V70 Shutdown while driving

Post by **Fiodor** » 04 Jun 2018, 15:17

Hey, I've got a 1997 V70 AWD italian T5 (B5204T3) that sometimes shuts off while driving.
When it does it's only for a second, the dashboard turns off, the engine stops and then all the lights on the dashboard turn on and the engine starts running again.
I've also noticed that the ABS light turns on if I push hard on the pedal in first and second gear although it still turns off when I slow down.
I've been running 100% E85 with a flexfuel kit for a year now so I'm not sure if it could be related.
Do you have any ideas about what might be the source to my problems ?
Thanks !

Post by **FLXC90** » 04 Jun 2018, 18:21

Check The electrical Portion of the ignition switch. Also check the condition of your battery cables and B+ cable to the fusebox. It doesn't sound fuel related because the dash losing power.
When you push hard on the pedal in first or second gear, is there wheel slip? If so, that might trip the ABS system, otherwise, these cars control modules ALL fail eventually. There are many related texts that list a European repair station for the modules. viewtopic.php?f=1&t=84041

Post by **Fiodor** » 05 Jun 2018, 03:45

Hey, thanks for the reply!
I cleaned thoroughly the ends of the battery cable and the ground connection in front of the battery.
The cables don't look damaged.
The ABS repair is just about opening the ABS module and reflowing some pins? It's not too difficult if you know how to solder?
Is there a way to test the ignition switch?
I don't think there's tyre slip when the issue happens, it happened once as I was turning on a roundabout at 25 km/h so I'm sure there wasn't any tyre slip this time.

Post by **abscate** » 05 Jun 2018, 04:36

Both Lee and I did tear downs of the ignition switch which showed the failure modes, but it I still hard to be definitive. It is about a $50 part here, they are known to fail at 125000 miles or so standard driving

Post by **Fiodor** » 05 Jun 2018, 05:06

And what are the symptoms?

Post by **abscate** » 05 Jun 2018, 06:27

For ignition switch - dashboard electrical failures are common, intermittent failures of stuff.

Mine started to work when I thumped the steering column.

There are about 10 electrical connections in the ignition switch so what can fail can be pretty widely spread out.

Was there any electrical work done with that flex fuel kit? Electrical stuff on Volvo is pretty good, it might pay to look over the aftermarket workmanship.

Post by **June** » 05 Jun 2018, 06:29

It is worth noting heavy chains of keys aggravate the problem with ignition switches. The excess weight swings as you accelerate and break moving the switch. Try to drive with just the key and see if it helps your problem. You can also jiggle the key to see if the engine cuts out. I had the switch fail in my 960 from my heavy large keychain according to the dealer back then. Since then I strictly only use the Volvo key without the chain In the ignition and keep my keys and keychain separate. It is worth noting the ignition switch in my Volvo now has never given trouble and it has been over 14 years now. June

Post by **Fiodor** » 05 Jun 2018, 06:35

I just had to connect the kit to the - terminal.
I'm going to try and drive with nothing attached to my key.
Thanks again for all the advices !

Post by **abscate** » 05 Jun 2018, 06:40

Ill guess on your 960 the electrical and mechanical parts of the switches were integral, while on the P80 they are not. You can remove the 'electrical part of the ignition switch' with a couple of Torx bolts - no drilling or removing of lock cylinders required. 10 minute job.

That design separates the weight of keychains from the electrical part

The P2 switch seems much more robust - few failures reported here or in the P2 Forum

Post by **abscate** » 05 Jun 2018, 06:41

You can also jiggle the key to see if the engine cuts out

..and try this in a safe place, like circling the Arc d'Trump....did I spell that right?