C1785 on Jaguar: How to Diagnose & Fix
EPB Motor Output Open Circuit
1 Jaguar model · 1 documented issue · $500-$1,300 repair
C1785 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)
C1785 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 C1785 mean on a Jaguar?
C1785 stands for "EPB Motor Output Open Circuit." The Electronic Parking Brake (EPB) module drives the parking brake actuator motor and monitors current flow on its output. C1785 sets when the module commands the motor to run but sees an open circuit on the motor output — no current path — so the actuator cannot be driven. Jaguar documentation notes this fault can only be detected while the EPB motor is running, i.e. during an apply or release cycle. On Jaguar it is documented across 1 model: XK.
What are the most common causes of C1785?
The most common causes of C1785 are: Open or broken EPB motor output wiring between module and actuator (common at the rear harness / underbody routing), Corroded or water-intruded EPB actuator connector, Failed EPB actuator motor (open windings or worn brushes), Failed EPB control module output driver, Blown EPB motor fuse. The specific cause varies by vehicle.
How much does it cost to fix C1785 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.
Looking for C1785 on a different make?
View C1785 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.