Hi All,

I own a 2010 Volvo C30 1.6 Diesel. It has 120,000 miles. Recently I’ve had an issue where the car will completely cut out while driving. This typically happens around 3rd to 5th gear and usually when I take the car about 2000rpm. I have to turn the the key off and on to start the car back up and it carries on driving as normal. I sometimes have a Low Voltage Remove Battery warning light but not very often, the car had a new battery not long ago. I had a mechanic plug it into a diagnostic machine but there was no error codes showing. He said there isn’t much he can do. Can any advise me what this could possibly be?

Thanks in advance!

 

sounds like you have a failing relay somewhere, possibly in the voltage regulator. Intermittant electrical issues are often the hardest thing to diagnose - how often does this happen? can you reproduce it? It may require driving with an OBD2 monitor trying to capture some live data.

 

Thank for the reply!

Id say it’s happening 50% of the time I drive the car now. Seems to happen more often at cold weather but that may just be coincidence that it’s failing at this time of year. One thing I’ve noticed is it doesn’t happen at all when idling. Only when power is applied.

 

I had a related experience - my battery light would come on, but only on cold days when first starting out. I'd stop, restart and voila, no more battery light. Finally happened to be picking up the car from a servicing when the battery light came on so the service manager came out with a multi-meter to test and had me restart. Wound up replacing the alternator/voltage regulator which cured the problem. Turns out that one of the relays in the VR used to keep the battery from overcharging was sticking so when it tried to lower the voltage it stayed in the open position. My thinking is you have something similar - the question is which relay - ie fuel pump? fuel injectors? ECU? etc. Another possible cause is a connector - maybe reseating the ECU or CEM connectors may be enough to scuff up a marginal connection that opens when the contacts are cold.