C1726 on Ford: How to Diagnose & Fix
Steering Torque Sensor Signal Invalid
1 Ford model · 1 documented issue · $300-$1,500 repair
C1726 on Ford by model: symptoms, diagnosis and fix
The 2003-2017 Ford Expedition with the optional air suspension 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. Compressor replacement typically costs $666-$724, though dealer pricing can reach $1,200. 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
The 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. Shop compressor replacement typically runs $666-724.
Sources for this issue (2)
C1726 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 C1726 mean on a Ford?
C1726 stands for "Steering Torque Sensor Signal Invalid." C1726 is a steering/chassis code indicating the steering torque sensor is sending an invalid or implausible signal. On electric power steering (EPS) systems, the torque sensor measures how hard you're turning the wheel so the system knows how much assist to provide. When the EPS module receives a signal that's out of range, erratic, or doesn't agree with its internal checks, it flags the data as invalid. It generally results in reduced or lost power-steering assist (heavier steering), with a steering or EPS warning light, even though the car remains steerable. On Ford it is documented across 1 model: Expedition.
What are the most common causes of C1726?
The most common causes of C1726 are: Faulty steering torque sensor, Wiring or connector fault in the torque sensor circuit, Loss of or unstable sensor reference/supply voltage, Corrosion or moisture in the steering column connectors, Torque sensor not calibrated/initialized after service, Internal EPS module fault, Low battery voltage affecting sensor operation. The specific cause varies by vehicle.
How much does it cost to fix C1726 on a Ford?
Published repair estimates on Ford range from $300 to $1,500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
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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.