Greetings, I have an old 2007 C2 1.4 TDI, VIN VF7**************[VIN obfuscated, can be read by forum staff]. We've rebuilt the engine over the past month, changed a lot of stuff and managed to fix most of the problems, however the last one still persists - the engine overheats. While trying to solve this we managed to realize that the ECT sensor isn't actually connected to the ECU, but gets 12V(instead of 5 or maybe even 2) from somewhere, meaning that someone tried 'fixing' this car before us and failed miserably.
Two ECT sensors are already dead(no resistance could be measured), however the ECU still thinks the coolant temp is around 28 degrees C nearly all the time, even when the engine intake temp is above 60C.
We suspect there is some kind of static resistance connected to the ECU somewhere in the loom, but getting the engine out for the fifth time and unwrapping the whole loom because of it sounds a bit excessive, so we decided to make a shortcut and just connect the sensor directly to ECU, we just need to know what pins it should be connected to.
Please share the electrical scheme if you have one for this car, we could only find the ones for other models/engines online and they don't seem to fit.
Thanks in advance.
C2 1.4 TDI overheating issues
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GiveMeABreak
- (Donor 2016)
- Posts: 41989
- Joined: 15 Sep 2015, 19:38
- x 6958
Re: C2 1.4 TDI overheating issues
I've deleted your other post - please don't duplicate posts for the same issue. You'll just have to be patient until somebody has the time to help - with hundreds of posts a day we can't always get round to everyone as quickly as they'd like!
Now that I've seen your post, I may be able to help.
Here is the cooling circuit for you:
With the exception of the wiring codes, most of the component codes are indexed here:
PSA Electrical Diagrams - Wiring & Symbols Codes Index
Cooling

Engine ECU

Now that I've seen your post, I may be able to help.
Here is the cooling circuit for you:
With the exception of the wiring codes, most of the component codes are indexed here:
PSA Electrical Diagrams - Wiring & Symbols Codes Index
Cooling
Engine ECU
Please note, I'm no longer active on the Forum, so won't respond to messages.
Marc
Marc
-
Zalupov
- Posts: 2
- Joined: 26 Jun 2024, 21:41
Re: C2 1.4 TDI overheating issues
Thanks for the schemes!
Found the static resistance as previously assumed Repinned new wires directly to the sensor and now everything works as intended, the car didn't overheat even with 36? outside while we were stuck in a jam for half an hour.
Found the static resistance as previously assumed Repinned new wires directly to the sensor and now everything works as intended, the car didn't overheat even with 36? outside while we were stuck in a jam for half an hour.