2010 Cadillac Truck SRX AWD V6-3.0L Page 235
Component Testing
1. Ignition OFF, disconnect the harness connectors at the B71 liftgate object sensor.
2. Test for 8k-12k ohm between the signal terminal A and the low reference terminal B.
瀚慖f not within the specified range, replace the B71 liftgate object sensor.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the repair.
* Liftgate Side Upper Sensor Replacement (See: Body and Frame/Doors, Hood and Trunk/Trunk / Liftgate/Trunk / Liftgate Position
Sensor/Service and Repair/Liftgate Side Upper Sensor Replacement)
* Control Module References (See: Testing and Inspection/Programming and Relearning) for liftgate control module replacement, setup and
programming
B154A
DTC B154A or B154B
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions)provides an overview of each diagnostic category.
DTC Descriptors
DTC B154A 39
- Driver Mirror Internal Malfunction
DTC B154B 39
- Passenger Mirror Internal Malfunction
Circuit/System Description
The outside rearview mirror switch is a multiplex switch which signals the left mirror control module which outside rearview mirror to move
(driver or passenger) and which direction to move it. The left mirror control module and the passenger window switch are on a serial data circuit
with the memory seat module as the master. The mirror select and directional control switches are inputs to the left mirror control module. When
the memory seat module receives the switch inputs from the left mirror control module, mirror output commands are sent to the appropriate switch
through the serial data circuit. The left mirror control module and passenger window switch control the left and right outside rear view mirrors
through bi-directional motor control circuits. The motor control circuits are floating while in an inactive state and the switches will apply power and
ground to the control circuits as necessary to move the mirror in the commanded direction.
Mirror position is determined by both horizontal and vertical position sensors in each of the power mirrors. The left mirror control module and
passenger window switch supply a 5 V reference, low reference, and horizontal and vertical position signal circuits to these sensors. The signal
circuits are referenced from 5 V by the switches and the signal circuit voltage levels represent the mirror positions. The mirror positions are sent to
the memory seat module through the serial data circuit where they are stored for memory mirror operation. When the memory seat module receives
a memory recall command, the memory seat module will send the go to position commands to the left mirror control module and passenger window
switch. The switches will then drive the appropriate mirror motors to the commanded position sensor settings.
Conditions for Running the DTC
Battery voltage must be between 9-16 V.
Conditions for Setting the DTC
B154A 39
The left mirror control module has determined that a hardware or software error has occurred.
B154B 39
The passenger window switch has determined that a hardware or software error has occurred.
