Operation
A power open or close cycle can only be initiated from the fully closed or open positions while the vehicle is in park and the liftglass ajar switch input to the liftgate module is inactive. At any time during a power open or close cycle the operation can be reversed by pressing any of the open/close switches. The power liftgate can be switched to manual mode with the on/off switch in the overhead console and during manual operation the power latch will still operate. During power liftgate operation the liftgate module continuously monitors the liftgate position and load profile. The position is calculated from hall effect sensor counts and the electrical load of the gear motor is used to determine physical resistance to the liftgate. Both of these profiles must be learned before the liftgate can operate properly and relearned any time most liftgate components are serviced.
Object Obstruction Detection
The liftgate control module continuously monitors power liftgate operation and calculates its location and direction of travel using 2 hall effect sensors that are part of the gear motor assembly. The hall effect sensors are 3 wire sensors and are supplied with a 5 volt power circuit, ground and signal circuits from the liftgate control module. The hall effect sensor signal circuits are referenced from battery voltage within the liftgate control module and pulsed low by the hall effect sensors.
The power liftgate system uses a secondary object detection method which consists of object sensors fixed to both sides of the liftgate near the seal area. The object sensors consist of an internal fixed resistor and normally open switch contacts which when closed will bypass the resistor. The signal circuit is supplied 5 volts through a resistor and monitored within the liftgate control module, and during normal power liftgate operation the signal circuit should remain a fixed value. When an object presses one of the sensors the contacts close and the resistor is bypassed causing the signal circuit voltage at the module to go low.
Gear Motor Assembly
The liftgate motor is a bi-directional motor and open or close operation is the result of the direction of the motor rotation. The liftgate module controls the liftgate motor through the control circuits by suppling power and ground in the appropriate polarity. The motor control circuits are monitored by the liftgate module prior to activation for a high or low condition and during motor operation for any irregular current flow conditions.
The liftgate motor clutch engages or disengages the liftgate motor to the liftgate drive gear and is the component that determines power or manual operation. When the liftgate module supplies power to the clutch control circuit the clutch coil is energized and the liftgate motor is engaged to the liftgate drive gear so that power operation can occur. The liftgate module monitors the clutch control circuit at all times for a short high while in an inactive state or a short low or insufficient current flow while in an active state.
The full open switch is part of the gear motor assembly and will close and become active when the liftgate reaches the full open position. The full open switch signal circuit is supplied battery voltage through a resistor and monitored within the liftgate module. The liftgate provides a low reference circuit and when the switch contacts close the signal circuit goes low and the liftgate module determines the switch to be active.
DTC B153A 00: Liftgate Latch Switch Signal Circuit
DTC B153A 08: Liftgate Latch Switch Signal Circuit Signal Invalid
When calibrating the liftgate position, the liftgate module (LGM) is placed in a functional state to learn the liftgate travel limits. DTC B1019 00 will set automatically as an indicator that the system is in learn mode and not as a fault indicator. Once the travel limits are learned by the liftgate module, the LGM will exit calibration mode. If the LGM does not exit learn mode, DTC B1019 00 will remain current and indicate a fault.
DTC B153B 02: Liftgate Open Switch Signal Circuit Short to Ground
DTC B153B 05: Liftgate Open Switch Signal Circuit Short to Short to Battery or Open
DTC B153E 02: Liftgate Position Sensor Signal Circuit Short to Ground
DTC B153E 05: Liftgate Position Sensor Signal Circuit Short to Battery or Open
DTC B153E 08: Liftgate Position Sensor Signal Circuit Signal Invalid
Your best bet , take it to the dealer .
DTC B153F 02: Liftgate Object Sensor Signal Circuit Short to Ground
DTC B153F 03: Liftgate Object Sensor Signal Circuit Voltage Below Treshold
DTC B153F 05: Liftgate Object Sensor Signal Circuit Short to Battery or Open
DTC B153F 07: Liftgate Object Sensor Signal Circuit Voltage Above Threshold
Do you know what diagnostic trouble codes are .Checking codes should be the first step to diagnose this problem . Probably a shorted sensor . Factory scan tool is need to check for these codes
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SOURCE: BMW remote control problem
I have a e60 525i that I just brought and it has the same problem, the owners manual suggests driving with the key in the ignition for a long time as the batteries are rechargable and may have gone flat, i have tried this and it doesnt seem to work
i also read something about getting water in the aerial about the rear window and that wrecks the receiever. My car isn;t under warranty so not looking forwarding to taking it to bmw
SOURCE: display console
There is a switch in the lift gate latch that closes when the gate is closed and turns off the light, this switch is defective, replace it and the light will go off.
SOURCE: 98 4Runner rear window no longer operates
Open the rear hatch. Pull off the inner trim panel. Look to see if there is a little box with a bunch of wires connected to it. It may be at the lower edge, driver side. Turn the key on. Test for 12 volts at the solid BLUE wire (there is only 1 solid blue wire) that is connected to the box. Is there power? If not, check the 30 amp POWER fuse. If there IS power, this box may be bad. This is the power window relay for the rear hatch. The wiper/washer and the rear window motor power all come out of this box.
BUT:
Check for power & get back to me before you buy a relay box, there are a few other tests I could share with you before we pronounce the relay box bad...
SOURCE: 07 GMC Yukon liftgate will open, but not close automatically
Check on the Strut Assembies on Each side of the Door. There should be a Safety device on them that will allow you to keep the door up, They could be Catching at the Open Position.
SOURCE: automatic sliding doors and lift gate don't always work
You need to go to the dealer and have them check the codes. The factory has a reflash for the sliding door and liftgate modules for this type of problem the codes it might have for this is INCOMPLETE POWER OPEN - EXCESSIVE HALL EFFECT SIGNAL the flash is resetting obstacle detection values. But you need to go to the dealer, this can be only one possible cause. I have fixed many vans that has had these 2 codes. There is a bulletin from chyrsler for this.
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