What Does C1156 Mean?
This code indicates the ABS control module has detected an open circuit in the left front wheel speed sensor circuit. There is a complete break in the electrical connection between the LF sensor and the ABS module, resulting in no speed signal from that wheel. This is typically a wiring or connector issue, though a sensor with a burned-open coil can also cause this condition.
Safety Warning
ABS and traction control are disabled. No LF wheel speed data is available to the module. Repair promptly.
Common Causes
30%
Broken wire in the LF sensor harness from steering/suspension cycling or road debris impact
25%
Disconnected or backed-out connector at the sensor or at a splice/junction
25%
Failed wheel speed sensor with internally open coil winding
20%
Severely corroded connector terminals creating high resistance that reads as an open to the module
Diagnostic Steps
1
Step 1: Verify the LF sensor connector is fully engaged and locked. Inspect for backed-out terminals or bent pins.
2
Step 2: Measure sensor coil resistance (800-1400 ohms typical). An OL reading means the coil is open and the sensor needs replacement.
3
Step 3: If sensor resistance is normal, test wiring continuity from the sensor connector to the ABS module connector on both wires.
4
Step 4: Locate any break by testing continuity at intermediate connectors or splice points along the harness route. Common break points are at flex areas near the steering knuckle.
5
Step 5: Repair the open or replace the sensor, clear codes, and road test above 15 mph to verify LF speed signal.
Estimated Repair Cost
$80 - $350
Parts + labor, varies by vehicle and location
This code indicates the ABS control module has detected an open circuit in the left front wheel speed sensor circuit. There is a complete break in the electrical connection between the LF sensor and the ABS module, resulting in no speed signal from that wheel. This is typically a wiring or connector...
The most common cause of C1156 (Speed Wheel Sensor LF Circuit Open) is: Broken wire in the LF sensor harness from steering/suspension cycling or road debris impact
Typical repair costs for C1156 range from $80 to $350, depending on the vehicle, location, and whether you do it yourself or go to a shop.
ABS and traction control are disabled. No LF wheel speed data is available to the module. Repair promptly.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to C1156 to identify the root cause.
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Quick Info
Category
Chassis
System
Anti-lock Brake System (ABS) / Traction Control System
Difficulty
Type
Manufacturer
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