FAQ
TL;DR: Case study: 1 persistent right‑rear ABS sensor DTC after replacement; “Pin and read all system errors.” Fixes range from wiring and cracked tone rings to steering retractor faults. [Elektroda, Strumien swiadomosci swia, post #16825732]
Why it matters: This FAQ helps Volvo S60/V70 D5 owners quickly triage ABS/Anti‑Skid faults and choose the next best diagnostic step.
Quick Facts
- Symptom: ABS light on + “Anti‑Skid Service Required,” ABS disabled; pump swap alone did not help. [Elektroda, said22, post #16825716]
- A right‑rear wheel‑speed sensor DTC can persist after sensor replacement if wiring or the tone ring is faulty. [Elektroda, said22, post #16825747]
- First checks: scan all modules and verify the sensor circuit (“installation”) before more parts. [Elektroda, Strumien swiadomosci swia, post #16825773]
- A cracked ABS tone ring (“crown”) can trigger ABS/Anti‑Skid warnings without a bad sensor. [Elektroda, lechr, post #19810688]
- Steering retractor/angle‑sensor faults may raise Anti‑Skid errors; regeneration/replacement can resolve them. [Elektroda, przemyslawwojcikowsk, post #19771372]
What does “ABS/Anti‑Skid Service Required” mean on a 2003 Volvo S60/V70 D5?
The ABS module has disabled anti‑lock and stability assistance due to a detected fault. In the thread, the warning stayed on despite an ABS pump swap and pointed to the right‑rear sensor. That means braking works, but ABS and anti‑skid are inactive until the root cause is fixed. [Elektroda, said22, post #16825716]
Will replacing a wheel‑speed sensor clear the ABS light automatically?
It can, but not if the underlying issue is elsewhere. In this case, a new right‑rear sensor did not clear the DTC or the warning. The mechanic expected it to clear itself, yet the fault persisted, indicating another problem such as wiring or the tone ring. [Elektroda, said22, post #16825747]
How do I diagnose a persistent right‑rear sensor fault at home?
Follow three steps:
- Scan all systems and note exact DTCs and wheel location.
- Inspect sensor connector, routing, and hub area for damage or debris.
- Check the tone ring for cracks and test wiring continuity to the module.
“Pin and read all system errors.” [Elektroda, Strumien swiadomosci swia, post #16825732]
Could damaged wiring or connectors be the real cause?
Yes. A sensor code can result from open circuits, corrosion, or broken wires between the hub and ABS module. The advice in‑thread was to check the installation (wiring harness) thoroughly before more parts. Movement near the wheel often stresses these wires. [Elektroda, Strumien swiadomosci swia, post #16825773]
What is the ABS tone ring (crown), and how can it fail?
The tone ring is a toothed encoder on the axle or hub that the sensor reads. If the ring cracks or rust swells, the sensor sees erratic signals and triggers ABS/Anti‑Skid warnings. Visual inspection around the CV joint or hub usually reveals splits or missing teeth. [Elektroda, lechr, post #19810688]
Can a bad steering retractor/angle sensor cause an Anti‑Skid error?
Yes. A faulty steering retractor (steering angle sensor assembly) can set Anti‑Skid warnings even when wheel sensors are fine. Regeneration or replacement of the retractor often restores correct stability control inputs. “If I can help in regeneration, call…” reflects this fix path. [Elektroda, przemyslawwojcikowsk, post #19771372]
I replaced the ABS pump/module with the same number. Why no change?
Because the pump was not the root cause. The original poster swapped the pump module and still had the ABS/Anti‑Skid warning and a right‑rear sensor code. Replace only after confirming the module is faulty; otherwise, check wiring, sensor, and tone ring first. [Elektroda, said22, post #16825716]
The scanner shows communication issues. What’s the next step?
Seek a workshop experienced with Volvo diagnostics. Network or multi‑module faults complicate DIY troubleshooting and require VIDA‑capable tools and know‑how. As one reply states, “None, go to a workshop that embraces Volvo because it’s not a simple diagnosis.” [Elektroda, piotrekwoj1, post #21286017]
What is CAN bus in this context?
CAN bus is the in‑vehicle network that lets modules like ABS, ECM, and steering angle sensors exchange data. Faults on CAN can surface as ABS or Anti‑Skid warnings. Think of it as the car’s data backbone for safety and powertrain systems. “Controller Area Network.” [Controller Area Network]
Do ABS faults always clear themselves after a fix?
No. Some clear after a successful repair and short drive. In the thread, the light did not clear after a sensor swap, proving the fix was incomplete. Clear codes only after addressing the actual fault path and confirming live data looks correct. [Elektroda, said22, post #16825747]
What quick checks should I ask my mechanic to perform first?
Ask for: a full‑system scan with freeze‑frame data, visual inspection of the wheel‑speed sensor harness, and verification of the reported wheel location. The expert advice was clear: “Pin and read all system errors,” then proceed methodically. [Elektroda, Strumien swiadomosci swia, post #16825732]
I see multiple different fault suggestions—how do I prioritize?
Start with evidence: the exact DTC and wheel location. Validate sensor power/ground and signal. Inspect the tone ring. Only then consider steering retractor or ABS module. One case logged 1 unchanged DTC after parts swaps, highlighting the need for basic checks first. [Elektroda, said22, post #16825747]
Could a cracked tone ring cause intermittent ABS activation at low speed?
Yes. A split tooth ring can produce dropouts that the module interprets as a locking wheel, often at parking speeds. This presents as pulsation, then the warning stays on. Replacing the damaged ring restores a clean signal. [Elektroda, lechr, post #19810688]
When should I stop DIY and book professional diagnostics?
If codes reappear after sensor replacement, if wiring checks pass, or if scans show network communication errors, stop and book a Volvo‑savvy shop. As one reply notes, this diagnosis is not simple without the right tools. [Elektroda, piotrekwoj1, post #21286017]
