Part 1
Planetary gear, animationFunction
To obtain the different gear ratios, the component parts of the planetary gears, such as the sun wheel, planet wheel, ring wheel and planet carrier are locked or released respectively. The friction elements for this are all disc type except for brake B4 which is band type. As there are four different planetary gears, it is possible to obtain a wide range of different ratios.
Planetary gear
1 = S = Sun gear
2 = P = Planet gear
3 = R = Ring gear
Animation
Press "P" to brake the planet carrier, "S" to brake the sun gear and "R" the ring gear. "S+P" will stop the sun gear and the planet gear. Observe the power flow. Pay attention to the direction of rotation with the help of the markings.
Lamp, selector lever position indicator illumination (91)
Location
Lamp, selector lever position indicator illumination (91)
Main use
To illuminate gear position symbols P-R-N-D-M+ and M-
Type
LEDs
Activation
The LEDs are powered by the Shift lever module (726)
Transmission range switch, automatic (245)
Location
Transmission range switch, automatic (245)
Main use
To inform the control module of the engaged gear and via an internal reverse light switch initiate turning on the reversing light and via an integrated starter motor interlock switch to block the starting function.
Type
Mechanical position switch.
Activation
The transmission range switch is a position switch that is powered via +15 from fuse 6 in Rear electric center 342. A number of slip contacts provide the current to the sensor outputs. A combination of terminals A, B, C and PA provide the current selector lever position (see table). The slip contacts can be either closed (ON) or open (OFF).
To ensure the control module receives the correct information, it is essential the sensor be adjusted correctly. Special tool 87 92 467 Adjustment tool, gear selector position sensor must be used when adjusting.
Connecting the gear selector position sensor
Connecting the starter motor interlock switch
Solenoid, selector lever, SHIFT LOCK (439)
Location
Solenoid, selector lever, SHIFT LOCK (439)
Main use
To prevent the selector lever being moved from P or N on automatic cars before the brake pedal has been depressed.
Type
Electromagnetic.
Activation
The solenoid is controlled by the Shift lever module (726). The selector lever can be released manually via the solenoid if there is an electrical fault.
TCM, FA 57 (502a)
Location
TCM, FA 57 (502a)
Main use
Controlling shifting points, system pressure and engagement of lock up.
Type
Microprocessor controlled 10 device, working memory and one programmable EEPROM read memory.
Power supply, ground and bus communication
The control module is powered on pin 33 (A) with +30 voltage and on pins 31 (A) and 22 (A) with +15 voltage. The module is grounded via pins 32 (A) and 23 (A) to grounding point G33T. Bus communication (P-bus) takes place on pins 25-26 (A) and 35-36 (A).
Important
When handling the control module, it is important first to create a ground connection between yourself and for example the vehicle engine. Avoid touching the pins of the control module.
Solenoid valves S1-S5, TCM FA 57 (531)
Location
Solenoid valves, TCM (531)
Main use
To open and close the flow of oil through the valve housing that results in a change of gear ratio.
Type
Electromagnetic.
Activation
The control module activates S1-S5 by making or breaking the circuit to B+. The solenoids are supplied with 0A or 1A from the control module (TCM). Grounding takes place through the solenoid casings.
S1 is supplied from pin 34 (B). The solenoid is hydraulically open when no current is applied.
S2 is supplied from pin 24 (B). The solenoid is hydraulically open when no current is applied.
S3 is supplied from pin 8 (B). The solenoid is hydraulically closed when no current is applied.
S4 is supplied from pin 14 (B). The solenoid is hydraulically open when no current is applied.
S5 is supplied from pin 13 (B). The solenoid is hydraulically closed when no current is applied.
The control module activates the respective valve (S1-S5) for shifting up or down depending on the output speed, accelerator pedal position and the selected driving program.
OFF = 0V, ON = B+
Winding resistance in solenoid S1 is rated 12-16 Ohms at 20° C
Winding resistance in solenoids S2-S5 is rated 11-15 Ohms at 20° C
Diagnostics:
In case of a fault in solenoid S1 fault code P0773 will be generated and the transmission will go into limp-home mode
In case of a fault in solenoid S2 fault code P0753 will be generated and the transmission will go into limp-home mode
In case of a fault in solenoid S3 fault code P0758 will be generated and the transmission will go into limp-home mode
In case of a fault in solenoid S4 fault code P0763 will be generated and the transmission will go into limp-home mode
In case of a fault in solenoid S5 fault code P0768 will be generated and the transmission will go into limp-home mode