Hey guys, need some help have a Mk1 1.4TDI 05 plate Fabia, replaced the Engine Coolant Temperature sensor as have got code P0118 after replacing it and clearing code still have got the code, ran the engine and am getting a correct temp reading though the OBD2 port and on the dash, the wiring is good at the plug but did a voltage test on the plug and came up at 0.62 something volts anyone have any ideas what could be causing the code P0118 still??

Was it a genuine CTS? Spurious ones aren't great. I bought "genuine" ones off a well known auction site and they weren't. 

Unplug it, clear the code and see if the code returns with the CTS unplugged or if it changes to a different code.

So tried unplugging it and clearing the code and still comes back, with or worth out but the temperature doesn't drop or rise of unplugged at all. And yes it's an genuine part as well

Also tested the CTS before putting it in and it was in the correct ranges when ether at room temp or in a glass of hot/near boiling temp water

Maybe examine the connections at the engine ECU ends of the wiring, and measure the resistance of each wire. Pins 104, 112 at the 40-way connector.

And maybe look at the loom run between engine and there, looking for any signs of damage.  Wondering if an intermittent short to some other random wire might be responsible.

 

Edited 24 February, 20215 yr by Wino

Can you able to post a picture of the pins please to make sure I'll be getting the right ones.

So after testing the pins 112 that's at 5v and pin 104 is at 0

It was the wires you were supposed to be checking, for low resistance between ECU connector and sensor connector; and, by visual inspection, for not having any short-circuits to any other wires.  ECUs are very reliable, so I wouldn't expect any problem within that.

The connectors on both ends are in good condition no sing of damage but had to stop there for the time being as had to get stuff sorted out in the house