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Check engine light - P007B

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6
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3
Location
Warsaw, Poland
#1
Hi! I got P007B error code for a few times now. It's showing up only when it's quite cold or warm outside (under ~-5 celcius or over ~30 celcius). I know that it's related with charged air temperature but I cannot find what is causing this problem. I replaced MAP sensor few months ago but I still got check engine light recently when it got cold outside. Is it the wrong sensor to check or maybe it's somehow broken down again already? The car - Fiesta ST MK7 2016 USA.
 


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Location
Boston
#2
Do you have a tune or aftermarket intercooler? Did you buy the car new/used? What's the P/N of the sensor you bought? And which sensor did you replace? the one on the pipe or the one on the manifold?
 


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OP
pop_92
Messages
6
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Location
Warsaw, Poland
Thread Starter #3
Just stock IC and no custom tune, BUT you reminded me that my IC is has slight dent from underneath. Could this be a reason? CEL is only showing up during cold start btw.
 


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487
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422
Location
Boston
#4
I would check the TMAP sensor and wiring that's located on the cold side charge pipe first. If that dent is causing the code, I'd expect some drivability issues.
 


OP
pop_92
Messages
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Location
Warsaw, Poland
Thread Starter #5
The original part number of MAP sensor was bv61-9f479-aa. It was located on the cold side charge pipe as you said.
 


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Location
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#6
Def follow the wiring and electrical diag for that sensor if you can, then the next thing might be that dent in the intercooler
 


OP
pop_92
Messages
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Location
Warsaw, Poland
Thread Starter #7
But why would CEL only show up in this specific scenario if its some wiring issue? I will try it anyway when I have some spare time. Also this would be good excuse to change stock intercooler :unsure:
 


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Location
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#8
But why would CEL only show up in this specific scenario if its some wiring issue? I will try it anyway when I have some spare time. Also this would be good excuse to change stock intercooler :unsure:
No idea, but it's a free to do check, it just takes some time, it I feel it's worth it to check that before throwing money at parts. But if you're eyeing an intercooler anyways, go for that
 


OP
pop_92
Messages
6
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Location
Warsaw, Poland
Thread Starter #11
OMG I think I found it... You guys were so damn right about wires. Previous owner fixed wiring harness insead of replacing it so because of that charge air cooler temperature and TMAF temperature wires were swapped. I hope it was only those 2 :D

IMG_20201219_191534.jpg IMG_20201219_201313.jpg


Thank you all for help!
 


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422
Location
Boston
#12
Glad you found the issue! The outdoor temperature may have been just a coincidence or those swapped sensors might have sent a signal that was within range during those temperatures. Maybe replace the wiring harness too.

Some unsolicited advice/info for those that may be curious: sensor "out of range" codes typically are sensor failure or wiring failures.
Sensors have a signal range that align with a measurement reading. Signal could be 0.5-5V, 4-20mA, 0-1kohms etc, etc. Your ECU knows that a working sensor physically can't report values below or above that range, so if receives a signal below or above the sensor's max range, it lights up the CEL saying "I'm getting signals that I shouldn't be" or "I'm not getting a signal".

It also looks at other sensors to double check if a sensor is reading close to what it expects. For example: you're wide open throttle, the car is reading lots of air flow, your other MAP sensor is reporting boost, but your ECU is reading vacuum from that TMAP sensor. You're car will light up the CEL saying "hey man, at 100% open throttle, with lots of air flow, my other pressure sensor says 25psi, that vacuum reading is physically impossible".

I suspect the second part was happening here as the sensors were mixed up, perhaps they were sending signals that the ECU thought was okay at the time by coincidence
 


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