GF91.29-P-0009CEA Electrical Seat Adjustment (ESA)
GF91.29-P-0009CEA Electrical Seat Adjustment (ESA)
MODEL 204.0 /2
- with CODE (275) Memory package (driver seat, steering column, mirrors)
- with CODE (242) Electrically adjustable front passenger seat with memory
as of model year 2009 /YoM 08
MODEL 204.3
- with CODE (275) Memory package (driver seat, steering column, mirrors)
- with CODE (242) Electrically adjustable front passenger seat with memory
MODEL 204.9
- with CODE (275) Memory package (driver seat, steering column, mirrors)
- with CODE (242) Electrically adjustable front passenger seat with memory
A1 Instrument cluster
M27/1 Driver seat fore/aft adjustment motor
M27/2 Driver seat height adjustment motor
M27/3 Driver seat inclination adjustment motor
M27/4 Driver seat head restraint adjustment motor
M27/5 Driver seat backrest inclination adjustment motor
M28/1 Passenger seat longitudinal adjustment seat adjustment motor (with code (242) Electrically adjustable passenger seat with memory)
M28/2 Front passenger seat height adjustment seat adjustment motor (with code (242) Electrically adjustable passenger seat with memory)
M28/3 Front passenger seat inclination adjustment seat adjustment motor (with code (242) Electrically adjustable passenger seat with memory)
M28/4 Head restraint adjustment seat adjustment motor, front passenger seat (with code (242) Electrically adjustable front passenger seat with memory)
M28/5 Front passenger-seat seat backrest inclination seat adjustment motor (with code (242) Electrically adjustable passenger seat with memory)
N10/2 Rear SAM control unit with fuse and relay module
N32/1 Driver seat control unit
N32/2 Front passenger seat control unit (with code (242) Electrically adjustable front passenger seat with memory)
N69/1 Left front door control unit
N69/2 Right front door control unit
N73 Electronic ignition switch control unit
S22 Left front seat adjustment switch group
S22s6 Left front memory function switch
S22s7 Left front memory 1 switch
S22s8 Left front memory 2 switch
S22s9 Left front memory 3 switch
S23 Right front seat setting switch group (with code (242) Electrically adjustable front passenger seat with memory)
S23s6 Right front memory function switch (with code (242) Electrically adjustable front passenger seat with memory function)
S23s7 Right front memory 1 switch (with code (242) Electrically adjustable front passenger seat with memory function)
S23s8 Right front memory 2 switch (with code (242) Electrically adjustable front passenger seat with memory function)
S23s9 Right front memory 3 switch (with code (242) Electrically adjustable front passenger seat with memory function)
S54/5 Left rear backrest inclination switch (model 204.0/3 with code (287) Through-loading feature, model 204.2/9)
S54/6 Right rear backrest inclination switch (model 204.0/3 with code (287) Through-loading feature, model 204.2/9)
S54/7 Left rear backrest lock switch (model 204.0/3 with code (287) Through-loading feature, model 204.2/9)
S54/8 Right rear backrest lock switch (model 204.0/3 with code (287) Through-loading feature, model 204.2/9)
S159/3 EASY-ENTRY system limit switch, driver seat (model 204.3)
S159/4 EASY-ENTRY system limit switch, front passenger seat (model 204.3)
CAN B Interior CAN
LIN B5 Left door LIN
LIN B6 Right door LIN
Function requirements, general
^ No engine start (circuit 50 Off)
^ No undervoltage (U < 9.3 V)
The electronic ignition lock control unit sends the circuit status and the on-board electrical system voltage over the interior CAN.
Electrical seat adjustment (ESA), general
The ESE enables the electrical adjustment of the driver seat and with code (242) Electrically adjustable front passenger seat with memory, plus the front passenger seat. The driver and front passenger seat can be adjusted as follows:
- Seat fore/aft position
- Backrest angle
- Seat height
- Seat inclination
- Head restraint height
Moreover, it is possible to store and move to the particular seat position.
On the driver-side, the positions of the outside mirrors and the steering column are also stored and retrieved via the memory function.
The ESA includes the following subfunctions:
^ Function sequence for manual adjustment
^ Function sequence for saving and retrieving seat positions
^ Function sequence for head restraint presetting
^ Normalization function sequence
^ Function sequence for position measurement
^ Function sequence for antilock device
^ Fault handling function sequence
^ Function sequence for rear easy entry (model 204.3)
^ Function sequence for collision avoidance with rear bench seat (model 204.0/3 with code (287) Through-loading feature, model 204.2/9)
Function sequence for manual adjustment
The manual adjustment function comprises the following subfunctions:
^ Function sequence for manual adjustment of driver seat
^ Function sequence for manual front passenger seat adjustment (with code (242) Electrically adjustable front passenger seat with memory)
^ Priorities
Function sequence for manual adjustment of driver seat
The manual adjustment is operated via the left front seat adjustment switch group. The left front seat adjustment switch group is read in over the left door LIN by the left front door control unit. The left front door control unit sends the requests from the left front seat adjustment switch group to the driver seat control unit via interior CAN. For the adjustment, the switches in the left front seat adjustment switch group must be held down until the desired position is reached.
The driver seat control unit actuates the following motors directly corresponding to the request:
- Driver seat fore/aft adjustment motor
- Driver seat height adjustment motor
- Driver seat inclination adjustment motor
- Driver seat head restraint adjustment motor
- Driver seat backrest inclination adjustment motor
Function sequence for manual front passenger seat adjustment (with code (242) Electrically adjustable front passenger seat with memory)
The manual adjustment is operated over the right front seat adjustment switch group. The right front seat adjustment switch group is read in over the right door LIN by the right front door control unit. The right front door control unit sends the requests from the right front seat adjustment switch group to the front passenger seat control unit via interior CAN. For the adjustment, the switches in the right front seat adjustment switch group must be held down until the desired position is reached.
The front passenger seat control unit actuates the following motors directly corresponding to the request:
- Front passenger seat fore/aft adjustment motor
- Front passenger seat height adjustment motor
- Front passenger seat inclination adjustment motor
- Front passenger seat head restraint adjustment motor
- Front passenger seat backrest inclination adjustment motor
Priorities
The seat adjustment is divided up into 2 groups and 3 priorities.
Each adjustment in a group is independent from an adjustment in another group.
If several adjustment requests are received in a group by the driver seat control unit, then the adjustment request with the higher priority is executed.
The priorities are determined as follows:
Group 1
- High priority, backrest angle
- Average priority, head restraint height
- Low priority, seat inclination
Group 2
- High priority, seat fore/aft position
- Average priority, seat height
Additional function requirements for saving and retrieving seat positions
^ ESE normalized
Function sequence for saving and retrieving seat positions
The save/retrieve seat positions function is comprised of the following subfunctions:
^ Function sequence for saving and retrieving seat positions, driver seat
^ Function sequence for saving and calling up front passenger seat positions (with code (242) Electrically adjustable front passenger seat with memory)
Function sequence for saving and retrieving seat positions, driver seat
There are two button operation options for storing the seat position:
- Hold down left front memory function switch and then press left front memory switch 1, left front memory switch 2 or left front memory switch 3 for the corresponding memory location.
- Press left front memory switch function for t > 100 ms. Press left front memory switch 1, left front memory switch 2 or left front memory switch 3 within 0.2 s less than or equal to t less than or equal to 3 s for the corresponding memory location.
The status of the switches is read in via the left door LIN and transmitted to the driver seat front door control unit via the interior CAN. The driver seat control unit stores the current position of the seat.
To actuate the stored position, press left front memory switch 1, left front memory switch 2 or left front memory switch 3 until the desired end position is reached. Releasing leads to immediate termination of the adjustment procedure.
Function sequence for saving and calling up front passenger seat positions (with code (242) Electrically adjustable front passenger seat with memory)
There are two button operation options for storing the seat position:
- Hold down right front memory function switch and then press right front memory switch 1, right front memory switch 2 or right front memory switch 3 for the corresponding memory location.
- Press right front memory switch function for t > 100 ms. Press right front memory switch 1, right front memory switch 2 or right front memory switch 3 within 0.2 s less than or equal to t less than or equal to 3 s for the corresponding memory location.
The status of the switches is read in via the right door LIN by the right front door control unit and transmitted over the interior CAN to the front passenger seat control unit. The front passenger seat control unit stores the current position of the seat.
To actuate the stored position, press right front memory switch 1, right front memory switch 2 or right front memory switch 3 until the desired end position is reached. Releasing leads to immediate termination of the adjustment procedure.
Successful storage of the seat position is confirmed by the instrument cluster with an acknowledgment tone.
Abort conditions:
Moving to a stored position is interrupted during:
- Manual seat adjustment
- Manual mirror adjustment (only driver)
- Manual steering column adjustment (driver only)
- When pressing an additional memory switch
Additional function requirements for head restraint presetting
^ Normalized seat fore/aft position
^ Normalized head restraint height
Function sequence for head restraint presetting
The height of the head restraint is automatically preset by the driver seat control unit or by the front passenger seat control unit depending on the seat fore/aft position. If the seat is moved forward, the head restraint moves down. If the seat is moved rearward, the head restraint moves up. The head restraint is adjusted in stages.
The head restraint presetting function can be switched on and off in the driver seat control unit or the front passenger seat control unit using the diagnosis and is coded country-specifically using the Software Calibration Number (SCN).
Additional function requirements for normalization
^ Circuit 15R ON
Normalization function sequence
Normalization is important for the assignment of the absolute adjustment position and the position recorded by the driver seat control unit. Normalization must be performed during initial start-up or in a denormalized condition.
To carry out the normalization procedure, it is necessary to move to the following mechanical end stops:
- Front end stop of seat fore/aft position and backrest angle
- Down-stop of seat inclination, seat height and head restraint height
For normalization, the corresponding switch in the seat adjustment switch group must remain actuated for t = 250 ms after the mechanical end stop has been reached.
Upon successful normalization, the driver seat control unit or the front passenger seat control unit switches off the corresponding seat adjustment motor. The normalization procedure should be performed via diagnosis for initial start-up. For this, circuit 15R must be switched on.
An adjustment is denormalized if the signal of the corresponding Hall sensor is not received. The Hall sensors are allocated to the particular adjustment motors. The denormalization procedure can also be performed via diagnosis.
Function sequence for position measurement
The seat adjustment motors are equipped with Hall sensors. The signals from the Hall sensors are read in and evaluated by the driver seat control unit or the front passenger seat control unit.
Function sequence for antilock device
If a defective Hall sensor is detected for t > 2 s, the corresponding adjustment function is switched off by the driver seat control unit or the front passenger seat control unit after t = 2 s.
Reactivation in the same adjusting direction is not permitted until the corresponding switch has been released for approx. t greater than or equal to 2 s.
Re-enabling in the opposite adjustment direction is immediately possible.
Fault handling function sequence
The driver seat control unit or the front passenger seat control unit checks the requests for seat settings it has received for plausibility. Adjustment requests for the same adjustment function in an opposite direction (e.g. backrest angle forward//back simultaneously) are rejected. Correct requests for other adjustment functions remain unaffected.
The plausibility of a manual adjustment request for a memory setting is checked by the left front door control unit or the right front door control unit.
Additional function requirements for rear easy-entry (model 204.3)
^ associated vehicle door open or
^ Circuit 15R or
^ Circuit 15 ON and vehicle speed below v = 5 km/h
If, during the process, the function conditions are canceled, the head restraint movement continues until it is completed.
Furthermore, the function is only started when no abort conditions are pending.
The precondition for the function is that the head restraint adjustment was normalized at the upper stop.
Function sequence for rear easy entry (model 204.3)
By pulling the backrest release handle mechanically, the front seat backrest is released and can then be folded forward. When unlocking, the backrest release contact switch in the EASY-ENTRY system limit switch is actuated, which is read in by the driver seat control unit or by the front-passenger control unit. Then the head restraint moves to the lower stop to prevent collision with the headliner.
When folding the backrest forward from the non-actuated state, the seat inclination switching contact in the EASY-ENTRY system limit switch is actuated, which is read in by the driver seat control unit or the front passenger seat control unit. The front seat then starts moving forward. If, during moving forward, the backrest is folded back, the front seat moves back again.
The excess force limiter is active during forward movement of easy-entry. If pinching is recognized, the seat reverses toward the rear, however, only up to the rear EASY-ENTRY end position at maximum.
By pulling the backrest release handle, the backrest is unlocked in the front-most position and can be folded back; in doing so, the backrest release contact switch in the EASY-ENTRY system limit switch is actuated. When folding back the backrest from the non actuated state, the seat inclination contact switch is actuated. The front seat then starts moving backward. The backrest returns to the initial position and locks in the folded-back position. If the backrest is folded forward again during backward motion, the front seat again moves toward the front.
When the easy-entry function moves backward, the excess force limiter is active. If pinching is recognized, the seat reverses toward the front but not beyond the front end position of easy entry. After locking the backrest and reaching the initial position of the seat fore/aft adjustment, the initial positions of the head restraint and the seat cushion length, height adjustment and inclination are actuated again. Here the priorities observed according to the group category.
The left EASY-ENTRY system limit switch consists of two contact switches, backrest inclination switch contact switch and backrest release contact switch.
The driver seat control unit or the front passenger seat control unit monitors whether the backrest is correctly locked and, if necessary, sends a signal to the instrument cluster when vehicle speed is v = 6 km/h to initiate a corresponding warning display.
Abort conditions:
The easy-entry function is interrupted, when the Hall sensor for the head restraint is detected as defective
Additional function requirements for collision avoidance with rear bench seat (model 204.0/3 with code (287) Through- loading feature, model 204.2/9)
^ Normalization of seat fore/aft adjustment, height adjustment and backrest adjustment performed
^ Vehicle speed less than v = 5 km/h
^ Circuit 15 Off (driver seat only)
Function sequence for collision avoidance with rear bench seat (model 204.0/3 with code (287) Through-loading feature, model 204.2/9)
If the rear seat backrest is unlocked, this is detected by the rear SAM control unit through the left rear backrest lock switch and the right rear backrest lock switch. The backrest inclination in the rear is detected by the rear SAM control unit over the left rear backrest inclination switch and the right rear backrest inclination switch.
The rear SAM control unit then sends a signal over the interior CAN to the driver seat control unit or to the front passenger seat control unit.
The driver seat control unit and front passenger seat control unit evaluate the current seat adjustment and detect whether a collision hazard with the front seat is present when folding down the rear backrest. If a collision hazard with the driver or front passenger seat is given when folding down the rear backrest and rear seat, the driver seat control unit and front passenger seat control unit start the following measures:
- The driver or front passenger seat is moved forward if it is positioned too far to the rear (seat fore/aft adjustment)
- The driver or front passenger seat backrest is raised if it is inclined too far (backrest adjustment)
- The driver or front passenger seat is moved up if it is positioned too far down (seat height adjustment)
If the seat adjustment has been set in front of these particular positions, an adjustment towards the rear with the rear seat backrest unlocked is only possible up to these respective set positions (with code 494 USA version).
- If the rear seat backrest is locked again, the seat remains on its current position. It is not returned automatically to the initial position.
- The seat fore/aft adjustment is possible when the rear seat backrest is locked over the entire adjustment range.
Abort conditions:
This function is aborted in the event of:
- Locking the rear backrest
- Actuating left front seat adjustment switch group
After interruption of the function, the driver or front passenger seat including on vehicles with code (494) USA version, can be adjusted without limitation.
In vehicles with code (494) USA, it possible to adjust to the collision zone during the collision avoidance function with the rear seat bench. The seat adjustment is coded following installation depending on the country.
The rear SAM control unit monitors through the left rear backrest lock switch and the right rear backrest lock switch, whether the rear backrest is correctly locked and, if necessary, it sends a signal to the instrument cluster to display a corresponding warning message.
To trigger the collision avoidance with the rear seat function again, the system must detect that the rear backrest has been locked again.
