P1828 Code: Meaning, Causes, and Symptoms | OBD2 Codes

P1828 – Transmission Transfer Case Counter Clockwise Shift Relay Coil Circuit Failure

 

P1828 Possible Symptoms

 

Engine Light ON (or Service Engine Soon Warning Light)

 

P1828 Possible Causes

 

Faulty Generic Electronic Module (GEM),Generic Electronic Module (GEM) harness is open or shorted,Generic Electronic Module (GEM) circuit poor electrical connection

 

P1828 Description

 

The transfer case is equipped with an electromagnetic clutch which is located inside the case. This clutch is used to spin up the front driveline when shifting from 2WD to 4H mode at speed. When the control switch on the instrument panel is turned, the Generic Electronic Module (GEM) recognizes that a shift has been requested and activates the electromagnetic clutch and the relays which power the transfer case shift motor. When the shift motor reaches the desired position, as determined by the contact plate position inputs to the GEM, power to the shift relays and motors will be removed. When the transfer case front and rear output shafts are synchronized, the spring loaded lockup collar mechanically engages the mainshaft hub to the drive sprocket.Finally, the front axle collar is engaged and the electromagnetic clutch is deactivated. The transfer case clutch relay is an electromechanical relay used to activate the transfer case clutch within the transfer case.