SJB Interface

PSD open operation requires the vehicle to be in PARK and the vehicle speed to be less than 5 km/h (3 mph). SJB receives information over the J1850 network from the powertrain control module (PCM) for the PRNDL position and the anti-lock brake system/traction control module (ABS/TC) for the vehicle speed.

If the vehicle is in PARK, the SJB will ground the PARK (enable) circuit to the PSDs. If the vehicle speed is less than 5 km/h (3 mph), the SJB will ground the vehicle speed circuit to the PSDs. As long as these two circuits are at ground, normal PSD open operation can be carried out.

The SJB will prevent PSD open operation if either of these inputs are not grounded. These two inputs to the SJB have network DTCs. If either of these DTCs are retrieved and the PSD is not operating, repair these DTCs first.