Df115a IAT sensor issues

[Spanks]

Sorry if this has been posted before. New to forum and couldnt find anything when searching.
I am getting fault code for IAT sensor. I checked wires, one was broken so solder and it went away for a few trips but now back again. I have replaced pins into connector plug but alarm still there. Checked volts to plug but not getting 4v. Is it worth replacing the sensor? Anything else I could try?
Do these sensors alarm with voltage spikes?

[Spanks]

It's 2013 df115a

[Murray]

If your not getting 4V at the plug you have an issue with the wiring.

[Spanks]

Murray does that generally result in needing a new harness?

[Murray]

Find the issue first then evaluate. Electrical isn’t my strong suit but depending upon what’s happening I don’t see why it couldn’t be fixed. Reading up on my service manual worst case scenario could be an issue with your ECM but faulty ECM complaints on this forum are rare so I’d be going over the wires that feed the IAT with a fine tooth comb.

[redlowrey]

Murray is on the right track, the computer sends five volts down the iat wiring and through the iat sensor back to sensor ground at the computer, depending on the the resistance of the sensor will determine what the sensor voltage will be. With the plug disconnected with the key on, the open circuit voltage will be over four volts but less than five.
I wouldn't think that the problem was more than three inches away from the connector, with the key on connect your volt meter up and get a thin needle to penitrate the cable, go about four inches from the harness connector and check if you have voltage if you do come forward and do the same thing until you don't, that will be here the break is. Solder in a new wire job done.

If you don't find voltage on the wire back from the connector, you will have to do some detective work between the ecu and the iat connector, but I am reasonably confident you will find the break close the the connector.

[Spanks]

Great. Have done volt test at IAT plug and nothing. Thank you. Will see if I can have a go at it. Wires are really tucked and hard to get at in places.

[Spanks]

Thanks Red, Question. Do you need the special tools 18 & 32 pin test cord mentioned in the service manual to check for resistance of IAT sensor?

[redlowrey]

The only thing you need to fix this problem is a volt meter, worry about the sensor side of the plug when you have found your five volt reference voltage on the harness side of the plug. I think when you find the break in the wire and repair it, the problem will be over.
Just make sure when you connect your meter up, you test the positive probe on a known voltage to make sure your meter ground is ok.

Mate this should be easy for you to find, you don't have to have a lot of electrical knowledge, if you get into trouble trying to find the break just come back on the forum and I will point yo in the right direction.

[Spanks]

Cheers Red. I was jumping ahead.
It could be difficult to find the break as wires are in a loom going up through motor but I will start at the easy to get to places near the connector. Thanks for your help.