Lumbar Support Description and Operation with A45

Lumbar Support Components

The driver seat lumbar support system with memory (A45) consists of the following components:

Lumbar Switch

Battery positive voltage is supplied at all times to the driver seat lumbar switch from the MEM Fuse located in the rear fuse block. When the lumbar switches are pressed they send a 12 volt signal to the MSM. The MSM then commands the lumbar motors to move in response to the switch signals.

Motors

The lumbar support system consists of two motors (horizontal and vertical) that operate independently of each other. The lumbar horizontal motor moves the lumbar support in the forward or rearward directions while the lumbar vertical motor moves the lumbar support in the up or down directions. Each motor contains a electronic circuit breaker (PTC) that opens in the event of a circuit overload and will reset only after voltage has been removed from the circuit. The memory seat module provides each motor with a soft stop that will actually stop the motor just before its physical end-of-travel. This decreases the stress on each motor. If a motor reaches the end-of-travel due a soft stop and the switch is released and pressed again, the lumbar support will move short distance farther to it's physical travel limit.

Horizontal

When the lumbar switch is operated to move the lumbar support forward, battery positive voltage is applied through the switch contacts and the driver seat lumbar forward switch signal circuit to the MSM. In response to this signal, the MSM applies battery positive voltage through the lumbar motor forward control circuit and ground through the lumbar motor rearward control circuit to the motor. The motor runs to drive the lumbar support forward toward the occupant's back until the switch is released. Moving the lumbar support rearward works similarly to moving the lumbar support forward, except that battery positive voltage and ground are applied on the opposite circuits causing the motor to run in the opposite direction. The MSM also controls the lumbar horizontal motor during memory recall functions.

Vertical

When the lumbar switch is operated to move the lumbar support up, battery positive voltage is applied through the switch contacts and the driver seat lumbar up switch signal circuit to the MSM. In response to this signal, the MSM applies battery positive voltage through the lumbar motor up control circuit and ground through the lumbar motor down control circuit to the motor. The motor runs to drive the lumbar support up until the switch is released. Moving the lumbar support down works similarly to moving the lumbar support up, except that battery positive voltage and ground are applied on the opposite circuits causing the motor to run in the opposite direction. The MSM also controls the lumbar vertical motor during memory recall functions.

Position Sensors

The lumbar position sensors are potentiometers which are attached directly to each lumbar motor. The MSM supplies a 5 volt reference voltage through the 5 volt reference circuit and ground through the low reference circuit to each lumbar position sensor. When the lumbar motor rotates, the resistance of the potentiometer varies changing the feedback voltage of the position sensor signal circuit. This voltage varies from 0.25-4.75 volts. The MSM monitors this voltage signal to determine the lumbar position.

When a memory set command is received, the MSM records the lumbar position by storing the feedback voltage from each position sensor. Then, when a memory recall command is received, the MSM moves the motors until the position sensor feedback voltages equals the feedback voltages stored in memory. The lumbar support is not involved in the easy exit function.

Memory Functions

Refer to Memory Seats Description and Operation .

Lumbar Support Description and Operation w/o Memory-A45

Lumbar Support Components

The driver and passenger seat lumbar support systems each consist of the following components:

Lumbar Switch

Battery positive voltage (B+) is supplied at all times to the driver and passenger seat lumbar switches from the PWR SEAT Circuit Breaker located in the rear fuse block. Battery positive voltage (B+) is supplied at all times to the LR and RR passenger lumbar switches from the RR LUM/ANT Fuse located in the rear fuse block. All four lumbar switches are grounded through the switch ground circuits and G 302. The lumbar switches provide both power and ground to the selected lumbar motors.

Motors

The lumbar support system consists of two lumbar motors (horizontal and vertical) that operate independently of each other. Each motor contains an electronic circuit breaker (PTC) that will reset only after voltage has been removed from the motor. The lumbar horizontal motor moves the lumbar support forward and rearward and the lumbar vertical motor moves the lumbar support up and down.

Horizontal

When the lumbar switch is operated to move the lumbar support rearward, battery positive voltage (B+) is applied through the lumbar rearward switch contacts and the lumbar motor rearward control circuit to the lumbar horizontal motor. The motor is grounded through the lumbar forward switch contacts and the lumbar motor forward control circuit to the horizontal motor. The motor runs to drive the lumbar support rearward away from the occupant's back until the switch is released. Moving the lumbar support forward works similarly to moving the lumbar support rearward, except that battery positive voltage (B+) and ground are applied on opposite circuits causing the motor to run in the opposite direction.

Vertical

When the lumbar switch is operated to move the lumbar support up, battery positive voltage (B+) is applied through the lumbar up switch contacts and the lumbar motor up control circuit to the lumbar vertical motor. The motor is grounded through the lumbar down switch contacts and the lumbar motor down control circuit to the vertical motor. The motor runs to drive the lumbar support up until the switch is released. Moving the lumbar support down works similarly to moving the lumbar support up, except that battery positive voltage (B+) and ground are applied on opposite circuits causing the motor to run in the opposite direction.

Lumbar Support Description and Operation Massaging Lumbar-AM3 with Memory-A45

Lumbar Massage Components

The driver massaging lumbar system consists of the following components:

Power Supply

Battery positive voltage is supplied at all times to the lumbar switch through the battery positive circuit and the MEM T&T Fuse located in the rear fuse block. Battery positive voltage is also supplied at all times to the massage module through the battery positive voltage circuit and the PWR SEAT Circuit Breaker located in the rear fuse block. Ground is supplied to the massage module through the module ground circuit and G 302.

Lumbar Vertical Motor

The lumbar vertical motor is reversible. When commanded, it will move the lumbar support in the up and down directions. To protect itself, the motor contains a electronic circuit breaker (PTC) that opens in the event of a circuit overload and will reset only after voltage has been removed from the circuit. The lumbar vertical motor also contains a sensor to monitor the lumbar position. The lumbar vertical motor is controlled by the massage module during massage operation only. During memory recall and manually controlled operations, it is controlled by the MSM.

Massage Operation

When the top of the lumbar switch is momentarily pressed where it is marked AUTO in order to initiate the massage function, battery positive voltage is momentarily applied through the switch contacts and the seat lumbar up switch signal circuit to the massage module. In response to this signal, the massage module then cycles battery positive voltage and ground through the lumbar motor up and down control circuits to the motor. The motor will then continuously move the lumbar support 50 mm in both the up and down directions, and will continuously run this way for 10 minutes or until the lumbar switch is pressed to cancel operation. When massage operation has ceased, the massage module will return the lumbar support to the position from which massage was initiated.

During massage operation, the lumbar horizontal support can be adjusted without interruptions to the massage cycle by operating the lumbar switch in either the forward or rearward directions. However, manually moving the lumbar vertical switch in either the up or down directions will cancel the massage operation and move the lumbar support in the desired direction.

Manual Vertical Movement

When the lumbar switch is operated to move the lumbar support up, battery positive voltage is applied through the lumbar up switch contacts and the lumbar up switch signal circuit to the massage module. In response to this signal, the massage module applies battery positive voltage through the driver seat lumbar up signal circuit to the MSM. The MSM then applies battery positive voltage through the seat lumbar motor up control circuit back to the massage module. The massage module, in turn, applies battery positive voltage through the lumbar motor up control circuit and ground through the lumbar motor down control circuit to the motor. The motor runs in order to drive the lumbar up until the switch is released. When the lumbar switch is operated to move the lumbar down, battery positive voltage is applied through the lumbar down switch contacts and the driver seat lumbar down switch signal circuit to the massage module. In response to this signal, the massage module applies battery positive voltage through the driver seat lumbar down signal circuit to the MSM. The MSM then applies battery positive voltage through the seat lumbar motor down control circuit back to the massage module. The massage module, in turn, applies battery positive voltage through the lumbar motor down control circuit and ground through the lumbar motor up control circuit to the motor. The motor runs to drive the lumbar down until the switch is released. The MSM also controls the lumbar vertical motor through the massage module during memory recall operation.

Position Sensor

The lumbar vertical position sensor is a potentiometer which is attached directly to the lumbar vertical motor it monitors. The MSM supplies a 5 volt reference voltage through the 5 volt reference circuit and ground through the low reference circuit to the lumbar vertical position sensor and the massage module. When the motor rotates, the resistance of the potentiometer varies changing the feed back voltage of the position sensor signal to the massage module. This voltage varies from 0.25 volts to 4.75 volts. During lumbar massage and non-massage operation, the sensor sends this voltage signal through the lumbar vertical position signal circuit to the massage module.

During lumbar massage operation the massage module will output a simulated voltage signal through the lumbar vertical position signal circuit to the MSM. This simulated signal prevents the MSM from seeing the lumbar up/down motion and setting an erroneous diagnostic trouble code (DTC). After massage operation has ceased, the massage module will then update the MSM with the new feed back voltage value. The MSM monitors this feed back voltage to determine the position of the lumbar support for memory set and memory recall functions.

Memory Functions

Refer to Memory Seats Description and Operation .

Lumbar Support Description and Operation Massaging Lumbar-AM3 w/o Memory-A45

Lumbar Massage Components

The massaging lumbar system consists of the following components:

Power Supply

Battery positive voltage is supplied at all times to the lumbar switch and the massage module through the battery positive circuit and the PWR SEAT Circuit Breaker located in the rear fuse block. Ground is supplied to the massage module through the module ground circuit and G 302.

Lumbar Vertical Motor

The lumbar vertical motor is reversible. When commanded, it will move the lumbar support in the up and down directions. To protect itself, the motor contains an electronic circuit breaker (PTC) that opens in the event of a circuit overload and will reset only after voltage has been removed from the circuit. The lumbar vertical motor also contains a sensor to monitor the lumbar position during massage operation. The lumbar vertical motor is controlled by the massage module during manual movement and massage operation.

Massage Operation

When the lumbar switch is momentarily pressed where it is marked AUTO in order to initiate the massage function, battery positive voltage is momentarily applied through the switch contacts and the lumbar motor up switch signal circuit to the massage module. In response to this signal, the massage module then cycles battery positive voltage and ground through the lumbar motor up and down control circuits to the motor. The motor will then continuously move the lumbar support 50 mm in both the up and down directions for 10 minutes or until the lumbar switch is momentarily pressed to cancel the operation. When massage operation has ceased, the massage module will return the lumbar support to the position from which massage was initiated.

During massage operation, the lumbar horizontal support can be adjusted without interruptions to the massage cycle by operating the lumbar switch in either the forward or rearward directions. However, manually moving the lumbar vertical switch in either the up or down directions will cancel the massage operation and move the lumbar support in the desired direction.

Manual Vertical Movement

When the lumbar switch is operated to move the lumbar up, battery positive voltage is applied through the lumbar up switch contacts and the lumbar motor up signal circuit to the massage module. In response to this signal, the massage module applies battery positive voltage through the lumbar motor up control circuit and ground through the lumbar motor down control circuit to the motor. The motor runs in order to drive the lumbar support up until the switch is released. When the lumbar switch is operated to move the lumbar support down, battery positive voltage is applied through the lumbar down switch contacts and the lumbar motor down switch signal circuit to the massage module. In response to this signal, the massage module applies battery positive voltage through the lumbar motor down control circuit and ground through the lumbar motor up control circuit to the motor. The motor runs to drive the lumbar support down until the switch is released.

Position Sensor

The lumbar vertical position sensor is a potentiometer which is attached directly to the lumbar vertical motor. The massage module supplies a 5 volt reference voltage through the 5 volt reference circuit and ground through the low reference circuit to the lumbar vertical position sensor. When the motor rotates, the resistance of the potentiometer varies changing the feed back voltage of the position sensor signal to the massage module. This voltage varies from 0.25 volts to 4.75 volts. The massage module monitors this voltage to determine the vertical position of the lumbar support.