C1933 — Solenoid Current Out Of Range

OBD2 code C1933 flags a problem with the sensor and actuator circuits (solenoid current out of range). The car is usually drivable while you plan the repair. Common culprits: open or shorted wiring in the circuit, blown fuse feeding the circuit, poor ground connection.

chassis (brakes/steering/suspension)

Is it safe to drive?

Short-term driving is OK In most cases the car remains drivable, possibly with reduced performance or a disabled auxiliary system. If symptoms include stalling, no-start or brake/steering warnings, treat it as urgent.

How to diagnose with an OBD scanner

Read the code and freeze frame Connect an OBD2 scanner, confirm C1933 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 solenoid current out of range for damage, corrosion, chafing or poor contact.
Subsystem check Measure reference voltage, ground and signal continuity at the component connector.
Subsystem check Wiggle-test the harness while watching the signal in live data — dropouts reveal broken wires.
Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm C1933 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for C1933 (parts and labor, USD, independent shop rates): Repair wiring or connectors: $80–$250; Control module repair: $300–$1,000; Replace the faulty sensor or actuator: $150–$500. Overall, fixing C1933 usually costs between $80 and $1,000. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

What is the most common cause of C1933?

The most common causes are: open or shorted wiring in the circuit, blown fuse feeding the circuit, poor ground connection.

How much does it cost to fix C1933?

Repair wiring or connectors — $80–$250; Control module repair — $300–$1,000; Replace the faulty sensor or actuator — $150–$500. Exact cost depends on the root cause, your vehicle and local labor rates — a proper diagnosis is the cheapest first step.

Will C1933 clear itself?

Sometimes C1933 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.

How do I diagnose C1933 myself?

Start with a scan: confirm C1933, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the sensor and actuator circuits, and verify the suspect component against live data before buying parts.

What does OBD2 code C1933 mean?

When your vehicle's control module detects that a solenoid circuit is drawing current outside its expected range, it logs code C1933. This trouble code lives in the chassis systems category, which means it typically involves brakes, steering, or suspension components rather than the engine itself. The module constantly monitors the electrical behavior of these circuits, watching for signs that a solenoid is behaving abnormally — either pulling too much current, too little, or none at all.

C1933 doesn't trigger from a single glitch. The on-board diagnostics require the fault to appear repeatedly under specific driving conditions before illuminating the check engine light. This matters because when the code sets, the module also captures a freeze frame snapshot: engine load, RPM, coolant temperature, and vehicle speed at the moment the problem occurred. That data is your roadmap for recreation during diagnosis.

The underlying system here is the solenoid circuit itself. Solenoids are electromechanical devices — essentially coils of wire that create magnetic fields when current flows through them. In vehicle applications, they control things like hydraulic valves in braking systems, shift solenoids in transmissions, or suspension damping actuators. When the module sends a command and the resulting current doesn't match expectations, C1933 sets.

Symptoms of C1933

The check engine light or traction warning lamp illuminates on the dashboard
The affected system may enter limp-home mode, restricting full functionality
Some drivers notice higher fuel consumption when a related system operates inefficiently
The controlled component — whether a valve, actuator, or solenoid — works intermittently or stops responding entirely
In rare cases, braking or steering feel different until the fault clears

Common Causes

Wiring in the solenoid circuit has an open break or a short to ground/battery voltage
Corrosion, loose pins, or damaged connectors create high resistance at the harness junction
The solenoid coil itself has failed internally, causing current draw to fall outside specifications
A blown fuse or fusible link interrupts power to the affected circuit
The control module's driver circuit — the transistor that actuates the solenoid — has failed internally
Poor chassis ground prevents proper current return, confusing the module's measurements

How to Diagnose C1933

Connect an OBD2 scanner and confirm C1933 is currently stored. Record all freeze frame data and any pending or permanent codes that accompanied it — related codes often point to the root cause faster than the primary code alone.
Check manufacturer technical service bulletins using your exact make, model, and model year. Search the NHTSA database or your brand's owner website with your VIN. Some C1933 faults have documented software patches or known harness routing updates from the factory.
Perform a thorough visual inspection of the wiring harness and connectors associated with the fault circuit. Look for wire chafing from road debris, connector body cracks, water intrusion signs, or pins that have backed out of their housings. This step alone resolves most C1933 cases.
At the solenoid connector, measure reference voltage, ground circuit resistance, and signal wire continuity with a multimeter. Compare readings against manufacturer specifications. A voltage drop exceeding a few hundred millivolts indicates a problem worth fixing.
With the connector still attached, monitor live data on your scanner while gently wiggling the harness. Any signal dropout, spike, or code reappearance pinpoints the wire location that needs repair.
After repairs, clear the code and complete a full drive cycle — especially under the conditions recorded in the freeze frame. The code must stay cleared; if it returns, the root cause is still present.

Repair Options and Costs

The right repair depends entirely on what your diagnosis reveals. Labor rates vary by region, but these estimates reflect typical independent shop pricing in the United States.

Wiring harness repair or connector replacement: $80–$250. Often the fix when chafed wires or corroded pins are found. Soldering or weatherpack connector replacement falls in this range.
Control module driver repair or replacement: $300–$1,000. This becomes necessary when the module itself cannot properly drive the solenoid circuit. Some modules can be rebuilt; others require sourcing a used or refurbished unit.
Faulty sensor or actuator replacement: $150–$500. When the solenoid coil has internally shorted or open-circuited, replacing the component itself is the permanent fix.

Most shops charge $75–$125 per hour for diagnostic time, so getting a precise diagnosis before purchasing parts makes financial sense. The $80–$1,000 total range reflects everything from a simple harness repair to a full control module replacement.

Driving Safety Verdict

Severity: short. In most vehicles, C1933 does not prevent driving — you can reach a repair facility without immediate risk. However, if the fault affects braking feel, causes stalling, triggers a no-start condition, or produces steering warnings, treat it as urgent and have the vehicle towed rather than risk a safety incident.