IAT wiring fault/break in line

[Mart7379]

After replacing the Intake Air Temp sensor, and still getting a reading of -40c, which someone in my previous post suggested it being a open circuit.

I did a little more digging and beleive I have found the issue/broken wire in this T Junction (best way to describe) as, when I wiggle it around the temp fluctuates. However I can't pull it out far enough to be able to access and repair what I suspect to be a broken wire.

Is it possible to pull enlugh of the loom out to gain access to effected area, am i roght in thinking the plug on the left has a similar sort of lock as to the 1 going into the IAT/Map sensor, has anyone managed to fix a broken circuit on this particular part/sensor

[RichardW]

It should just be taped up poly loom, cut the tape off and you should be able to pull the corrugated stuff back to expose the wires

[Mart7379]

Ok, I'm assuming it can all be detected from the brackets allowing me to pull it out far enough. For obvious reasons I do not want to start disconnecting more than needed

[andyandjulie]

Hi

It looks like you could detach both of the plugs (they'll have tabs that you'll need to release), pull the wiring from that U clip and have plenty of slack to find the break once you've got rid of the tape and plastic sleeving stuff. I'd use heat shrink and a soldering iron. Well spotted!

Andy

[Mart7379]

Yeh there is barely any slack at the moment. Actually found the problem area by accident as i was convinced it was the IAT sensor.

Was planning on sorting it today, but it has rained all day!!!!!

(In case anyone is wondering, the pic of the engine is from a picture i found online of an extracted engine)

[andyandjulie]

Hi Mart

It's rained all day here in Wales too, depressing, at least it's not cold now lol.

It could be a pin in the connector has moved relative to the connector if that makes sense. Perhaps to start with just unplug and replug the connectors? Failing that, look for any obvious problem, use a pointed probe multi-meter to test continuity. It won't be that hard to find the break..

Andy

[Mart7379]

Yeh my 1st point of call is to check the connection in the plug, i spoke to a Citroen specialist a couple of days ago who stated its a common problem for the plug/connection to become too far apart. (I hope that makes sense)

I'm not all that clued up with multimeter and after researching what setting to do a continuity test....... makes a sound when I put the 2 probes together......... anyway, just playing around, i popped the probe into each of the holes in the plug, and touched a metal part of the car (engine mount to be precise) 1 of the 4 gave a sound. As stated, could be the connection is not connecting..........

[Mart7379]

Little bit of an update, and maybe a opinion.

I may have inadvertently found the issue. And it was niggling at me. Yesterday I was trying to figure out what the problem was with the car, EML and IAT sensor.

A couple of months ago, the car had a burnt out connector on the heaters. (Pics attached) pins had burnt out/melted, which i repaired by cutting the old connector plug off, and repairing with butt connectors, ?i think 5 amp capacity).

After speaking to an auto sparky, he suggested it could be something totally unrelated to the IAT sensor, with that in mind and the burnt out connector, then replacing with 5amp connectors it MIGHT have been the cause. -40c can mean open circuit but it can also mean, the volt is over 5amp, I turned everything related to heating/blowers off!

EML deleted and didn't return until my wife turned on the rear window heaters....... EML came on..........

Could the possible problem actually be the 5amp butt connectors are not restricting the amp/volts in the loom.

[PaulC5]

Those wires look a lot thicker than 5 amp rating, you might want to join them with something more substantial than 5 amp spade connectors. Soldering or a terminal strip might be better. With the connector burning out before it shows the amps carried by it are probably high.

[Mart7379]

The wires in this particular are different diameters, I couldn't quire understand as to why. Although beleived the route cause of the burn out was due to the thicker wire.

I'm in London this weekend with work, but off Monday, so will strip it back and put a different connector on. I'm guessing becasue the butt connectors are a max 5amp. The wiring might be sending over 5amp and becasue this connection can't cope, it's sending it somewhere else. On this occasion to the IAT sensor.

Could you recommend a particular connector? Id just solder but I've never neen any good at it.

[PaulC5]

You could try a terminal strip similar to this but you could disconnect the spade ones and see what happens with the IAT. https://www.screwfix.com/p/essentials-1 ... pack/91532 You could do with finding out the fuse rating for whatever the wires are supplying to make sure you get a connector with sufficient rating.

[Mart7379]

Ok, tried the electrical circuit but also came to the conclusion that if the vote was too high for the connection, it would of blown the fuse??

EML, has returned! However, if I pull or wiggle the wires around going into the plug of the MAF sensor, the temp fluctuates from -40 to around 15-20c. If I pull the wiring slightly it'll stay at 15-20c

Faulty MAF sensor or plug?. If plug, are replacements readily available.