C1778 – OBD-II DTC

OBD-II DTC C1778 – Power Steering Failure

DTC C1778 meaning

DTC C1778 refers to a diagnostic trouble code indicating a power steering failure. This code is specific to the power steering system and suggests that the vehicle’s onboard diagnostic system has detected a malfunction within the power steering control module or its associated components. The power steering system is crucial for providing the driver with the necessary assistance to steer the vehicle, especially at low speeds.

DTC C1778 symptoms

Common symptoms associated with DTC C1778 may include:

• Heavy steering or difficulty turning the steering wheel
• Steering wheel vibrations or unusual noises
• Warning lights illuminated on the dashboard, particularly the power steering or check engine light
• Intermittent power steering assist
• Complete loss of power steering assist

DTC C1778 causes

Several factors can lead to the triggering of DTC C1778, including:

• Faulty power steering control module
• Wiring issues, such as damaged or corroded connectors
• Low power steering fluid levels or fluid leaks
• Defective power steering pump
• Malfunctioning steering angle sensor
• Issues with the vehicle’s battery or charging system

DTC C1778 seriousness

DTC C1778 is considered a serious issue as it directly affects the vehicle’s steering capabilities. Loss of power steering can lead to increased driver fatigue and difficulty maneuvering the vehicle, especially in tight spaces or during low-speed driving. If left unaddressed, it can pose safety risks to the driver and others on the road.

How to diagnose DTC C1778

To diagnose DTC C1778, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the C1778 code.
2. Inspect the power steering fluid level and check for leaks.
3. Examine the wiring and connectors related to the power steering system for damage or corrosion.
4. Test the power steering control module for proper operation.
5. Check the steering angle sensor for functionality.
6. Perform a visual inspection of the power steering pump and its operation.

How to fix DTC C1778 step-by-step instructions

To fix DTC C1778, follow these steps:

1. Address any low power steering fluid levels by topping off or repairing leaks.
2. Repair or replace damaged wiring and connectors associated with the power steering system.
3. If the power steering control module is faulty, replace it with a new unit.
4. Replace the power steering pump if it is found to be defective.
5. Calibrate or replace the steering angle sensor if necessary.
6. Clear the DTC using an OBD-II scanner and test drive the vehicle to ensure the issue is resolved.

How to erase DTC C1778

To erase DTC C1778, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn on the ignition without starting the engine.
3. Navigate to the “Erase Codes” or “Clear DTCs” option on the scanner.
4. Confirm the action to clear the trouble codes.
5. Disconnect the scanner and start the vehicle to verify that the code does not reappear.

Recommended tools for OBD-II diagnostics

Explore our expert picks: The Best OBD2 Scanners for 2025

Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter

Some of the links on this page may be affiliate links, which means we may earn a small commission if you make a purchase. This helps us keep our DTC database up to date and provide valuable content for free. We only recommend products that we have tested and believe to be the best in their class.