Wonky Speedo followed by DSTC Warning and many others!

[Hotravco]

My 2009 XC60 D5 AWD has been throwing up many errors recently and the first sign it’s going to throw a wobbly is the Speedo going wild followed by DSTC fault service required.

I went into my local independent garage who I know and trust to have Codes read and heat shield fixed. They said there were so many error codes that they cleared them and to take the car away and come back when they would read again to try to pinpoint the cause.

So today all the same codes pop up after the Speedo dance plus now the gearbox doesn’t change up/down from whatever gear it’s in. But you can restore normality but switching right off and then back on again until it all happens again. It’s booked back in at the garage on Thursday but

Any advice please about where to start?

[Tannaton]

I'd be suspecting a charging/power issue - I would get the battery tested, alternator output tested and check the alternator pulley (overrun clutch) is working as it should.

When the system voltage gets low, all sorts of random errors get logged from the ABS, steering, gearbox etc.

I think it will be something really simple and relatively cheap - it's just diagnosing it!

[Clan]

Originally Posted by Hotravco

My 2009 XC60 D5 AWD has been throwing up many errors recently and the first sign it’s going to throw a wobbly is the Speedo going wild followed by DSTC fault service required.

I went into my local independent garage who I know and trust to have Codes read and heat shield fixed. They said there were so many error codes that they cleared them and to take the car away and come back when they would read again to try to pinpoint the cause.

So today all the same codes pop up after the Speedo dance plus now the gearbox doesn’t change up/down from whatever gear it’s in. But you can restore normality but switching right off and then back on again until it all happens again. It’s booked back in at the garage on Thursday but

Any advice please about where to start?

your fault is probably linked to a faulty wheel sensor or toothed ring. The speedo flicker is the clue. Are there any codes relating to that?

[Tannaton]

Originally Posted by Clan

your fault is probably linked to a faulty wheel sensor or toothed ring. The speedo flicker is the clue. Are there any codes relating to that?

I'd be inclined to agree, but what swayed me was the gearbox symptoms and that his odometer seems to have cleared as well.....

I *think* (but would appreciate your view) that on some models the speed sensor for the instruments is on the LH wheel and on some models comes from the gearbox output sensor?

[Clan]

Originally Posted by Tannaton

I'd be inclined to agree, but what swayed me was the gearbox symptoms and that his odometer seems to have cleared as well.....

I *think* (but would appreciate your view) that on some models the speed sensor for the instruments is on the LH wheel and on some models comes from the gearbox output sensor?

The gearbox has a speed sensor signal going to it as well. and if the odometer isn't getting a signal perhaps it goes blank so as not to give a misleading signal .. over the years the speed signal comes from the BCM , which wheel though I'm not sure, maybe it is an average of all 4....

[Hotravco]

Originally Posted by Clan

your fault is probably linked to a faulty wheel sensor or toothed ring. The speedo flicker is the clue. Are there any codes relating to that?

Yes many - see attached!