🚨 Diagnostic Profile
- Vehicle/Equipment Make: GENERIC
- Technical Description: Rear Drive Shaft Speed Sensor Circuit Low
This code is set by the Electronic Brake Control Module (EBCM) or the ABS/Stability Control Module when it detects that the signal voltage coming from the rear drive shaft (output) speed sensor is lower than the expected calibrated range. This sensor feeds rotational speed data to the chassis control module so it can calculate vehicle speed, wheel slip, and drive shaft rotation for use in the ABS, traction control, and stability control systems. A ‘circuit low’ condition typically indicates a short to ground, a damaged sensor, a corroded connector, or an open/shorted wiring harness between the sensor and the control module. When this fault is active, the module will often disable ABS, traction control, and stability control functions and illuminate the corresponding dashboard warning lights until the fault is cleared and the system passes a self-test.
🚨 Repair Difficulty Tier
- Difficulty Rating: Intermediate
This repair requires the use of a digital multimeter to check for proper resistance and voltage signal from the speed sensor, along with a capable scan tool to read live ABS module data and confirm the fault clears after repair. While the sensor itself is often accessible without major disassembly, working around drive shaft components and connectors near the underbody requires some mechanical experience and proper vehicle lift safety.
🛠️ Resolution Steps
- Step 1: Preliminary Inspection
Visually inspect the rear drive shaft speed sensor, its wiring harness, and connector for signs of physical damage, corrosion, chafing, or exposure to road debris and moisture. Check that the sensor is properly seated and that the connector pins are not bent, corroded, or pushed back out of the housing. - Step 2: Diagnostic Verification
Using a digital multimeter, measure the resistance and output voltage of the speed sensor according to manufacturer specifications, and check for continuity and absence of a short to ground in the wiring harness between the sensor and the control module. Then connect a scan tool to the ABS/chassis module to view live sensor data and confirm if the circuit reads abnormally low or erratic, and verify whether other wheel/drive shaft speed codes are present simultaneously, which may point to a shared ground or module-level issue. - Step 3: Resolution & Reset Process
Repair or replace any damaged wiring/connectors found during testing, or replace the drive shaft speed sensor itself if it fails resistance/voltage specifications. After repairs, clear the stored trouble code with the scan tool, road test the vehicle to allow the module to complete its self-test, and confirm the ABS/traction control/stability control warning lights turn off and the code does not reset.
📦 Parts, Labor, and Budget Estimates
- Required Components/Software: Rear drive shaft speed sensor, wiring harness repair kit/connector (if needed), digital multimeter, ABS-capable scan tool
- Average Component Price: $35 – $90 USD
- Estimated Labor Hours: 0.5 – 1.5 hours
- Total Estimated Budget: $90 – $250 USD