SureTrack Real Fix: Shafted Sensor

Real Fixes from ShopKey’s SureTrack® expert information resource are documented issues from actual shop repair orders and community discussions. Read on to see how SureTrack can help you correct issues that are not easily diagnosed using OEM information alone. SureTrack is currently available free with the purchase of a current Snap-on® diagnostic software version or in our ShopKey Pro product.

The anti-lock brake (ABS) system in vehicles relies on sensors to operate. These sensors capture the rotation of the wheels, typically through interfacing with a notched sensor ring. If this ring gets damaged, the system will not operate properly. Follow this Real Fix to see diagnosis of ABS codes on this Mercury Mariner lead to a damaged sensor ring and the repair.

2006 Mercury Mariner Base 3.0L

C1233, U0415, U2023, Replaced Axle Shaft

The customer states the anti-lock brake system (ABS) light is on.

Connected a scan tool and found codes: C1233 – Wheel Speed Sensor LF Input Signal Missing; U0415 – Invalid Data Received From Anti-Lock Brake System (ABS) Control Module and U2032 – Fault Received From External Node. Performed a road test, used the scan tool to monitor live data and found the left front ABS wheel speed sensor signal parameter was erratic. Backprobed the left front ABS wheel speed sensor and monitored the sensor signal on a lab scope while spinning the left front wheel by hand. The left front ABS wheel speed sensor produced an erratic signal on the lab scope. Visually inspected the left front wheel speed sensor and wiring harness and found the left front abs sensor ring was damaged. The left front abs sensor ring is integrated into the left front axle shaft and is replaced as a unit.

Replaced the left front axle shaft, cleared codes, performed a road test and verified the vehicle operated properly.

SureTrack® adds to the power of ShopKey Pro with an exclusive combination of expert knowledge and detailed parts replacement records, all wrapped in an interactive community. Designed to help automotive shops increase accuracy and efficiency from diagnosis to completed repair, the industry’s most comprehensive repair information resource is just a few clicks away.

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About the Author

Nick Taylor

Nick Taylor is the SureTrack Community Administrator and a Senior Applications Specialist at Mitchell 1 with over 25 years of experience with electronic repair data systems. Nick previously worked in the automotive dismantling and engine rebuilding industries.