841004482 - E3077 FRONT HEAD RESTRAINT ADJUSTMENT OPERATIONAL DESCRIPTION

Operational Description

Driving position control unit M076 is supplied by two lines: one to pin B8 of connector C via service relay R21 and fuse F56 of boot junction unit B045 (used to supply the drive motors), the other to pin C7 of connector C via a line protected by fuse F69 of B045.Service relay R21 is activated from a signal from boot control unit M063 (pin 24 of connector F), which enables (via the B-CAN network) movement of the various loads even during the timed period (one minute) following Key-off.The boot control unit is supplied by a line protected by fuse F61 of control unit B045. The front driver side control unit H066 is connected to connector B of driving position control unit M076 that supplies the various motors to determine their movements:

  • from pin B5 to pin A4 for head restraint height adjustment via motor N131 (from pins B8 and A7 of connector B);
  • from pins A3 and C3 for storage/recall of the three ride positions.
Driving position control unit M076 maintains the three head restraint positions in the memory by means of a potentiometer (inside the engine unit) that supplies its own analogue return signal to pin B3 of connector B.Memory store is indicated by a buzzer inside instrument panel E050 via a signal received on the B-CAN network at pins 3 and 4 of connector A.Front passenger seat head restraint movements are determined by a different operating strategy. Control unit H067 governs operation of motor N134 directly from pins B6 and B7.Body Computer M001 receives a car speed signal from braking system control unit M051 at pin 7 of connector A: if this speed exceeds 10 Km/h, the Body Computer (pins 5 and 7 of H) inhibits any motion (automatic and/or manual) of the driver side seat via the B-CAN network. Driving position control unit M076 downloads this condition via the C-CAN network at pins A4 and B3 of connector C.Body Computer M001 receives an INT/A (key-on) signal from ignition switch H001 at pin 27 of connector D via fuse F31 of underfacia control unit B002.