Electric seats

The BCU can be programmed to operate the electric seats according to one of three options:

• Option 1 - no electric seats.
• Option 2 - normal.
• Option 3 - operates with ignition only.

To determine when to provide an output to the passenger and drivers seat enable relay, the BCU checks the condition of the following inputs:

• Ignition state.
• Transit mode.
• Driver's door open.

The electrically controlled seats are operated when the ignition switch is in position I or II or for a predetermined period when the driver's door is open. If the ignition state is in crank, the seat enable relay is off. If the ignition state is off and the driver's door open input is off, the seat enable relay is off. If the ignition state is off and the driver's door open input is on and transit mode is on, the seat enable relay output is off.

The power supply to each seat switch pack is powered from a power seat relay located on the underside of each seat frame. The feed from the relay is protected by a fuse located in a satellite fuse block located adjacent to the power seat relay. The fuse block also contains two additional fuses which are used to protect the feeds to the lumbar pump and solenoid.

With the ignition switch in position I or II or the driver's door open, the BCU provides an earth path for the coils of the LH and RH power seat relays, energizing the relays and closing the contacts. If the driver's door input signal is on for longer than 45 seconds with the ignition switched off, the seat enable relay is switched off.