Damaged or corroded wiring harness at the left rear wheel, particularly where it flexes near the suspension.; Failed ABS solenoid valve inside the hydraulic control unit, specifically the left rear outlet valve.; Corroded or loose electrical connector at the ABS module or at the valve body.; Internal short or open in the ABS control module itself, though this is less common than wiring issues.; Brake fluid contamination or debris causing the valve to stick mechanically, which may set an electrical code indirectly.; Poor ground connection for the ABS module or valve body, leading to voltage irregularities.

DTC codes / C00xx · Brakes, steering and suspension / C0019

C0019Left Rear Outlet Control

Q: What does code C0019 mean?

Left Rear Outlet Control. C0019 is a generic chassis code indicating a fault in the left rear outlet control circuit, which typically refers to a hydraulic solenoid valve in the anti-lock braking system (ABS) or electronic stability control (ESC) module that manages pressure to the left rear wheel. The control module has detected an electrical abnormality—such as an open circuit, short to ground, or short to power—in the wiring or solenoid itself, and it has stored this code while illuminating the ABS warning light.

C0019 is a generic chassis code indicating a fault in the left rear outlet control circuit, which typically refers to a hydraulic solenoid valve in the anti-lock braking system (ABS) or electronic stability control (ESC) module that manages pressure to the left rear wheel. The control module has detected an electrical abnormality—such as an open circuit, short to ground, or short to power—in the wiring or solenoid itself, and it has stored this code while illuminating the ABS warning light.

SystemChassis

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaBrakes, steering and suspension

Symptoms you may notice

ABS warning light illuminated on the dashboard, often accompanied by the traction control or stability control light.
The ABS system may be disabled, leading to conventional braking without anti-lock assistance during hard stops.
A soft or spongy brake pedal feel if the outlet valve is stuck open, though this is less common.
In some vehicles, the stability control system may intervene unnecessarily or be completely inoperative.
Often no symptoms besides the warning light, especially if the fault is intermittent or only affects a single valve circuit.
Possible diagnostic trouble codes in other modules, such as wheel speed sensor codes, if the fault is related to a shared circuit.

Common causes, most likely first

Damaged or corroded wiring harness at the left rear wheel, particularly where it flexes near the suspension.
Failed ABS solenoid valve inside the hydraulic control unit, specifically the left rear outlet valve.
Corroded or loose electrical connector at the ABS module or at the valve body.
Internal short or open in the ABS control module itself, though this is less common than wiring issues.
Brake fluid contamination or debris causing the valve to stick mechanically, which may set an electrical code indirectly.
Poor ground connection for the ABS module or valve body, leading to voltage irregularities.

How to diagnose and fix it

Inspect the wiring harness and connector at the left rear wheel for chafing, corrosion, or loose pins; repair as needed.
Check the ABS module connector for tightness and corrosion; clean and reseat if necessary.
Measure resistance of the left rear outlet solenoid valve at the ABS module connector and compare to manufacturer specifications.
Perform a voltage drop test on the power and ground circuits to the ABS module to rule out high resistance.
Use a scan tool to command the left rear outlet valve and listen for an audible click; no click indicates a faulty valve or circuit.
If the valve is electrically sound, test the ABS module with a known-good unit or perform a module reprogramming if applicable.
Replace the ABS hydraulic control unit or module only after all wiring and connector issues have been ruled out.

Hidden causes of left rear outlet valve codes

A sticking valve due to contaminated brake fluid can set an electrical code because the increased current draw is detected by the module, so flushing the fluid is a wise first step.
The left rear outlet valve shares a circuit with other valves in some ABS modules, so a fault in a common power or ground can trigger multiple codes; always check for related codes like C0018 or C0020.
Intermittent codes often appear after driving over rough roads or in wet conditions, pointing to a wiring harness issue rather than a failed valve.
Some vehicles require a relearn or calibration procedure after replacing the ABS module, which a generic scan tool may not support; a factory-level tool is often necessary.
A weak battery or charging system can cause the ABS module to log false valve codes due to low voltage during cranking, so always verify battery health before condemning the valve.

Can I keep driving with C0019?

You can generally drive the vehicle with this code, but the ABS and stability control systems may be disabled, so exercise extra caution in slippery conditions or during emergency braking. Avoid towing heavy loads or driving at high speeds until the fault is repaired, as the reduced safety systems increase stopping distances.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.