99 v70 xc intermittent no start. how does immobilizer work?

kovi · Post by **kovi** » 29 Jun 2014, 11:35

I have the same 1999 v70 xc as before (for any of you that remember) according to the dealer, it is one of the first cars with the immobilizer. can someone explain to me HOW it immobilizes the car? does it kill the fuel pump? the starter relay? or something else? Out of nowhere, I will get a crank without start. the two times I've had it wehen it happened, I DID have fuel pressure and no spark (that i knew of) car would not even try with starting fluid. NO engine codes came up ro were even in history. weather does not affect it. hot nor cold, damp nor dry. it's as if a gremlin wakes up and feels mischievous. I have checked and replaced various sensors as I tested them and they seemed weak. cam, crank and o2 sensors along with a fuel pump relay. my next inline would be ign switch or maybe a fuel pump? not sure until i get another failure....like chasing a ghost but, anyways. insight on the immobilizer please?

thanks

falconbrother · Post by **falconbrother** » 29 Jun 2014, 19:53

Even though I replaced mine I can't tell you that I know exactly how it works. I had an intermittent no start condition also on my 00 V70. I first suspected that it was a fuel system issue but, ruled that out. I eventually replaced the sensor ring and the problem went away. But, first thing this am I hit the starter and it did that spin over no start thing. I gave it a second and it fired right up. It didn't do it again the rest of the day. No codes. So, I am at a loss on these things. I do think that the most likely issue is related in some fashion to the immobilizer.

Post by **abscate** » 30 Jun 2014, 03:58

I believe in that model year the immobilizer interfaces with the ECU and inhibits ignition. The engine will crank fine but not fire.

kovi · Post by **kovi** » 25 Jul 2014, 15:06

thanks for the insight.... the car went a whole month without an issue and now *poof* there it is again. just for the giggles of it.... I closed up all the doors, locked the car.... opened the car, put the key in and ...you guessed it...*poof again* started right up.

Post by **abscate** » 25 Jul 2014, 18:59

I'm not positive that is correct but I'll do done searching and try to verify