C1921 – OBD-II DTC

OBD-II DTC C1921 – VAPS Solenoid Actuator Output Circuit Failure

DTC C1921 meaning

DTC C1921 refers to a fault in the Vehicle Active Suspension System (VAPS) related to the solenoid actuator output circuit. This code indicates that the powertrain control module (PCM) has detected an issue with the electrical circuit that controls the solenoid actuator responsible for adjusting the vehicle’s suspension settings. The solenoid actuator plays a crucial role in maintaining optimal ride quality and handling by adjusting the suspension based on driving conditions.

DTC C1921 symptoms

Common symptoms associated with DTC C1921 may include:

• Warning light illuminated on the dashboard
• Unusual ride quality or handling characteristics
• Increased body roll during cornering
• Suspension system may be stuck in one setting
• Possible noise from the suspension components

DTC C1921 causes

Several factors can lead to the occurrence of DTC C1921, including:

• Faulty solenoid actuator
• Wiring issues such as shorts, opens, or corrosion in the circuit
• Defective connectors or terminals
• Malfunctioning powertrain control module (PCM)
• Software issues within the PCM

DTC C1921 seriousness

DTC C1921 is considered a moderate to serious issue. While the vehicle may still be operable, the compromised suspension system can lead to poor handling and ride quality, which may affect safety. It is advisable to address this code promptly to ensure optimal vehicle performance and safety.

How to diagnose DTC C1921

To diagnose DTC C1921, follow these steps:

1. Use an OBD-II scanner to confirm the presence of DTC C1921.
2. Inspect the wiring and connectors related to the solenoid actuator for any visible damage or corrosion.
3. Check the solenoid actuator for proper operation using a multimeter.
4. Test the power and ground circuits to the solenoid actuator.
5. Examine the PCM for any software updates or faults.
6. Clear the DTC and perform a road test to see if the code reappears.

How to fix DTC C1921 step-by-step instructions

To fix DTC C1921, follow these steps:

1. Inspect and repair any damaged wiring or connectors related to the solenoid actuator.
2. Replace the solenoid actuator if it is found to be faulty.
3. Ensure all connections are secure and free of corrosion.
4. Check the PCM for any necessary software updates and reprogram if needed.
5. Clear the DTC using an OBD-II scanner.
6. Perform a road test to confirm that the issue has been resolved and the DTC does not reappear.

How to erase DTC C1921

To erase DTC C1921, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn the ignition key to the “On” position without starting the engine.
3. Access the DTC menu on the scanner and locate DTC C1921.
4. Select the option to clear or erase the DTC.
5. Turn off the ignition and disconnect the scanner.
6. Start the vehicle and monitor for any reoccurrence of the code.

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