C1799 on Jaguar: How to Diagnose & Fix
EPB Hall Effect Sensor Failure (Hall Sensor Plausibility)
1 Jaguar model · 1 documented issue · $500-$1,300 repair
C1799 on Jaguar by model: symptoms, diagnosis and fix
The X150 electronic parking brake is a frequent trouble spot. Small plastic serrated gears inside the EPB motor unit strip, the wiring harness between the parking brake module (PBM) and actuator chafes, and the module/switch can fault. Failures range from a 'Park Brake Fault' warning to the brake staying stuck ON so the car cannot be moved. The plastic gears are not sold separately, so a full motor assembly is usually required.
Common Symptoms
- 'Park Brake Fault' message / EPB warning light
- Parking brake stuck on, car will not move
- Grinding or motor noise from rear when applying/releasing
- Beeping with EPB warning
- Associated DSC / gearbox fault messages
How to Fix
Scan for EPB codes (e.g. C1785 motor interruption, C1799 Hall sensor circuit) and inspect the harness/connectors for chafe and corrosion before condemning parts. Repair typically means replacing the EPB motor/actuator assembly and, where present, the module — the switch is often wrongly blamed. Address a stuck-on brake promptly to avoid dragging pads and rear-caliper damage.
Sources for this issue (2)
C1799 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 C1799 mean on a Jaguar?
C1799 stands for "EPB Hall Effect Sensor Failure (Hall Sensor Plausibility)." The Electronic Parking Brake actuator uses Hall-effect sensors to count motor revolutions so the module can measure cable travel and applied clamp load. C1799 sets when those Hall sensor signals are missing, erratic, or implausible relative to the commanded motor operation, so the module cannot verify how far the actuator has travelled. Like C1785, Jaguar notes this fault is only detectable while the EPB motor is actually running. On Jaguar it is documented across 1 model: XK.
What are the most common causes of C1799?
The most common causes of C1799 are: Failed Hall-effect sensor inside the EPB actuator assembly, Open, shorted or chafed Hall sensor signal / supply wiring to the actuator, Corroded or moisture-contaminated actuator connector (rear underbody exposure), Worn or seized actuator gearbox producing implausible travel counts, Failed EPB control module. The specific cause varies by vehicle.
How much does it cost to fix C1799 on a Jaguar?
Published repair estimates on Jaguar range from $500 to $1,300 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.