B1820 - FAULT CODE - OBD2

B1820 BUICK, CADILLAC, CHEVROLET, GMC: DRIVER SEAT RECLINE REARWARD SWITCH CIRCUIT SHORT TO BATTERY

When pressing one of the power seat switches, a 12-volt signal is sent through the signal circuits to the Memory Seat Module (MSM). Then, the MSM tells the driver’s seat motors to move to the required position in response to the signals sent by the switch.

OBD2 fault code B1820 is set when a battery short is discovered in the driver’s seat rearward recline switch circuit.

• The Check Engine light turns on.
• The task of reclining the driver's seat may not be carried out successfully.

Reasons to set the B1820 OBDII diagnostic code:

• The wires related to the driver's seat adjustment switch may be damaged.
• The driver's seat adjustment switch circuit may be faulty in its connections.
• The driver's seat adjustment switch may be faulty.
• The Memory Seat Module may be in bad condition.

To troubleshoot DTC B1820 OBD2, consider this:

• See TSBs.
• Check the wiring involved with the driver's seat adjustment switch circuit. Look for deficiencies caused by burns or wear. If such conditions are discovered, make repairs.
• Using the necessary tools, perform electrical checks on the driver's seat adjustment switch circuit. Verify if the voltages of this circuit are within the values established by the manufacturer. If you discover inconsistencies that could cause the battery to short out, make the appropriate adjustments.
• Check the condition of the driver's seat adjustment switch. Before replacing the switch, consider that the failure is not due to electrical deficiencies.