? I replaced the sensor and after a week the error code P0036 appeared

Been having the same issue with my 1.0 138bhp red edition 2015, it started a while back it’s a straight through exhaust and was knocking the car into limp mode. It’s not driving in nothing but limp mode, no boost at all so very slow on getting out of junctions. Anything I can do?

Put a proper exhaust back on. 

Is it de-cat as well?  Straight through cat-back should be fine for lambda readings.

If it's de-cat you'll need the second lambda mapped out.