C1246 — ABS Outlet Valve Coil RR Circuit Failure

C1246 — ABS Outlet Valve Coil RR Circuit Failure. A fault in the ignition system. Short, gentle driving to a shop is usually possible. Typical causes: moisture or oil in the spark plug wells, faulty ignition control circuit in the ECM, failed ignition coil or coil pack.

chassis (brakes/steering/suspension)

Is it safe to drive?

Drive with caution Drive with caution and avoid load. Ignition faults cause misfires that quickly overheat and destroy the catalytic converter; if the Check Engine Light flashes, stop and fix it first.

How to diagnose with an OBD scanner

Read the code and freeze frame Connect an OBD2 scanner, confirm C1246 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many C0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the ignition system for damage, corrosion, chafing or poor contact.
Subsystem check Swap the coil to another cylinder and see if the fault code follows it.
Subsystem check Inspect spark plugs for wear, oil or carbon tracks and check plug gaps.
Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm C1246 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for C1246 (parts and labor, USD, independent shop rates): Replace an ignition coil: $150–$380; Repair coil wiring or connector: $80–$250; Replace spark plugs: $90–$250. Overall, fixing C1246 usually costs between $80 and $380. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

Is it safe to drive with C1246?

Drive with caution and avoid load. Ignition faults cause misfires that quickly overheat and destroy the catalytic converter; if the Check Engine Light flashes, stop and fix it first.

Will C1246 clear itself?

Sometimes C1246 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

What is the most common cause of C1246?

The most common causes are: moisture or oil in the spark plug wells, faulty ignition control circuit in the ECM, failed ignition coil or coil pack.

What are the symptoms of C1246?

Drivers most often notice: hard starting, especially in damp weather, increased fuel consumption, Check Engine Light on, misfires under load or at idle.

How much does it cost to fix C1246?

Replace an ignition coil — $150–$380; Repair coil wiring or connector — $80–$250; Replace spark plugs — $90–$250. Exact cost depends on the root cause, your vehicle and local labor rates — a proper diagnosis is the cheapest first step.

When your vehicle's anti-lock braking system develops an electrical problem with the right-rear wheel's outlet valve circuit, the powertrain or ABS control module stores trouble code C1246. This code belongs to the chassis category, specifically the braking subsystem, and signals that the module has detected an electrical fault in the ABS hydraulic unit's rear-right outlet valve coil circuit. During normal ABS operation, the control unit energizes and de-energizes individual valves hundreds of times per second to prevent wheel lockup. When the circuitry feeding that specific valve fails its self-test, the module logs C1246 and illuminates the ABS warning lamp on the instrument cluster.

Modern ABS units perform continuous self-diagnostics whenever the ignition is on. The module sends tiny electrical pulses through each valve coil and measures the response. If the resistance drifts outside the factory-specified range, or if the circuit goes open or short, the module confirms the fault across multiple drive cycles before committing C1246 to memory. Freeze frame data stored alongside the code captures exact vehicle conditions at the moment of detection—speed, brake pressure input, and system voltage—which helps pinpoint whether the failure occurred during hard braking or while sitting at a stoplight.

Symptoms of C1246

ABS warning light stays illuminated after engine startup
Anti-lock braking function disabled during emergency stops or low-traction maneuvers
Standard brake operation preserved—the vehicle still stops normally without ABS assistance
Possible traction control system warning if the vehicle integrates ABS with stability control
Intermittent ABS activation where the system activates unexpectedly under normal braking
Unusual noises from the ABS hydraulic unit during activation
Reduced brake pedal feel under heavy braking if the valve is stuck in a partial position

Common Causes of C1246

The most frequent culprits for C1246 involve the internal wiring and electrical connections within the ABS hydraulic assembly, which sits in an environment constantly exposed to road salt, heat cycles, and brake fluid moisture contamination.

Corrosion or broken wire inside the ABS module's internal harness to the rear-right outlet valve coil
Failed solenoid valve coil inside the ABS hydraulic unit (most common actual failure point)
Poor electrical connection at the ABS module's external connector due to moisture intrusion or bent pins
Short or open circuit in the vehicle wiring harness between the ABS module and wheel speed sensor wiring (shared connectors)
Faulty ABS control module with damaged output transistors controlling the valve circuit
Aftermarket brake work where connector pins were damaged or harness routing changed
Water contamination inside the ABS module case from a leaking seal or pressure-wash damage

How to Diagnose C1246

Accurate diagnosis requires a systematic approach that rules out simpler electrical problems before concluding the hydraulic unit itself has failed.

Connect an OBD2 scanner or manufacturer-specific diagnostic tool, confirm C1246 is present, and record all available freeze frame data. Note any additional codes stored in the ABS module—sister codes like C1202 through C1205 often point to shared power supplies or ground paths.
Perform a thorough visual inspection of the ABS module's electrical connector. Disconnect it, examine each pin for corrosion, bent contacts, or moisture residue. Check the vehicle harness for chafed insulation, especially near moving suspension components where wires can rub through over time.
Test electrical resistance at the ABS module connector pins corresponding to the rear-right outlet valve circuit against factory specifications. Most units show coil resistances between 5 and 15 ohms; anything drastically different indicates internal coil failure.
If your diagnostic tool offers functional tests, command the rear-right inlet and outlet valves individually to listen and feel for operation. A silent or sticking valve confirms hydraulic unit failure, while normal operation suggests an intermittent wiring issue.
Check for manufacturer technical service bulletins specific to your make and model. Some vehicles have known software updates, connector repair kits, or extended warranties covering specific ABS module failures. Search using your VIN on the automaker's website or the NHTSA database.
Clear the code, complete a test drive that recreates the freeze frame conditions, and verify C1246 does not return. A code that does not recur may indicate a temporary connector issue that reseating the harness resolved.

Repair Options for C1246

C1246 cannot be repaired by replacing external sensors or flushing brake fluid. The fix always involves the ABS hydraulic assembly itself or its wiring.

Replace the ABS hydraulic unit (reman or new): $800–$1,500 parts plus $150–$300 labor
Replace the complete ABS module assembly if the unit is integral to the master cylinder: $1,000–$2,200 total
Repair external wiring harness or connector: $80–$250 depending on whether you splice existing wires or install a connector repair kit

Note that some vehicles allow you to replace only the electronic control module portion of the ABS unit, which sits bolted to the hydraulic unit. This modular approach can reduce costs to $300–$600 for the electronic controller alone.

How Much Does It Cost to Fix C1246?

The total bill depends heavily on your vehicle's ABS design and whether you use dealer, independent shop, or self-installed parts.

ABS hydraulic unit replacement (parts and labor, USD, independent shop rates): $950–$1,800
Electronic ABS controller module only (if separate from hydraulic unit): $300–$600 plus $100–$200 labor
External wiring harness repair or connector replacement: $80–$250

In most cases, C1246 repair falls between $800 and $1,500 when the entire hydraulic unit requires replacement. However, before committing to that expense, verify the external harness thoroughly—connector corrosion or a broken wire in the engine bay costs a fraction of a new ABS unit.

Can You Drive with C1246?

Drive with caution. When C1246 is active, the anti-lock braking system on the right-rear wheel is disabled, and the vehicle reverts to conventional braking without ABS intervention. Standard stopping distances apply, but in rain, snow, or emergency maneuvers, you lose the wheel-lock prevention that helps maintain steering control during hard braking. The regular brake system remains fully functional, so pedal feel and stopping power are not compromised. Avoid aggressive driving until the system is repaired. If the ABS warning light flashes or you notice unusual brake pedal behavior beyond the warning lamp alone, have the vehicle towed rather than driven—additional system faults may be developing simultaneously.