C1898 — Steering VAPS II Circuit Loop Open #

Note: The description for DTC C1898 may differ depending on the vehicle manufacturer (OEM). Always refer to your OEM service manual for the most accurate information.

• Steering VAPS II Circuit Loop Open (Ford, Lincoln, Mercury)
• Variable Assist Power Steering II Circuit Open (Mazda)
• Steering Assist Control Circuit Open (Jaguar, Land Rover)

Summary of DTC C1898 #

DTC C1898 is a diagnostic trouble code that indicates the vehicle’s Variable Assist Power Steering (VAPS) II circuit has an “open loop” condition. In simple terms, this means the electronic circuit controlling variable steering assist isn’t completing its path, preventing proper communication or power transfer. VAPS is a system that dynamically adjusts power steering assistance based on vehicle speed—offering more assist at low speed and firming up at higher speeds for stability. When this circuit is open, the system reverts to a default or failsafe mode, which can alter steering feel and response. Prompt attention is recommended, as steering performance and safety may be affected.

Common Symptoms for C1898 #

When C1898 is present, you may notice changes in how your steering feels, especially during parking or highway driving. The system is designed to make steering lighter at low speeds and firmer at higher speeds, so an open loop can make the steering feel unusual or inconsistent. Be aware of these typical symptoms:

• Steering feels heavier than normal at low speeds, such as during parking maneuvers.
• Warning light illuminated on the dashboard (Steering or Service Power Steering).
• Loss of variable steering assist—steering effort does not change with speed.
• Possible intermittent or total loss of power steering assist in rare cases.
• Unusual noises from the steering system (less common).

Most Likely Causes of C1898 #

The C1898 code is most often triggered by electrical faults in the VAPS II system. These can range from simple wiring issues to failed electronic components. Here are the most common causes, in order of likelihood:

1. Open or damaged wiring in the VAPS II circuit harness.
2. Loose, corroded, or disconnected electrical connectors at the steering module or related sensors.
3. Faulty VAPS II actuator or motor (the device that changes steering assist).
4. Defective steering control module (the “brain” of the VAPS system).
5. Blown fuse or relay for the VAPS system.
6. Internal failure in the steering rack assembly (rare).

Step-by-Step Diagnosis for C1898 #

A methodical approach is essential for accurately diagnosing C1898. Rushing or skipping steps can lead to unnecessary parts replacement or continued issues. Here’s a structured process to follow:

• Consult OEM wiring diagrams for the VAPS II system to identify all related components and circuits.
• Visually inspect wiring and connectors for signs of damage, corrosion, or disconnection. Pay close attention to areas near the steering column and rack.
• Check for blown fuses or faulty relays related to the power steering or VAPS system.
• Test for continuity in the VAPS II circuit using a multimeter. An “open” reading indicates a break in the wire or poor connection.
• Scan for additional codes that may provide context (such as communication or related steering codes).
• Test the VAPS II actuator or motor for correct operation (refer to OEM test procedures).
• Check the steering control module for proper power, ground, and signal inputs/outputs.
• If all else checks out, consider possible internal faults within the steering rack assembly.

Possible Repairs for C1898 #

Repairs for C1898 should address the root cause found in diagnosis, not just clear the code. Common solutions include:

• Repair or replace damaged wiring in the VAPS II circuit.
• Clean or reseat loose connectors and ensure proper fitment.
• Replace faulty VAPS actuator/motor if it fails operational tests.
• Install a new steering control module if diagnosed as defective (may require programming).
• Replace blown fuses or relays identified during checks.
• Address internal steering rack faults if confirmed (rare and typically last resort).

Is It Safe to Drive with C1898? #

Limited use only. While C1898 is not an immediate “stop driving” code, it does mean your variable steering assist isn’t working as intended. You may notice heavier steering at low speeds or less precise control at higher speeds. For short, careful trips—such as driving to a repair shop—it may be acceptable. However, extended driving, especially in challenging conditions, is not recommended. Always prioritize safety and address the issue promptly.

Vehicles Most Commonly Affected by C1898 #

C1898 is most frequently reported on certain Ford, Mazda, Jaguar, and Land Rover models equipped with variable assist power steering. OEM systems and naming conventions may vary, but these vehicles often use similar technologies:

• Ford Explorer, Expedition, Taurus (various years)
• Lincoln Navigator, MKS
• Mazda 6, CX-9 (with VAPS option)
• Jaguar XF, XJ (with steering assist)
• Land Rover Range Rover (select models)

Common Mistakes & Best Practices for C1898 #

Technicians and DIYers sometimes make avoidable errors when addressing C1898. Being mindful of these can save time and money:

• Replacing components without a full diagnosis—always check wiring and connectors first.
• Overlooking intermittent wiring faults—wiggle test harnesses to reveal hidden breaks.
• Forgetting to check for software updates—some steering modules may need reprogramming after repair.
• Ignoring related codes—other DTCs can provide valuable clues.
• Not following OEM procedures—always consult the service manual for specific test values and steps.

Quick FAQ for C1898 #

Here are answers to a couple of the most common questions about C1898:

• Q: Will clearing the code fix the problem?
  A: No. Clearing the code will temporarily turn off the warning light, but the underlying issue will cause the code to return unless properly repaired.
• Q: Can C1898 cause steering to fail completely?
  A: Complete steering failure is rare, but loss of variable assist can make the vehicle harder to steer—especially at low speeds. Address the issue as soon as possible.