Liftgate Release Malfunction (Manual)
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Liftgate Release Malfunction (Manual)
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Diagnostic Fault Information
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Circuit
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Short to Ground
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Open/High Resistance
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Short to Voltage
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Signal Performance
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Liftgate Release Relay B+
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2
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2
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-
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-
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Liftgate Release Switch Signal
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B2494 00
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1
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1
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-
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Liftgate Release Relay Control
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B324A 02
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2
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2
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-
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Liftgate Security Relay Control
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2
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2
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2
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-
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Liftgate Latch Assembly Control
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2
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2
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2
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-
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Liftgate Security Relay Ground
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-
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2
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-
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-
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Liftgate Latch Assembly Ground
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-
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2
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-
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-
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Liftgate Unlatch Switch Ground
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-
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1
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-
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-
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1. Liftgate Release Switch Malfunction
2. Liftgate Release Malfunction
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Circuit/System Description
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The liftgate switch supplies an input to the body control module (BCM). The BCM feeds a voltage to the signal circuit and when the liftgate switch is activated the signal circuit voltage goes low. The BCM controls the liftgate release actuator via the liftgate latch release relay. When the liftgate switch signal is activated, the BCM enables the liftgate release relay by applying battery voltage to the liftgate relay circuit and the relay is energized when the BCM grounds the liftgate release relay control circuit. When the relay is energized battery voltage is supplied to the liftgate latch assembly through the liftgate latch control circuit.
Before testing can be performed the liftgate must be opened. Refer to
Opening the Liftgate Without Electrical Power
for the appropriate procedure.
If the vehicle has a history of the liftgate opening unexpectedly, inspect the point where the wires enter the liftgate unlatch switch for corrosion or evidence of water intrusion.
Schematic Reference
Release Systems Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Liftgate Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References
for scan tool information
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Circuit/System Verification
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1.
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Ignition ON, observe the scan tool Trunk Lid/Liftglass Exterior Unlatch Switch parameter while pressing the S46B liftgate unlatch switch. The reading should change between Active and Inactive.
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2.
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If the value does not change, refer to Liftgate Release Switch Malfunction.
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3.
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Give an UNLOCK command to the liftgate with a scan tool. The A23C liftgate latch unit should release the liftgate.
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4.
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If the A23C liftgate latch assembly does not release the liftgate, refer to Liftgate Latch Malfunction (Except UA2/UTC).
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5.
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If the A23C liftgate latch assembly does not release the liftgate, refer to Liftgate Latch Malfunction (With UA2/UTC).
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Liftgate Release Switch Malfunction
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1.
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Ignition OFF, disconnect the harness connector at the S46B liftgate unlatch switch.
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2.
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Test for less than 5 Ω between the ground circuit terminal 1 and ground.
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3.
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If greater than the specified range, test the ground circuit for an open/high resistance.
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4.
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Ignition ON, verify the scan tool Trunk Lid/Liftglass Exterior Unlatch Switch parameter is Inactive.
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5.
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If not the specified value, test the signal circuit terminal 2 for a short to ground. If the circuit tests normal, replace the K9 BCM.
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6.
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Install a 3 A fused jumper wire between the signal circuit terminal 2 and ground. Verify the scan tool Trunk Lid/Liftglass Exterior Unlatch Switch parameter is Active.
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7.
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If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K9 BCM
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8.
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If all circuits test normal, test or replace the S46B liftgate unltach switch.
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Liftgate Latch Malfunction (Except UA2/UTC)
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1.
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Ignition OFF, disconnect the harness connector at the A23C liftgate latch assembly.
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2.
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Test for less than 5 Ω between the ground circuit terminal 3 and ground.
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3.
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If greater than the specified range, test the ground circuit for an open/high resistance.
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4.
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Connect the harness connector at the A23C liftgate latch assembly.
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5.
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Disconnect the X3 harness connector at the X53A fuse block-rear body.
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6.
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Briefly connect a 15 A fused jumper wire between the control circuit terminal 8 and B+. Verify the A23C liftgate latch assembly activates.
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7.
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If the A23C liftgate latch assembly does not activate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the A23C liftgate latch assembly.
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8.
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Connect a test lamp between the control circuit terminal 21 and ground.
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9.
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Command the liftgate to UNLATCH with a scan tool. The test lamp should illuminate during the unlatch command.
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10.
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If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K9 BCM.
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11.
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If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.
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12.
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Connect a test lamp between the control circuit terminal 12 and B+.
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13.
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Command the liftgate to UNLATCH with a scan tool. The test lamp should illuminate during the unlatch command.
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14.
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If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K9 BCM.
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15.
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If all circuits test normal, replace the X53A fuse block-rear body.
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Liftgate Latch Malfunction (With UA2/UTC)
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1.
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Ignition OFF, disconnect the X2 harness connector at the X53A fuse block-rear body.
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2.
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Test for less than 5 Ω between the ground circuit terminal 27 and ground.
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3.
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If greater than the specified range, test the ground circuit for an open/high resistance.
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4.
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Connect the X2 harness connector and disconnect the X3 harness connector at the X53A fuse block-rear body.
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5.
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Connect a test lamp between the control circuit terminal 21 and ground.
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6.
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Command the liftgate to UNLATCH with a scan tool. The test lamp should illuminate during the unlatch command.
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7.
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If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K9 BCM.
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8.
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If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.
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9.
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Connect a test lamp between the control circuit terminal 12 and B+.
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10.
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Command the liftgate to UNLATCH with a scan tool. The test lamp should illuminate during the unlatch command.
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11.
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If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K9 BCM.
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12.
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Connect the X3 harness connector at the X53A fuse block-rear body and disconnect the harness connector at the A23C liftgate latch assembly.
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13.
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Connect a test lamp between the control circuit terminal 1 and ground.
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14.
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Command the liftgate to UNLATCH with a scan tool. The test lamp should illuminate during the unlatch command.
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15.
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If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the X53A fuse block-rear body.
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16.
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If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the X53A fuse block-rear body.
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17.
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Connect a test lamp between the control circuit terminal 3 and B+.
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18.
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Command the liftgate to UNLATCH with a scan tool. The test lamp should illuminate during the unlatch command.
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19.
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If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the X53A fuse block-rear body.
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20.
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If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the X53A fuse block-rear body.
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21.
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If all circuits test normal, test or replace the A23C liftgate latch assembly.
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Liftgate latch assembly
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1.
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Ignition OFF, disconnect the X1 harness connector at the A23C liftgate latch assembly.
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2.
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Install a 15 A fused jumper wire between the control terminal 1 and 12 V. Momentarily install a jumper wire between the ground terminal 3 and ground. Verify the A23C liftgate latch assembly activates.
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3.
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If the actuator does not perform as specified, replace the A23C liftgate latch assembly.
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Liftgate Release Switch
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1.
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Ignition OFF, disconnect the harness connector at the S46B liftgate unlatch switch.
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2.
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Test for infinite resistance between the signal terminal 2 and the ground terminal 1 with the switch in the open position.
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3.
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If not the specified value, replace the S46B liftgate unlatch switch.
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4.
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Test for less than 2 Ω between the signal terminal 2 and the ground terminal 1 with the switch in the closed position.
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5.
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If greater than the specified range, replace the S46B liftgate unlatch switch.
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Perform the
Diagnostic Repair Verification
after completing the repair.
