Electrics: Proud new owner of an S80, some questions

[Nightstalker1993]

Hi guys, greetings from Malaysia. I had just recently purchased a Volvo S80 year 2000 2.0T with a B5204T5 engine from a friend who was the 2nd owner, I am now the 3rd owner. The car is a genuine low mileage unit with only 71k km on the clock. So far it had been a dream to drive but I had encountered some issues which are quite mysterious which reduces my confidence in the car for driving long distance. First of all, I do not have access to a VIDA/DICE unit but I do have access to a Launch scantool from a workshop friend, and the car is clear of fault codes, other than an Audio Module(AUM) Missing code which is most probably due to the stock HU being swapped out to an Android unit. I am new to Volvo and basically Euro cars, but am pretty well versed in the mechanics of cars in general.

Occasionally, out of complete random, it might take a longer time to start the engine, 3-5 seconds of cranking, and when it does start up, the engine is clearly misfiring with the exhaust smelling like unburnt fuel for around 10-20 seconds and the engine will smoothen out, then it behaves like nothing ever happened. No error codes, nothing. After it had smoothened out, everything is like normal, power is good and no misfiring at all. The frequency of this issue occuring is really random, at times it does that on the first start in the morning after a few days without starting, other times it does it with the engine fully warmed up, I stop at a petrol pump to fuel up and the subsequent start it happens. So far this is still bearable as the engine still performs like a dream and it rarely happens.

Just a few days ago, the car mysteriously refused to start, no crank, nothing. Just absolute nothingness when I turn the key. I can confirm the starter solenoid isn't even clicking as there is no voltage drop/lights dimming or sound from the engine when I turn the key. Certain attempts to start the car brought up a warning message saying 'Immobilizer See Manual' after around 30 seconds of attempting to crank the engine without turning off the ignition. I then started ruling out all of the major suspects, checked the antenna ring, it was good, tried jump starting eventhough the battery voltage was more than enough, still refused to start, checked the starter solenoid connector also good, gave the starter a couple of decent knocks, still nothing. Totally stumped, I tried disconnecting and reconnecting the battery, after 30 seconds of that I tried cranking and again, nothing happens. I was prepared to give up and went on tightening back the battery covers, after that is done, I tried cranking it again and lo and behold, the engine turned over and started without issues. After that, the engine had never failed to turn over so far, it had been 3 days since the incident and had probably started the engine around 20 times in that period.

I am just worried this issue might come back again as I cannot find the true source of this problem. It does seem like the computers are preventing the engine from being started for some unknown reason. I don't think it is the immobilizer as the message only came out like 30 seconds of turning the key, not immediately.

Another question I have is that the cruise control does not work. I understand the music control does not work as it is now running an aftermarket Android head unit, but the cruise control also does not work makes me kinda sad. Viewing live data with the Launch tool, the car does not seem to register the button presses, no response at all. Or is this really related to the head unit being missing?

Thanks guys, look forward to my ownership of this beauty of a car.

[reggit]

The immobiliser message means the car hasn’t ‘seen’ the chip in the key. Suggests the antenna ring may have been at fault. May just be a one off though.

Cruise, if car is a manual, push the clutch in and press cruise. Does the word ‘cruise’ appear on the dash? If so let clutch up, if it goes out the clutch switch is faulty.

[Nightstalker1993]

Originally Posted by reggit

The immobiliser message means the car hasn’t ‘seen’ the chip in the key. Suggests the antenna ring may have been at fault. May just be a one off though.

Cruise, if car is a manual, push the clutch in and press cruise. Does the word ‘cruise’ appear on the dash? If so let clutch up, if it goes out the clutch switch is faulty.

Thanks for the quick reply. I don't think it's the immobilizer as I tried with the antenna disconnected, it gave a different error message 'start inhibited, please try again' immediately when I try to turn the key. In my case it came out after 30 seconds of turning the key furiously.

The car is an automatic. The issue seems to be the car doesn't seem to be receiving the button press signals from the steering wheel buttons as the live data shows that.

[cheshired5]

Have you tested the coolant temperature sensor?

[Nightstalker1993]

Originally Posted by cheshired5

Have you tested the coolant temperature sensor?

I'm not too sure how that contributes to my problem, but it should be working, my Ultragauge shows no problem with the coolant temp readings.

[jgjones095]

On a side question, what android head unit is that?

[savabill]

If your brake position sensor was faulty could cause your cruise control to stop working, but I would have thought that you would have had a code for that. Might be worth checking the connectors for loose wires etc.

[Dippydog]

Just a random thought,but as an auto could the none cranking issue have been down to the gearbox inhibitor switch?As in it not "telling" everything else the car was in park or neutral because this would prevent the starter from working.Like I say just a random thought but you never know

[Nightstalker1993]

Originally Posted by reggit

The immobiliser message means the car hasn’t ‘seen’ the chip in the key. Suggests the antenna ring may have been at fault. May just be a one off though.

Cruise, if car is a manual, push the clutch in and press cruise. Does the word ‘cruise’ appear on the dash? If so let clutch up, if it goes out the clutch switch is faulty.

Add on: From what I read while Googling online, apparently the Immobilizer message will come up if the car wouldn't start for any other reason I think. I remember someone mentioning when his starter failed, that message popped up as well.

Originally Posted by jgjones095

On a side question, what android head unit is that?

I am not too sure the exact model as the previous owner installed it, but it seems to be a PX-3 and you just have to type in Android S80 on AliExpress and you'd be spoilt for choices! I think the newer model is the PX-5.

Originally Posted by savabill

If your brake position sensor was faulty could cause your cruise control to stop working, but I would have thought that you would have had a code for that. Might be worth checking the connectors for loose wires etc.

I doubt it is that as well. Brake lights works fine and as I mentioned, viewing live data through the OBD with a Launch scan tool indicated that the car isn't receiving any information on the button presses. Is the cruise control buttons linked to the AUM as well?

Originally Posted by Dippydog

Just a random thought,but as an auto could the none cranking issue have been down to the gearbox inhibitor switch?As in it not "telling" everything else the car was in park or neutral because this would prevent the starter from working.Like I say just a random thought but you never know

Yes that was also a suspect as the previous owner had told me there is occasionally this issue as well, I encountered it a couple of times before too I think, but usually when that happens I just have to shift it to D and back to P and it will start right up. Also is the gearbox inhibitor switch a separate sensor with the gear shifter sensor? As you can see in my image above, when the Immobilizer message is out, the indicated gear position clearly shows 'P'