2008 XC-70 Periodic starting issue - weird!

stheemka · Post by **stheemka** » 18 Feb 2023, 07:44

Last fall, my 2008 XC-70 developed a weird intermittent start issue. Most of the time, you get in, insert the key fob, depress the brake and then the start button, and it starts no problem. But a couple of times last fall, for no reason we can detect, when you did all this and then press the start button, you just got a click, then some flashing of various indicators, "interlock" being one of them, and the starter never turns over. Just a click and the instruments kind of go crazy. Sometimes you could click it again and take out the fob, and sometimes you click it again and still nothing, but it won't release the fob. It is like some part of the car thinks it is running or something. We also get a rotten egg small, so maybe the fuel system is operating somehow too while this is going on?

We thought for a while that it was the key fob (one worked and the other didn't, it seemed like) so we changed the batteries in both, and while it was fine for a week or two, it then had this issue once or twice more.

Then all seemed fine through the winter until this past week, when it happened again. Put the key in, and everything goes haywire. Here is a video:https://photos.app.goo.gl/LCukaCCptF2tPD1w9

Any ideas for even where to start? Thanks!
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Post by **Krons** » 18 Feb 2023, 08:41

What codes do you have?

Post by **Krons** » 18 Feb 2023, 08:41

What codes do you have?

stheemka · Post by **stheemka** » 19 Feb 2023, 09:28

I have not taken it in yet, so have don't have any codes.

lazykiller · Post by **lazykiller** » 23 Feb 2023, 11:12

I would take a look at the inline fuse on the positive battery cable going towards the starter.
I diagnosed my car having a physical crack on it, it would randomly start and took a while to figure out.
Similar behaviour from what I remember seeing.

Should look something like part number 31343764.

Post by **pgill** » 24 Feb 2023, 09:54

I agree that a bad power connection could be the cause of the fault.

Here is what I would do

1. Open the fuse box in the engine compartment and attach a volt meter between Battery (-) and the 12 Volt power at the point of entry. Confirm that you have 12 Volts.
Then have someone try to start what does the voltage do? (Drops slightly 12.6 to 11.9 or Drops significantly 12.6 to 5.0.)
A significant drop is either the fuse mentioned above or a broken starter motor.

2. If the Voltage at the point of entry for the fuse box is good then you need to look down stream. (A Fuse, A Relay, A Bad Ground)

Let us know what you find

Thanks

Paul