What Does C0594 Mean?
This code indicates the Antilock Brake System (ABS) or Electronic Stability Control (ESC) module has detected an open circuit in the right rear wheel speed sensor solenoid or hydraulic control solenoid valve circuit. The control module is unable to energize or control the solenoid due to a break in the electrical path between the module and the solenoid. This prevents proper modulation of brake pressure to the right rear wheel during ABS or traction control events.
Common Causes
45%
Damaged or corroded wiring harness between ABS module and right rear solenoid, including chafed wires, broken conductors, or corrosion at connectors
30%
Failed right rear hydraulic control solenoid valve inside the ABS hydraulic control unit
15%
Loose, corroded, or damaged connector at the ABS module or solenoid valve
10%
Failed ABS control module with internal circuit board damage or driver circuit failure
Diagnostic Steps
1
Step 1: Visually inspect the ABS module and all wiring harness connections leading to the right rear wheel area for obvious damage, corrosion, bent pins, or disconnected connectors. Pay special attention to areas where the harness passes through body panels or near the rear suspension.
2
Step 2: Using a digital multimeter, backprobe the solenoid connector at the ABS hydraulic unit and measure resistance across the right rear solenoid terminals (typically 2-6 ohms for most solenoids). Compare to manufacturer specifications. An infinite reading confirms an open circuit in the solenoid coil.
3
Step 3: Disconnect the ABS module connector and measure continuity from the module connector pins (corresponding to right rear solenoid control) through to the solenoid connector. Check both the power supply and ground circuits. An open reading indicates wiring harness failure.
4
Step 4: If wiring and solenoid resistance test normal, perform a voltage drop test while commanding the solenoid active using bi-directional controls in the scan tool. Excessive voltage drop (>0.5V) indicates poor connections or high resistance in the circuit.
5
Step 5: If all circuits test normal but the code persists, suspect internal ABS module failure. Verify module ground connections are clean and tight, then consider module replacement or professional bench testing of the hydraulic unit.
Estimated Repair Cost
$150 - $1,200
Parts + labor, varies by vehicle and location
This code indicates the Antilock Brake System (ABS) or Electronic Stability Control (ESC) module has detected an open circuit in the right rear wheel speed sensor solenoid or hydraulic control solenoid valve circuit. The control module is unable to energize or control the solenoid due to a break in ...
The most common cause of C0594 (Right Rear Solenoid Circuit Open) is: Damaged or corroded wiring harness between ABS module and right rear solenoid, including chafed wires, broken conductors, or corrosion at connectors
Typical repair costs for C0594 range from $150 to $1,200, depending on the vehicle, location, and whether you do it yourself or go to a shop.
The vehicle is generally safe to drive with normal braking function maintained, but ABS and traction control will be disabled or limited at the right rear wheel. Avoid aggressive braking or driving in slippery conditions until repaired, as wheel lockup may occur during hard braking.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to C0594 to identify the root cause.
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Quick Info
Category
Chassis
System
Antilock Brake System (ABS) / Electronic Stability Control
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
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