What Does C1259 Mean?
The ABS control module has detected a wheel speed comparison failure at the right front wheel. The module's internal plausibility checks have determined that the right front wheel speed sensor is reporting a speed significantly different from the other three wheels during conditions when all should be similar, indicating a sensor accuracy problem.
Safety Warning
Inaccurate right front wheel speed data will cause ABS and traction control to malfunction. The system may activate unexpectedly or fail when needed. Repair promptly.
Common Causes
30%
Mismatched or improperly sized tire on the right front causing different rotational speed
25%
Contaminated, cracked, or improperly seated right front wheel speed sensor
25%
Damaged or corroded ABS tone ring on the right front hub assembly
20%
Worn right front wheel bearing allowing sensor air gap variation
Diagnostic Steps
1
Step 1: Confirm all four tires are the same size, brand, and have comparable tread depth. Even a spare tire with different diameter can trigger this code.
2
Step 2: Compare all four wheel speed readings via live data at a steady 30 mph on a straight road. Identify if the right front is consistently reading high or low.
3
Step 3: Inspect the right front sensor for proper mounting, correct air gap, and freedom from metallic debris. Clean the sensor face and tone ring area.
4
Step 4: Rotate the right front wheel by hand while monitoring the speed signal in live data. Look for dropouts, spikes, or erratic signal patterns indicating tone ring damage.
5
Step 5: Check right front wheel bearing for play. If all mechanical checks pass, swap the left and right front sensors to see if the fault follows the sensor. Clear codes and test drive.
Estimated Repair Cost
$80 - $450
Parts + labor, varies by vehicle and location
The ABS control module has detected a wheel speed comparison failure at the right front wheel. The module's internal plausibility checks have determined that the right front wheel speed sensor is reporting a speed significantly different from the other three wheels during conditions when all should ...
The most common cause of C1259 (Speed Wheel RF Comparison Failure) is: Mismatched or improperly sized tire on the right front causing different rotational speed
Typical repair costs for C1259 range from $80 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Inaccurate right front wheel speed data will cause ABS and traction control to malfunction. The system may activate unexpectedly or fail when needed. Repair promptly.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to C1259 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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