2010 Cadillac CTS Sedan AWD V6-3.6L Page 185
* Sector switch
* Pawl switch
Action Taken When the DTC Sets
* The liftgate will not power open or manually open.
* The latch may be inoperative or not function normally.
Conditions for Clearing the DTC
* The DTC will be current for as long as the fault is present.
* When the fault is no longer present, the DTC will be a history DTC.
* A history DTC will clear after 50 ignition cycles.
Diagnostic Aids
DTC B153A may be set when the vehicle is driven while the liftgate is open, as when the owner transports a large package in the rear of the
vehicle. The DTC will become history after the liftgate is closed and does not affect normal liftgate operation.
Note: Before testing can be performed on an inoperative liftgate, the liftgate must be opened. Refer to Opening the Liftgate Without Electrical
Power (See: Body and Frame/Doors, Hood and Trunk/Trunk / Liftgate/Service and Repair/Procedures) for the appropriate procedure.
Whenever the LGM loses power or is disconnected, the ignition must be cycled OFF then ON in order to reactivate the LGM.
Reference Information
Schematic Reference
Liftgate Schematics (See: Body and Frame/Locks/Diagrams/Electrical Diagrams/Liftgate Schematics)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Description and Operation
Liftgate Description and Operation (See: Body and Frame/Doors, Hood and Trunk/Trunk / Liftgate/Description and Operation/Liftgate
Description and Operation)
Electrical Information Reference
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit
Testing/Testing for Intermittent Conditions and Poor Connections)
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit Testing/Circuit Testing)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Wiring Repairs/Wiring Repairs)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Connector Repairs/Connector Repairs)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Circuit/System Verification
1. Ignition ON, doors unlocked, transaxle in Park, liftgate closed, disable the power liftgate by pressing the liftgate enable/disable button on the
I/P switch assembly.
2. Observe the scan tool LGM Latch Sector Sw parameter while manually opening the liftgate, the parameter should change from Inactive to
Active to Inactive when opening the liftgate.
3. Observe the scan tool LGM Latch Pawl Sw. and LGM Latch Ratchet Sw. parameters while manually opening the liftgate, the parameters
should change from Inactive to Active.
Circuit/System Testing
1. Ignition OFF, disconnect the X2 harness connector at the LGM.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 3 and ground.
瀚慖f the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the
B+ circuit fuse is open, replace the LGM.
3. Ignition OFF, connect the X2 harness connector at the LGM and disconnect the harness connector at the liftgate latch assembly.
4. Test for less than 10 ohms between the low reference circuit terminal 2 and ground.
瀚慖f greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the LGM.
5. Ignition ON, verify the scan tool LGM Latch Pawl Sw. parameter is Inactive.
