Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC C1984 Brake Maintenance Mode: Trouble Symptom
2016 Subaru Legacy 2.5iSECTION Trouble Symptom
Parking brake system does not operate.
DIAGNOSTIC PROCEDURE
| Step | Check | Yes | No |
|---|---|---|---|
| 1 CHECK ELECTRONIC PARKING MODE. | Is the brake maintenance mode in progress? | Currently, it is normal. This DTC is stored when the brake maintenance mode is in progress. < Ref. to BRAKE MAINTENANCE MODE , MAINTENANCE MODE, VDC Control Module and Hydraulic Control Unit (VDCCM & H/U). > DTC will be cleared when the maintenance mode is finished by following the procedure. | Go to step 2 . |
2 CHECK OPERATION OF ELECTRONIC PARKING BRAKE.
|
Is DTC stored even though the electronic parking brake operates? | Replace the VDCCM & H/U. < Ref. to VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM & H/U) . > | Go to step 3 . |
| 3 CHECK DETECTION OF OTHER DTCS FOR VDC. < Ref. to READ DIAGNOSTIC TROUBLE CODE (DTC) . > |
Is any other DTC displayed? | Perform the diagnosis according to DTC. < Ref. to LIST OF DIAGNOSTIC TROUBLE CODE (DTC) . > Perform the diagnosis from step 1 again, and if the same DTC is stored, replace the VDCCM & H/U. < Ref. to VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM & H/U) . > | Currently, it is normal. Temporary interference from noise is a possible cause. |
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.