Hi Guys,

 

Got my Fabia VRS a little while ago and it had the EML on.  Couple of days ago had a look with the fault code reader and got the (apparently common) 17571 fuel temp sensor short to +ve / open error.

 

Had a check of the sensor and it seemed fine, had a check of the wiring physically and performed a continuity test over the short length that sticks out the main loom and its fine too.

 

Bought a new sensor and popped it on tonight...and the error keeps coming back.

 

So before I go opening up the whole wiring loom and checking the wire physically and electrically over its full length...is their anyway possible the map on the car the now (non standard map) could be causing the issue?

 

Turned the ignition on and have 0V between the 2 connector pins on the loom and 0V between either pin and -ve on the battery.

So as far as I can work out, the ECU either has a software or hardware error with it...or the +ve wire to the sensor has a break in it somewhere...but not in the little bit of wire that sticks out the main loom :(

 

Thanks in advance for any help!

The sensor will be roughly 4k-6k in this kind of weather. There are no intermediate connectors, so the only check you can do is wiring continuity to the smaller ECU connector (pin 1 -> pin 103, pin 2 -> pin).

Yeah thats the range I had for the sensor, chucked it in a cup of hot water later on last night and the value dropped away to a couple of hundred ohms as expected.

 

As for the continuity checks I used the old pikey method of making a very tiny nick in the insulation and checking the continuity from that point to the temp sensor connector, then potting and taping back up the nick.  Portion I checked last night was fine.

 

My next question was what is the ecu pinout but youve already beat me too i haha!

 

Thanks for the help

 

Will report back with any findings

Quick Update.

 

This afternoon checked the wiring at the ecu end, pins 111 (green wire) and 103 (brown wire).

 

Brown (-ve) is totally fine and when the ignition is on shows continuity with -ve on the battery (as expected).

 

Green wire on the other hand has a break in it somewhere inbetween the temp sensor and the ecu connector...

...seeing as they are a twisted pair all the way through the loom and bound with tape it wont be quite as simple as cutting one end of the existing wire, and puling a new length of wire through using the old wire...

so will either open up the whole loom and find the break and repair it...or connect up a new length of wire and try find a semi decent route for it!

 

Thanks rwbaldwin for the help with what ecu pin to start looking at

If you unwrap the loom then rewrap it with Tesa tape. You might find it easier to buy a length of CAN-Bus twisted pair and replace both wires. Then you can tape the twisted pair to the outside of the loom.