V90 Phantom Diagnosis??

[driver219]

I write this as a V90 T6 2018 owner, but aware that the below could easily apply to any Volvo estate which uses a CAN bus system. These last two months an intermittent error has been appearing twixt the rev counter & speedo dials: ‘malfunction of rear position lights’. By ‘intermittent’ I mean sometimes everything is ok, the RP lights are functioning; when the error is present the near-side RP LED is out both on the NS post and the tail-gate. Just as the car was approaching its annual service, the error seemed to disappear only to be replaced by a SINGLE error message saying ‘malfunction of the direction indication system’. On completely switching off, and restarting this error has not appeared since. At the annual service I am advised that there are errors present concerning failure of the NS post RP lights, and the replacement cost would be £610!! Somewhere in my tiny brain I asked myself what’s common to these two errors, real or imaginary?? One option would be the power supply. Because I notice that the Engine Start/Stop function is operating less frequently I ask the technician at the annual service to check the Battery System health. Approx 75% capacity is the response. They charge the battery and everything is perfect!! Since then I have acquired a ‘smart battery charger’ and completely re-conditioned the Battery System. Everything is perfect!! Any comments??

[Simmy]

all volvos are voltage critical it can manifest multiple faults on lots of different models. a good battery and alternator is a a must have . ask me how i know.

[driver219]

Thankyou Simmy!! So have you had similar experiences?? Neville

[neilgorin]

Modern computerised cars.

My wife's car eats a battery every other October as soon as we get the first frost.

First sign it's wrong is you approach the car and the wipers slowly move across the screen.

Next sign is you start the engine and it says "Power Steering Failure" followed by "Low Oil Pressure" and "Service Gear Shifter". They all go as you drive off.

The next morning the battery is dead. Dead dead, recharge it and it's dead again the next day.

New battery cures it for exactly 2 years. There's never been a power steering fault, a oil pressure fault or an issue with the shifter, but the battery drops enough that the computer gets a stray signal and thinks that there is.