C1A04 on Nissan: How to Diagnose & Fix
Front Right Height Sensor Fault
1 Nissan model · 1 documented issue · 1 critical · $250-$1,800 repair
C1A04 on Nissan by model: symptoms, diagnosis and fix
Multiple owners of the current B18-generation Sentra report the Forward Collision Warning and Automatic Emergency Braking systems triggering warnings or braking unexpectedly, sometimes with no vehicle or obstacle present. This is a safety-critical issue because false braking or loss of collision mitigation can increase crash risk in traffic.
Common Symptoms
- Automatic emergency braking activates unexpectedly
- Warning chime with no obstacle ahead
How to Fix
Scan the ADAS system for stored faults, inspect the front radar sensor mounting and alignment, and check for contamination, impact damage, or harness issues. Owners should also verify that any applicable software updates or service campaigns have been completed.
Owner tips & cautions
- TipKeep the front radar area clean and inspect for minor bumper damage or misalignment after even light impacts; many owners report intermittent faults after parking-lot contact.
Sources for this issue (3)
C1A04 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 C1A04 mean on a Nissan?
C1A04 stands for "Front Right Height Sensor Fault." C1A04 is a manufacturer-specific chassis code (documented on Nissan/Infiniti applications) indicating a fault with the front-right height sensor. This sensor measures ride height at the front-right corner and feeds systems such as auto-leveling suspension or automatic headlight aiming. When the module sees an invalid or out-of-range signal, the dependent feature is disabled and a warning may appear. Because it is a manufacturer code, confirm the exact application against the factory service manual. On Nissan it is documented across 1 model: Sentra.
What are the most common causes of C1A04?
The most common causes of C1A04 are: Faulty front-right height sensor, Damaged sensor link/arm or mounting, Damaged or corroded wiring/connector, Water intrusion at the connector, Poor ground or low supply voltage, Suspension/leveling control module fault. The specific cause varies by vehicle.
How much does it cost to fix C1A04 on a Nissan?
Published repair estimates on Nissan range from $250 to $1,800 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.