This bulletin applies to 2019-2022 Honda Passport with AWD, 2016-2022 Pilot with AWD and 2017-2022 Ridgeline with AWD vehicles. The AWD warning light may be on. One or more of the following DTCs may have been set:

-          C1841-27 (differential temp sensor 1 circuit)

-          C1842-27 (differential temp sensor 2 circuit)

-          C1850-12 (right side pressure sensor circuit high voltage)

-          C1851-87 (F-CAN malfunction lost communication)

-          C1851-96 (functional abnormalities of differential pump)

-          C1855-92 (differential motor low speed)

A possible cause is water intrusion into the rear differential pump motor connector  area, causing terminal corrosion. If these DTCs are present and water intrusion is verified, replace the rear differential pump motor and rear subframe sub-harness.