2010 Cadillac CTS Sedan AWD V6-3.6L Page 374

2010 Cadillac CTS Sedan AWD V6-3.6L Page 374

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 Descriptor

DTC B1420 02

- Device Voltage Short To Ground

Diagnostic Fault Information

Circuit/System Description

The liftgate control module controls operation of the liftgate latch motor and the liftgate actuator assembly. Under normal conditions the power

latch can only be unlatched under power from the liftgate control module through an input from the liftgate handle switch, the driver door switch,

or the remote keyless entry transmitter, but the liftgate may be manually closed to the primary latched position without the liftgate control module

performing the power latch function. The ON/OFF switch in the driver door will enable or disable the power open/close operation of the actuator

assembly but will have no effect on power latch operation. The drive motor is mated to a worm type gear off the actuator clutch and when the

clutch is engaged the motor rotation is transferred to the clutch gear, intermediate gear, and actuator arm gear. The liftgate control module

continuously monitors power liftgate operation and calculates its location and direction of travel using 2 inputs from the liftgate position sensor.

One input returns the position of the liftgate relative to the latch along the x-axis and the other returns the position of the liftgate relative to the latch

along the y-axis. The liftgate control module then uses these 2 inputs together to calculate its angle relative to the liftgate latch.

Conditions for Running the DTC

Battery voltage must be less than 9 volts or greater than 15.9 volts.

Conditions for Setting the DTC

* The supply voltage to the liftgate control module is less than 9V.

* The conditions above must be present for more than 5 seconds

Action Taken When the DTC Sets

The power liftgate will be inoperative.

Conditions for Clearing the DTC