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C1990ModerateSafety

C1990 on 2003-2017 Ford Expedition — Forward Collision Warning System Fault

1 vehicles · 1 makes · $300-$1,500 repair

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How to diagnose and fix C1990: most-reported vehicles

Ranked by owner reports. Each card gives the symptoms, how to confirm the cause, the fix, parts and sources for that vehicle.

Ford Expedition · 2003–2017

Community reported
3,800 owners
Link to this issueError Codes:C1725C1726C1727C1728C1990C1991C2002

The 2003-2017 Ford Expedition with optional air suspension (standard on Eddie Bauer, King Ranch, Platinum, and EL/MAX trims) suffers from air suspension compressor failure, air spring leaks, and ride height sensor malfunctions. The compressor, located under the vehicle, is exposed to road debris, salt, and moisture which degrades the motor and valves. When air springs develop leaks, the compressor runs continuously trying to maintain ride height, leading to premature burnout. RepairPal estimates compressor replacement between $666 and $724, though dealer pricing can reach $1,200. NHTSA has received hundreds of complaints regarding air suspension failures. Strutmasters.com notes that 2007-2011 Expedition and Navigator share the same air suspension system and failure patterns. Many owners opt for air-to-coil spring conversion kits as a permanent, lower-cost solution.

Common Symptoms

  • Rear of vehicle sagging or sitting noticeably lower
  • Air suspension warning light or message on dash
  • Compressor runs excessively or continuously
  • Loud compressor noise from under the vehicle
  • Harsh ride over bumps
  • Vehicle leans to one side
  • Hissing sound from air springs or compressor
  • Vehicle bottoming out on speed bumps or driveway transitions

How to Fix

Most cost-effective permanent fix is an air-to-coil spring conversion kit from Strutmasters or Arnott ($300-500 for kit plus installation). If keeping air suspension: replace the compressor (Arnott P-2936 or Dorman 949-200, $200-400 part), both rear air springs ($150-250 each), and inspect all air lines for cracks. Always replace air springs in pairs. Compressor relay should also be checked - a corroded relay causes intermittent compressor operation. RepairPal estimates $666-724 for compressor replacement at a shop.

Typical repair cost:$300 - $1,500
Sources for this issue (1)
  • NHTSA Manufacturer Communications Data Corpusnhtsa

Research This Issue

Based on 3,800 owner reports

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Community Reported
Medium Confidence3,800 owner reportsLast reported by owners Feb 2026Reviewed Feb 2026

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Ford · 1 issue

C1990 code reference

General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.

Frequently asked questions

What does C1990 mean?

C1990 stands for "Forward Collision Warning System Fault." C1990 is a safety-system code indicating a fault in the Forward Collision Warning (FCW) system, which uses a front-facing camera and/or radar to watch for vehicles or obstacles ahead and alert you to a potential crash. The module sets this code when it loses confidence in the system's ability to detect threats reliably, often because a sensor is blocked, misaligned, miscommunicating, or reporting a fault. It generally means the collision-warning (and often automatic emergency braking) features are disabled until repaired. The car still drives normally, but the safety alert function is offline.

What are the most common causes of C1990?

The most common causes of C1990 are: Obstructed radar or camera (ice, snow, mud, dirt, bug debris, sticker), Misaligned front radar sensor or windshield camera after impact or service, Faulty forward-facing camera or radar module, Damaged or corroded wiring/connector to the FCW sensor, Communication (CAN bus) fault between the FCW module and other systems, Low battery voltage or charging-system problem, Windshield replacement without proper camera recalibration, Front bumper or grille damage affecting radar aim. The specific cause varies by vehicle.

How much does it cost to fix C1990?

Repair costs for C1990 range from $300 to $1,500, depending on the vehicle and root cause.

Which vehicles are affected by C1990?

Au7o has documented C1990 across 1 vehicle models from 1 manufacturers: Ford.

Related codes

  • C1991 · Lane Departure Warning System Fault
  • 9062 · Airbag Device Control - Wrong/Incorrect Coding
  • B0100 · Electronic Frontal Sensor 1 Malfunction
  • B0101 · Electronic Frontal Sensor 2 Malfunction
  • B0102 · Electronic Side Sensor Malfunction
  • C1980 · Adaptive Cruise Control Sensor Blocked
  • P2583 · Cruise Control Front Distance Range Sensor Single Sensor or Center
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.

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