2004 XC70 Tracs/Cruise/Speedo Issues

kimthepilot · Post by **kimthepilot** » 01 Jan 2016, 15:24

Hi All,
My '04 XC70 is showing the following symptoms. The car originally exhibited these issues in a RH turn, but now it seems to happen going straight and slightly left as well. There are no issues in a tight LH turn.
-TRACS light flashing under any acceleration (even on dry pavement, with the lightest of pressure on the gas)
-A scrubbing/clicking/rubbing noise from under the hood while the TRACS light is on (is this the system trying to reduce torque?)
-While cruising the speedometer needle hunts +/- 5ish km/hr
-I suppose because of the speedo hunting, the cruise control hunts as well.

I've done some searching, and have come up with the following diagnoses:
-ABS sensor, or cable going bad
-ABS ring going bad
-Steering position sensor going bad
-Loose axel nuts (I have checked, and they are all tight and torqued to spec)

Is there any troubleshooting I can do?
Would there be any codes readable with VIDA/Dice?
Is it harmful to the car to continue driving it like this?

Thanks for the help!

Kim

Post by **abscate** » 02 Jan 2016, 04:45

Kim ...my guess is one of the ABS sensor wires is intermittent and is shorting or opening on the turn. It could be either one, but an inspection might show damage to the wires. The solid part of the sensor rarely goes bad, IMHE

All of your other symptoms will cascade from that. Once the car isn't sure of speed, a lot of things get unhappy.

Pending or stored codes will show up in VIDA or a higher end scanner.

You might be able to confirm by measuring ABS resistance from the connectors under the hood with the wheel turned hard right. Mattymoo has the resistances documented at MIDWEST abs website

kimthepilot · Post by **kimthepilot** » 27 Jan 2016, 11:38

Hi All,
I'm still working on this issue. I'm pretty sure it's the LH Front sensor.
I inspected the sensors and cables yesterday. The cabling all looked to be in good shape. No cracks, kinks or anything. The end of the Left Front sensor seems to be ground down. The ABS ring looked ok. Not much corrosion. I've attached a pic of the sensor.

Finally found someone with a DICE box in town. The relevant codes in the system were:
BCM-0011 Wheel sensor, Left Front Faulty Signal
BCM-0012 Wheel sensor, left front mechanical error
CEM-1A5F Communication with BCM control module signal missing (We looked into this one. It happened once, and never again since the fault initially happened)

Cleared all the codes, drove around, got the same "ABS/Traction control service required" / Yellow warning / ABS light on. Read the codes, and the only one to reappear was BCM-0011.

I'm planning on changing the sensor and cable, as well as the ABS ring (since it is cheap, and easy).

Is there a possibility this is all wheel bearing related? What would cause the sensor to wear down like that?

Thanks for the help!

Post by **oragex** » 27 Jan 2016, 13:29

Checked this?
https://www.matthewsvolvosite.com/forums ... 57#p368657

kimthepilot · Post by **kimthepilot** » 30 Jan 2016, 15:50

I did take a look at that. It doesn't seem to apply to my issue. I definitely don't have a heat soak problem, as all the symptoms I'm seeing happen when it's -30C outside, as well as when it's 0, and I've been driving for a while.

Any ideas what caused the end of the ABS sensor to be worn away?

kimthepilot · Post by **kimthepilot** » 14 Feb 2016, 09:30

Turns out it was the ABS ring. It was corroded, had split, and since it was larger in diameter, it ground away the ABS sensor. I replaced both items, and the problem is solved.