What Does C1177 Mean?
The park brake actuator assembly switch released-position circuit has failed. This switch confirms that the electronic parking brake actuator has fully retracted (released). Without this confirmation, the ABS module cannot verify that the parking brake is completely disengaged, which may affect hill-start assist, ABS calibration, and stability control behavior. The parking brake warning light may remain on even after the brake is released.
Common Causes
35%
Faulty park brake actuator assembly switch (internal failure in released position circuit)
25%
Wiring damage between the actuator switch and the ABS/parking brake module
20%
Park brake actuator not fully releasing, preventing the switch from closing
20%
Corroded or damaged connector at the actuator assembly
Diagnostic Steps
1
Command the parking brake to release via the switch or scan tool. Listen for the actuator motor running. If it does not run, suspect the actuator motor or its power supply rather than the switch circuit.
2
With the parking brake commanded released, disconnect the actuator assembly connector and measure continuity across the released-position switch pins. It should read near 0 ohms when fully released. If OL, either the switch is faulty or the actuator has not physically retracted.
3
Verify the rear brake calipers are not seized by checking that the rear wheels spin freely when the parking brake is released. Seized calipers will prevent the actuator from reaching the released position.
4
Check the wiring from the actuator switch to the ABS module for opens, shorts, or chafing. Pay attention to harness routing under the vehicle where road debris and moisture cause damage.
5
If the actuator motor runs but the switch never closes, the actuator mechanism may be binding. Inspect the park brake cables for corrosion, kinks, or insufficient lubrication.
Estimated Repair Cost
$100 - $500
Parts + labor, varies by vehicle and location
The park brake actuator assembly switch released-position circuit has failed. This switch confirms that the electronic parking brake actuator has fully retracted (released). Without this confirmation, the ABS module cannot verify that the parking brake is completely disengaged, which may affect hill...
The most common cause of C1177 (Park Brake Actuator Assembly Switch Released Circuit Failure) is: Faulty park brake actuator assembly switch (internal failure in released position circuit)
Typical repair costs for C1177 range from $100 to $500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
If the parking brake is physically releasing but the switch circuit is simply not reporting it, driving is generally safe. However, if the parking brake is partially engaged (dragging), continued driving will overheat the rear brakes and could cause brake failure. Verify the rear wheels spin freely before driving.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to C1177 to identify the root cause.
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Quick Info
Category
Chassis
System
ABS / Parking Brake System
Difficulty
Type
Manufacturer
Recommended Tools
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