Damaged, corroded, or open wiring or connector at the right rear outlet solenoid valve on the ABS modulator; Failed right rear outlet solenoid coil inside the hydraulic control unit; Faulty ABS control module driver circuit for that specific valve; High resistance or short to ground in the outlet control circuit due to chafed harness or water intrusion; Poor ground connection for the ABS modulator assembly; Intermittent connection caused by vibration or thermal cycling at the valve connector

DTC codes / C00xx · Brakes, steering and suspension / C001D

C001DRight Rear Outlet Control

Q: What does code C001D mean?

Right Rear Outlet Control. C001D is a generic chassis code indicating that the electronic brake control module has detected a fault in the right rear outlet control circuit, which manages hydraulic pressure release to that wheel during antilock braking and stability control events. The module monitors the outlet solenoid valve circuit for abnormal voltage or current and sets this code when the signal falls outside the expected range.

C001D is a generic chassis code indicating that the electronic brake control module has detected a fault in the right rear outlet control circuit, which manages hydraulic pressure release to that wheel during antilock braking and stability control events. The module monitors the outlet solenoid valve circuit for abnormal voltage or current and sets this code when the signal falls outside the expected range.

SystemChassis

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyProfessional

AreaBrakes, steering and suspension

Symptoms you may notice

Antilock brake system (ABS) warning light illuminated on the dashboard
Traction control or stability control warning light also on, since these systems share the same hydraulic modulator
ABS may be disabled, with normal braking still available but no antilock function during hard stops
During low-speed braking or a panic stop, the right rear wheel may lock or the pedal may feel unusually firm or unresponsive
Often no symptoms besides the warning light, especially if the fault is intermittent or only affects a single valve circuit

Common causes, most likely first

Damaged, corroded, or open wiring or connector at the right rear outlet solenoid valve on the ABS modulator
Failed right rear outlet solenoid coil inside the hydraulic control unit
Faulty ABS control module driver circuit for that specific valve
High resistance or short to ground in the outlet control circuit due to chafed harness or water intrusion
Poor ground connection for the ABS modulator assembly
Intermittent connection caused by vibration or thermal cycling at the valve connector

How to diagnose and fix it

Scan all modules and record freeze-frame data to confirm C001D is current and not a history code from a past event
Visually inspect the right rear outlet solenoid connector and harness for corrosion, chafing, or loose pins, and clean or repair as needed
Measure resistance of the right rear outlet solenoid coil at the modulator connector and compare to the manufacturer's specification
Check for short to ground or short to voltage on the outlet control circuit between the ABS module and the valve
Verify the ABS module ground circuit is clean and tight, and perform a voltage drop test under load
If wiring and coil test good, substitute a known-good ABS module or perform bidirectional valve activation with a scan tool to confirm the driver circuit
Clear codes and perform a road test with ABS activation to verify the repair, then recheck for returning codes

What the outlet valve code really tells you

A C001D can be set by a perfectly functional valve if the ABS module sees a momentary voltage spike from a weak battery or poor ground, so always check charging system health before condemning the modulator.
The outlet solenoid is only energized during ABS release phases, so a valve that tests fine statically may still fail under the heat and vibration of actual antilock operation.
Many technicians replace the entire ABS hydraulic unit when the fault is simply a corroded pin in the connector, which is a fraction of the cost and often the real root cause.
This code does not always mean the ABS is completely disabled; some systems retain partial function and only inhibit the affected wheel's antilock release, so a road test may not reveal a obvious symptom.
After repairing the circuit, some vehicles require a steering angle sensor calibration or a ABS bleed procedure with a scan tool before the warning light will clear and stay off.

Can I keep driving with C001D?

You can usually drive the vehicle with C001D set because normal hydraulic braking remains, but the antilock function on the right rear wheel may be compromised. Avoid hard braking or slippery conditions until the fault is repaired, and treat the ABS warning light as a sign to schedule diagnosis promptly.

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.