FIXED: Odd festive no-start (Immo and DSTC)

[foggyjames]

Happy Christmas, all!

Went to get in the car earlier, to be presented with some odd behaviour:
1) No crank, and "Immobiliser - Try Again" (or similar) message
2) "DSTC Service Required" (or similar) message on dash
3) No external temperature display
...and I think possibly another module warning one time, and the ABL-disabled light was also on at one point.

I am away from home, and don't have my VIDA kit (or anything useful like a multimeter) with me.

Prior experience suggests that the first port of call with a load of weird faults like this is to see if the battery is flat. The battery is old, but the car is used extensively, so I wouldn't expect there to be problems, and I haven't seen a Low Battery warning in months. I just tried a jump start, which didn't work.

Given that I have limited options for sorting it out myself (being away from home, etc), and that I need to be on the road in a couple of days, I may well need to hand it over to professionals sooner rather than later. In the meantime, though, anyone got any ideas? I might have a crack at cleaning the CEM contacts tomorrow. Does it live behind the glovebox?

cheers

James

[Peter2400]

I'd try battery first. Even if used regularly, it can just suddenly die without any sign, especially if it is old. Happened to me, moreover it was in the summer. I was using the car, shopping, etc then parked, the next day was just dead, all sorts of fault messages like your's. No low battery message prior to it too, nothing. I bought a new battery and then first just connected it via jumper cables. No fault messages, everything worked, except when i tried to start it, it just clicked but didnt start. Tested the new battery, voltage was ok. But before thinking of further investigations, i decided to put it in place and give it a try. Started instantly. What i can think of is the connection of the jumper cable (or the cable itself) just couldn't transfer enough current to start the engine.
Sorry for long post, maybe someone find it useful, but in a nutshell, try with the simplest thing, in this case, the battery. Also test the alternator while your at it.

[foggyjames]

Thanks for your thoughts. Does your car have start/stop and an AGM main battery? I’m in two minds re: battery being at fault.

On the one hand, it’s what sprung to mind straight away (and there’s Ockham’s Razor to consider, as you say!), but on the face of it I’d have expected the jump start to overcome that. Having said that, I’m not at all surprised by what you’ve said, especially with the smart charging stuff (and not even attempting to start when it feels the battery is too flat) which modern cars have.

I will have a ponder, and see if I can borrow a hefty battery from a running car as a sanity check. Failing that, I may well take a punt and just order a new AGM battery. I bet that’ll be cheap

cheers

James

[foggyjames]

A little update this morning. Scanned with VIDA. Battery voltage looks fine. ECM is "Not responding". Strikes me that that could be power, network, or an internal fault.

VIDA says that it's in the "cold zone", which I think is Volvo-code for the scuttle area. Can anyone confirm?

Any bright ideas on where to go with this next? My thought is to have a look at the ECM, and check it's nothing obvious (waterlogged, damaged wiring, etc). I think I'm looking at a long tow home, unless I get very lucky!

cheers

James

[Peter2400]

No i don't have start-stop and just regular lead acid battery. Keep in mind that even voltage is ok without a load, it can be still faulty when under load. Sorry im not so familiar with vida diagnostics (i only have the software which i use for getting part numbers and checking removal methods). But as i remember the ecm is under somewhere the "scuttle panel" under the windshield.

[foggyjames]

Thanks Peter. Yes, I found the ECM under the scuttle panel. I'm sure if you sit through the proper dealer technician training, you know exactly what the "cold zone" is! Sadly re-seating the connectors didn't do any good. The ECM is dry as a bone, and the pins are corrosion-free. All fuses are in-tact. With the tools I have to hand, that's about all I can do. My next steps are to investigate recovery and/or professional diagnostic options.

In fairness, I had very good service from a Volvo dealer last time I hit a major problem. I managed to convince them that I wasn't their average punter, and they put their master tech straight on to it. He did some thorough work for a reasonable price, and caught some things I would most likely have missed.

I also tried another battery earlier - one freshly charged (and thought to be good). Sadly it appears that this second battery is well past it, as the supply voltage was dropping fast, although the behaviour (ECM dead, everything else talking) was still the same. On that basis, I am leaning towards thinking that it's not the battery.

Further thoughts tonight:
1) The EML will come on if the car is left on ignition position II for a while; something VIDA reports as a sign that the ECM has power.
2) A friend suggested that it's possible that an immo fault will disconnect the ECM from the network as a security feature. Seemed a bit far-fetched at the time, but a friend who has good knowledge of the electronics side of modern cars suggested exactly that, without prompting. Anyone got any thoughts on that?

cheers

James

[Peter2400]

Yes, i think it's possible. Other "common" no start issues with p3 volvos is problem the steering lock. Try which is shown in this vid: https://m.youtube.com/watch?v=B0HTbDftz30

[foggyjames]

Thankfully no problems with that.

I'm just looking into options, but I think it's going off for professional diagnostics before going any further. Currently trying to work out if that will be near where it is, or whether I'll get it hauled home.

cheers

James

[reggit]

Read a few recent issues on here concerning the in-line fuse on the +ve battery terminal. Have you tried bridging that to see if life returns?

[foggyjames]

I haven't, but I've also run out of time to look into it any further before I have to abandon it where it is for a couple of weeks.

I was chatting to a friend (who happens to run an independent specialist) earlier, and he reckons it's either a dead CEM, a dead ECM, or the wiring in-between. I think it's going to end up going to him.

cheers

James