C1207 — ABS Inlet Valve Coil Rear Circuit Open

OBD2 code C1207 flags a problem with the ignition system (ABS inlet valve coil rear circuit open). Short, gentle driving to a shop is usually possible. Common culprits: damaged coil wiring or connector, failed ignition coil or coil pack, moisture or oil in the spark plug wells.

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 C1207 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 Do a continuity test end-to-end on the ABS inlet valve coil rear circuit and wiggle the harness while measuring — intermittent opens show up as fluctuating readings.
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 C1207 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for C1207 (parts and labor, USD, independent shop rates): Replace spark plugs: $90–$250; Replace an ignition coil: $150–$380; Repair coil wiring or connector: $80–$250. Overall, fixing C1207 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

How do I diagnose C1207 myself?

Start with a scan: confirm C1207, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the ABS inlet valve coil rear, and verify the suspect component against live data before buying parts.

How much does it cost to fix C1207?

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

Is it safe to drive with C1207?

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 C1207 clear itself?

Sometimes C1207 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 does OBD2 code C1207 mean?

When your vehicle's control module detects that an electrical circuit has lost continuity where it expects to find a complete path, it logs a diagnostic trouble code to flag the problem. Code C1207 specifically refers to an open circuit condition in the rear ABS inlet valve coil — meaning the module sent voltage to that circuit and received no signal back. The ABS system relies on these inlet valves to modulate brake pressure at each wheel; when the rear inlet valve coil circuit is open, that wheel's anti-lock function is compromised. On most vehicles, the powertrain or chassis control module monitors this circuit continuously, and when the reading falls outside expected parameters across one or more drive cycles, C1207 becomes stored in permanent memory.

The term "circuit open" simply describes a broken electrical path. This could be as straightforward as a severed wire in the harness, a fuse that has blown, or a connector that has come undone or developed corrosion at its pins. Less commonly, the coil itself inside the ABS hydraulic unit can fail internally and create an open circuit condition. Because the module stores a freeze frame alongside C1207 — a snapshot capturing engine speed, load, temperature, and vehicle speed at the moment the fault occurred — technicians can often reproduce those exact conditions during diagnosis and pinpoint the root cause much faster than by guessing.

Common symptoms of C1207

The Check Engine Light or ABS warning lamp illuminates on the instrument cluster.
You may experience harder starting, particularly in damp or rainy conditions.
Fuel economy can drop noticeably during everyday driving.
The engine feels sluggish, and you might notice jerking or hesitation under acceleration.
Cylinder misfires can occur either at idle or under load, sometimes accompanied by a rough running engine.

What causes C1207?

A broken or severed wire within the rear ABS inlet valve coil harness.
A blown fuse that supplies power to the affected circuit.
A disconnected connector, a pin that has backed out of its housing, or significant corrosion at the electrical terminals.
The ABS inlet valve coil itself has failed internally and presents an open circuit.
Worn or incorrectly gapped spark plugs that no longer fire reliably.
Moisture or oil contamination inside the spark plug wells, which can interfere with secondary ignition.
A failed ignition coil or coil pack that no longer delivers sufficient voltage.
Damaged wiring or a deteriorated connector associated with the coil circuit.

How to diagnose C1207

Plug in an OBD2 scanner and verify that C1207 is present in the stored codes. Record the freeze frame data immediately — this snapshot reveals the exact engine conditions present when the module first detected the fault and guides your inspection priorities.
Scan for any additional trouble codes that may be related. Many C-series codes share common grounds or power supplies, and resolving a primary fault often clears secondary codes. Check manufacturer technical service bulletins for your specific make, model, and model year — some C1207 occurrences have known factory fixes or require a module software update.
Perform a thorough visual inspection of the wiring harness and all connectors tied to the ABS inlet valve circuit. Look for chafing, insulation burns, corrosion buildup, or pins that are bent, pushed out, or loose.
Use a multimeter to check continuity end-to-end on the rear ABS inlet valve coil circuit. Gently wiggle the harness during testing; intermittent opens will show as fluctuating resistance readings rather than a clean short or open.
If the vehicle exhibits misfire symptoms, swap the suspect ignition coil to another cylinder and monitor whether the fault code migrates with it — this tells you whether the coil itself is faulty.
Remove and inspect the spark plugs for wear, carbon fouling, oil saturation, or damaged electrodes, and verify that gaps are set to manufacturer specifications.
Clear the code, then drive the vehicle through a complete drive cycle that replicates the conditions recorded in the freeze frame. Confirm that C1207 does not reappear before considering the repair complete.

Repair options and parts costs

Tackle the most common and least expensive possible causes before committing to major component replacement. Spark plug replacement typically runs between $90 and $250 depending on the number of plugs and local labor rates. An ignition coil replacement — if diagnostics confirm the coil is the culprit — generally costs between $150 and $380 for the part and installation. Repairing damaged wiring or a faulty connector in the coil circuit usually falls in the $80 to $250 range depending on whether you need new terminals, a complete connector pigtail, or harness repairs.

The total bill to resolve C1207 will generally fall somewhere between $80 and $380, though the exact figure depends on which component is actually at fault. A proper diagnosis before purchasing parts almost always saves money, because the priciest scenario is rarely the first one to investigate.

Can you drive with C1207?

Treat C1207 with caution. While the vehicle may still operate, the underlying fault can cause cylinder misfires that, if left unaddressed, generate excessive heat and can ultimately destroy the catalytic converter. If your Check Engine Light is flashing rather than steady, stop driving immediately and address the problem before continuing. Even when the light is solid, limit heavy loads and spirited driving until the circuit is restored to proper operation.