OBD LensOBD Lens App
P1821

Transmission Transfer Case Clockwise Shift Relay Coil Open Circuit

P1821 is described as “Transmission Transfer Case Clockwise Shift Relay Coil Open Circuit” in the Generic OBD2 reference. Other reference families are shown below; select the scope relevant to your vehicle.

Manufacturer reference family

Ford: P1821

en

Transmission Transfer Case Clockwise Shift Relay Coil Open Circuit

Reference namespace
ford
Source revision
legacy-oem-dtc-r2-20260924

Reference family assigned by the production catalog. An entry in this family is not proof of a fault or ECU support on every listed vehicle.

Related catalog brands: Ford.

28 profiles assigned this reference family

4 more related profiles are listed in the vehicle directory.

Manufacturer reference family

GM: P1821

en

Internal Mode Switch Mode "B" Circuit Low

Reference namespace
gm
Source revision
legacy-oem-dtc-r2-20260924

Reference family assigned by the production catalog. An entry in this family is not proof of a fault or ECU support on every listed vehicle.

Manufacturer reference family

Genesis / Hyundai / Kia: P1821

ru

Короткое замыкание на АКБ в проводке насоса для электродвигателя 4WD

Reference namespace
hyundai-kia
Source revision
legacy-oem-dtc-r2-20260924

Reference family assigned by the production catalog. An entry in this family is not proof of a fault or ECU support on every listed vehicle.

Related catalog brands: Kia, Genesis, Hyundai.

401 profiles assigned this reference family

377 more related profiles are listed in the vehicle directory.

Manufacturer reference family

Dodge / Mitsubishi: P1821

en

Transmission Transfer Case Clockwise Shift Relay Coil Open Circuit

Reference namespace
mitsubishi
Source revision
legacy-oem-dtc-r2-20260924

Reference family assigned by the production catalog. An entry in this family is not proof of a fault or ECU support on every listed vehicle.

Related catalog brands: Mitsubishi, Dodge.

31 profiles assigned this reference family

7 more related profiles are listed in the vehicle directory.

Manufacturer reference family

Infiniti / Nissan: P1821

en

Transmission Transfer Case Clockwise Shift Relay Coil Open Circuit

Reference namespace
nissan
Source revision
legacy-oem-dtc-r2-20260924

Reference family assigned by the production catalog. An entry in this family is not proof of a fault or ECU support on every listed vehicle.

Related catalog brands: Nissan, Infiniti.

62 profiles assigned this reference family

38 more related profiles are listed in the vehicle directory.

Generic OBD2

Generic OBD2: P1821

en

Transmission Transfer Case Clockwise Shift Relay Coil Open Circuit

Reference namespace
obd2
Source revision
legacy-2.2.20

Generic OBD2 definition; confirm the protocol and vehicle-specific service information.

Manufacturer reference family

Belgee / Geely / Proton: P1821

en

Transmission Transfer Case Clockwise Shift Relay Coil Open Circuit

Reference namespace
proton
Source revision
legacy-oem-dtc-r2-20260924

Reference family assigned by the production catalog. An entry in this family is not proof of a fault or ECU support on every listed vehicle.

Related catalog brands: Belgee, Geely, Proton.

5 profiles assigned this reference family

What should I check before using this definition?

Keep the full code, module, status and freeze-frame data. Confirm the vehicle’s make, model, year and current manufacturer service information before choosing a repair. This entry does not identify a failed part by itself.

Organize a scan report or recording
Source and applicability

OBD Lens production library legacy-owner-2026-10-09-v81. This is a scoped technical reference, not a scan of your car. A catalog relationship does not certify that every ECU, year or engine returns the same signal or code definition.

Read the reference method

OBD Lens reference library · catalog legacy-owner-2026-10-09-v81. Sources and scope