C1922

What Does Code C1922 Mean?

DTC C1922 signifies an “Output Circuit Open” condition within the Variable Assist Power Steering (VAPS) Solenoid Actuator circuit. This code indicates that the Powertrain Control Module (PCM), or in some architectures, a dedicated Power Steering Control Module (PSCM) which reports to the PCM, has detected an open circuit when attempting to command the VAPS solenoid actuator. The VAPS system is designed to provide varying levels of power steering assist based on vehicle speed and other parameters, offering maximum assist for low-speed maneuvering and reduced assist at higher speeds for improved road feel and stability. The solenoid actuator is an electro-hydraulic valve that modulates hydraulic fluid flow or pressure within the power steering system to achieve this variable assist. When the control module commands the solenoid to activate, it monitors the current draw or voltage drop across the circuit. An “open circuit” means the module is not detecting the expected current flow or continuity, implying a break or high resistance somewhere in the electrical path to or within the solenoid itself. This typically results in the VAPS system defaulting to a fixed, often minimal, assist level for safety, negating the variable assist functionality.

Common Symptoms

• Increased Steering Effort at Low Speeds: The most prevalent symptom, as the system fails to provide adequate assist during parking or slow-speed maneuvers.
• Steering Feels “Heavy” or “Stiff”: A general perception of increased resistance when turning the steering wheel, regardless of speed, indicating a loss of variable assistance.
• Lack of Steering Effort Variation: The driver may notice that the steering feel does not change appropriately with vehicle speed, remaining consistently heavy.
• Power Steering Warning Light: While C-codes typically do not illuminate the Malfunction Indicator Lamp (MIL), a specific power steering system warning light may be activated on the instrument cluster.

What Causes the Code C1922?

• Faulty VAPS Solenoid Actuator: An internal open circuit or broken winding within the solenoid itself, preventing current flow when commanded.
• Open Circuit in Wiring Harness: A broken wire or severe chafing within the power or ground control circuit leading to the VAPS solenoid actuator.
• Corrosion or Damage in Electrical Connectors: Compromised pins, corrosion, or improper seating in the connectors for the VAPS solenoid or the control module, leading to an intermittent or complete open circuit.
• Blown Fuse (if applicable): While less common for an “output circuit open” unless the fuse powers only the solenoid and not other components, a blown fuse in the solenoid’s supply circuit could cause this.
• Faulty Power Steering Control Module (PSCM) or Powertrain Control Module (PCM): An internal fault within the driver circuit for the VAPS solenoid within the control module (less common than external circuit faults).

How to Diagnose and Troubleshoot

Diagnosing C1922 requires systematic electrical testing:

1. Retrieve and Analyze DTCs: Use an OBD-II scanner to confirm C1922 is the primary code and check for any related or accompanying codes (e.g., communication faults if a separate PSCM is present). Note any freeze-frame data.
2. Visual Inspection: Disconnect the battery. Carefully inspect the VAPS solenoid actuator and its associated wiring harness for any obvious signs of damage, chafing, cuts, or corrosion. Check the integrity of the electrical connectors at the solenoid and the control module (PCM/PSCM). Ensure the power steering fluid level is correct, though this is less directly related to an open circuit.
3. VAPS Solenoid Actuator Resistance Test:
   • Locate the VAPS solenoid actuator, typically mounted on the power steering pump or steering rack.
   • Disconnect its electrical connector.
   • Using a Digital Multimeter (DMM) set to ohms, measure the resistance across the two terminals of the solenoid itself.
   • Refer to the vehicle-specific service manual for the expected resistance value (typically a few ohms to several tens of ohms, e.g., 8-20 Ohms).
   • If the DMM displays “OL” (Open Line) or an extremely high resistance, the VAPS solenoid actuator is internally open and requires replacement.
4. Wiring Harness Continuity and Voltage Tests:
   • With the solenoid disconnected, identify the power and ground/control wires for the VAPS solenoid at the connector, using a wiring diagram.
   • Power Supply Test: Reconnect the battery. With the ignition ON, use the DMM set to DC volts to check for battery voltage (B+) or a switched 12V supply at the appropriate pin of the solenoid’s harness connector. If no voltage is present, trace the wire back to its source (fuse box, PCM/PSCM) to find the open circuit or power supply issue.
   • Continuity to Ground/Control Module: Disconnect the battery again. Use the DMM set to continuity or ohms. Test the continuity of the ground or control wire from the solenoid connector back to its respective pin at the PCM/PSCM connector. An “OL” or very high resistance indicates an open circuit in the wiring.
   • Continuity to Power Source: Similarly, test the continuity of the power wire from the solenoid connector back to its power source (e.g., fuse or PCM/PSCM).
   • If any continuity test fails, meticulously trace the affected wire to locate the break or high resistance point.
5. Control Module Output Test (Advanced):
   • If the solenoid and wiring test good, the issue might be with the control module’s internal driver.
   • Using a scan tool capable of active tests, command the VAPS solenoid ON and OFF while monitoring the voltage or current output on the control wire at the PCM/PSCM connector (with the solenoid disconnected). A DMM or oscilloscope can be used.
   • If the module fails to provide the commanded output, it may be faulty.

Recommended Repairs and Solutions

The repair strategy directly follows the diagnostic findings:

• Replace VAPS Solenoid Actuator: If the solenoid tests as internally open, replace the entire VAPS solenoid actuator. This often involves working on the power steering pump or steering rack, requiring proper fluid handling and bleeding procedures post-replacement.
• Repair or Replace Wiring Harness: If an open circuit is identified in the wiring, repair the damaged section using appropriate automotive-grade wire, soldering techniques, and heat-shrink tubing to ensure a durable and waterproof connection. For extensive damage, replacing the entire harness section might be more practical.
• Clean or Repair Connectors: If corrosion or poor contact at the connectors is the cause, thoroughly clean the terminals with electrical contact cleaner and a small brush. For bent or damaged pins, attempt to carefully straighten them or replace the connector housing and terminals if necessary. Apply dielectric grease to the terminals upon reassembly to prevent future corrosion.
• Replace Fuse: If a blown fuse was identified as the culprit, replace it with a fuse of the correct amperage. Investigate why the fuse blew, as it could indicate a short elsewhere in the circuit that might have led to the initial open condition.
• Replace PCM/PSCM: If all other components and wiring have been thoroughly tested and confirmed good, and the control module’s driver for the VAPS solenoid is definitively found to be faulty, the control module will require replacement. This is typically a dealer-level repair, as new modules often require programming or “flashing” to the specific vehicle.

Mechanic’s Tips: Always consult the vehicle-specific service manual for exact component locations, wiring diagrams, and specified resistance values. After any repair involving the power steering system, ensure the system is properly bled to remove air, which can cause noise and impaired function. Clear the DTCs after repairs and perform a thorough road test at varying speeds to confirm the VAPS system is functioning correctly and the C1922 code does not return.