C1274 — Solenoid Relay # 1 Circuit Failure

What is the most common cause of C1274?

The most common causes are: control module driver fault, poor ground connection, faulty sensor or actuator of the affected circuit.

What does OBD2 code C1274 mean?

C1274 — Solenoid Relay # 1 Circuit Failure. A fault in the sensor and actuator circuits. The car is usually drivable while you plan the repair. Typical causes: control module driver fault, poor ground connection, faulty sensor or actuator of the affected circuit.

What are the symptoms of C1274?

Drivers most often notice: Check Engine Light on, the affected system operates intermittently or not at all, increased fuel consumption in some cases, possible limp mode depending on the affected component.

Is it safe to drive with C1274?

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 do I diagnose C1274 myself?

Start with a scan: confirm C1274, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the solenoid relay # 1 circuit, and verify the suspect component against live data before buying parts.

When your scanner displays C1274, the vehicle's control unit has identified that the first solenoid relay circuit is behaving outside its designed parameters. The fault description reads "Solenoid Relay # 1 Circuit Failure," and because this code lives in the chassis category, it usually ties to anti-lock braking, steering assist or suspension control rather than the powertrain itself.

The module watches this circuit in real time while you drive. When sensor or actuator signals stay outside the acceptable range for a set number of drive cycles, the ECU logs C1274 and turns on the warning light. The stored freeze frame data captures the exact conditions at the moment of failure — engine speed, load, coolant temperature and vehicle speed. That snapshot tells you what was happening when the fault occurred, which is invaluable for recreating the problem during testing.

C1274 essentially means the relay that controls a specific solenoid has lost communication with the control module, has an electrical short or open, or is receiving incorrect voltage. The underlying cause could be as simple as a corroded connector or as serious as an internal module fault.

Symptoms of C1274

• The Check Engine or ABS warning light stays on
• The affected system runs intermittently or stops working entirely
• Some drivers notice higher fuel consumption
• The vehicle may enter limp-home mode, limiting power or disabling certain features
• In rare cases, braking or steering feel abnormal if the fault involves a safety-critical circuit
• No other drivability symptoms appear in milder cases

Common Causes of C1274

• Damaged wiring or loose connectors in the solenoid relay # 1 circuit
• A failed sensor or actuator on the monitored circuit
• Blown fuse feeding power to the relay circuit
• Weak or corroded ground connection at the component
• Faulty control module driver that manages the relay
• Water or contamination entering the connector, causing short circuits
• Aftermarket accessories shorting the circuit (less common)

How to Diagnose C1274

1. Plug in an OBD2 scanner, confirm C1274 is stored and record the freeze frame data. That information shows engine conditions when the fault appeared, giving you specific test conditions to replicate.
2. Look at all other stored codes. Related fault codes often point to the real root cause. Also check manufacturer TSBs for your make and model — some C0xxx issues have known factory solutions or software updates.
3. Inspect the wiring harness and connectors for solenoid relay # 1 by hand. Pull back loom tape, look for broken insulation, green corrosion, bent pins or anything that looks out of place.
4. Test the circuit with a multimeter: verify reference voltage, confirm clean ground and check signal continuity at the component connector. Compare readings to factory specifications.
5. Perform a wiggle test while monitoring live data on the scanner. Any signal dropouts during movement suggest a broken wire or intermittent connector.
6. Clear C1274, drive the vehicle through the conditions captured in the freeze frame data and verify the code does not return. If it comes back, the fault is confirmed and not an intermittent glitch.

Repair Options and Costs

Tackle the least expensive possibilities before replacing major components:

• Wiring repair or connector replacement: $80–$250
• Replace faulty sensor or actuator: $150–$500
• Control module repair or replacement: $300–$1,000

The total cost to fix C1274 varies widely depending on which part is actually at fault. Independent shop rates in the United States typically put the full repair bill between $80 and $1,000. Most of the time the problem lives in the wiring or connectors, so start there before committing to a costly module repair.

Can You Drive with C1274?

The vehicle generally remains drivable when C1274 is active. You may notice reduced performance, a disabled辅助系统 or an illuminated warning lamp. If the fault causes stalling, a no-start condition or affects braking and steering, treat it as urgent and stop driving immediately. Otherwise, schedule diagnosis and repair at your earliest convenience — do not ignore a repeated failure.