Audi A7 ABS Fault Diagnosed and Repaired in Walsall
We had an Audi A7 come into us here at Platinum Vehicle Services in Walsall recently with the ABS warning light showing on the dashboard. The owner had noticed it a few days earlier and was not sure whether it was safe to keep driving or whether the car would fail its next MOT. Both were fair concerns, and we were glad they brought it in when they did rather than leaving it any longer.
The ABS Warning Light Was On and the System Had Logged a Fault Code Pointing to the Wheel Speed Sensor
The first thing we did was plug the car into our diagnostic equipment. This is a tool that reads fault codes stored in the car's computer, which tells us exactly which part of the system has flagged a problem rather than us working through the whole car blindly. The code that came back pointed to the ABS wheel speed sensor on the nearside rear, which is the rear left corner of the car. A wheel speed sensor is a small component that sits close to the wheel hub and measures how fast that wheel is rotating. It sends that information to the ABS control unit dozens of times per second while you are driving. Once we had the fault code confirmed, we inspected the sensor physically and found it had failed. The signal it was sending back was either absent or inconsistent, which was enough for the car's system to disable ABS entirely and log the warning.
A Failed ABS Sensor Means the System Cannot Do Its Job When You Need It Most
ABS, which stands for anti-lock braking system, stops your wheels from locking up when you brake hard or brake on a slippery surface. When a wheel locks, you lose the ability to steer the car even if you are still pressing the brake pedal. ABS prevents that by releasing and reapplying brake pressure very rapidly, sometimes dozens of times per second, keeping the wheels turning and letting you steer around whatever is in front of you. With the sensor failed on this A7, the ABS control unit had shut the system down completely as a precaution. The brakes still worked in normal conditions, but in an emergency stop or on a wet road the wheels could lock and the driver would have no steering control. That is a serious safety risk. On top of that, a car with a confirmed ABS fault will fail an MOT, so leaving it would have meant a failed test and the cost of repairing it under time pressure anyway.
We Replaced the Faulty Wheel Speed Sensor and Cleared the Fault Before Road Testing the Car
We fitted a new wheel speed sensor to the nearside rear corner of the A7. Once the sensor was in place and the wheel was back on, we cleared the fault code from the system using the diagnostic equipment and took the car out on a road test. During the test we monitored the live data from all four wheel speed sensors to make sure each one was reading correctly and consistently at the same speeds. All four sensors were reporting accurately, the ABS warning light had cleared and stayed off, and the system was operating as it should. The car went back to the owner fully repaired and ready for an MOT with no ABS related issues outstanding.
If Your Dashboard Is Showing a Warning Light, Do Not Wait to Get It Checked in Walsall
ABS work is something we carry out regularly here at Platinum Vehicle Services, alongside diagnostics, MOT testing, brakes, suspension and general mechanical repairs. If your ABS warning light is on, or any other warning light has come up on your dashboard, it is worth getting it read sooner rather than later. In most cases a diagnostic check will tell us exactly what the fault is within minutes, and the earlier a fault is caught the less it tends to cost to put right. A warning light that is ignored can sometimes lead to a bigger repair bill further down the road, or a vehicle that is not safe to drive. If you are based in or around Walsall and you are seeing a warning light, or you are due a service or MOT, we would be happy to take a look. You can leave us a message any time, 24 hours a day, 7 days a week on 07970901354 and someone from the team will get back to you as soon as possible. You can also find out more and book in at platinumvehicleservices.co.uk.
