C1980 on 2009-2019 Ford Flex — Adaptive Cruise Control Sensor Blocked
1 vehicles · 1 makes · $300-$2,500 repair
How to diagnose and fix C1980: 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 Flex · 2009–2019
AWD-equipped Ford Flex models suffer from chronic Power Transfer Unit (PTU) seal leaks and eventual PTU failure. The PTU transfers power from the transaxle to the rear driveshaft and is sealed with halfshaft seals that deteriorate over time. When the seals leak, the PTU fluid level drops, causing the unit to overheat and produce metal shavings that destroy the internal gears. Ford issued a TSB acknowledging the problem but never recalled the part. The PTU has no dipstick and the fluid is considered "lifetime" by Ford, meaning most owners never check or change it — leading to premature failure.
Common Symptoms
- Brown or dark fluid leak near the front axle area
- Burning oil smell from under the vehicle after driving
- Grinding or whining noise from the front of the drivetrain
- AWD malfunction warning light or message
- Vibration at highway speeds from the drivetrain
- Metal shavings or black sludge in PTU fluid
How to Fix
Change the PTU fluid every 30,000-40,000 miles regardless of Ford's "lifetime" fluid claim. Have a shop inspect the PTU seals at every oil change for leaks. If the PTU is leaking, replace the seals promptly ($300-$600) before the unit is damaged. If the PTU has already failed (grinding noise, AWD malfunction), replacement costs $1,200-$2,500. An independent transmission shop can flush the fluid at a fraction of the dealer cost.
Sources for this issue (1)
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C1980 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 C1980 mean?
C1980 stands for "Adaptive Cruise Control Sensor Blocked." This is a chassis/safety code indicating the adaptive (radar or smart) cruise control sensor is blocked and cannot see the road ahead clearly. The forward-facing radar or camera that measures the distance and speed of vehicles in front is being obstructed, so the system temporarily disables adaptive cruise and any related collision features. It frequently appears in bad weather or when something physical is covering the sensor. Often it clears once the obstruction is removed.
What are the most common causes of C1980?
The most common causes of C1980 are: Snow, ice, mud, or rain buildup on the sensor or bumper, Dirt, bugs, leaves, or road grime covering the radar, License plate or accessory blocking the sensor, Misaligned radar after a minor impact or bumper work, Sensor needing recalibration after repair or alignment, Faulty radar/camera sensor unit, Damaged wiring or connector to the sensor. The specific cause varies by vehicle.
How much does it cost to fix C1980?
Repair costs for C1980 range from $300 to $2,500, depending on the vehicle and root cause.
Which vehicles are affected by C1980?
Au7o has documented C1980 across 1 vehicle models from 1 manufacturers: Ford.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.