B1942
B1942 - Power Liftgate Position Sensor 2 Circuit Performance
For a complete wiring diagram, refer to
Theory of Operation
The power liftgate position sensor is located inside the power drive unit. It provides two signals which informs the module of the true position of the liftgate. These signals (sensors 1 and 2) can be read on the scan tool and are displayed as True and False. The sensors are supplied 5 volts from the power liftgate module. As the liftgate is in motion, the sensors will toggle between 5.0 volts and 0.02 volts.
• When Monitored: Whenever the power liftgate is power opening or closing.
• Set Condition: When the power liftgate module senses the position sensor signal 2 circuit not pulsing during motor operation, this code will set.
Test Step 1 - DTC Present
• With the scan tool, record DTCs.
• Erase DTCs.
• Turn the ignition OFF, wait 10 seconds, then turn the ignition ON.
• If possible, operate the liftgate several times.
• With the scan tool, check for DTCs.
Does the scan tool display B1942 - Power Liftgate Position Sensor 2 Circuit Performance?
Yes
• Go to Test Step 2
No
• Using the wiring diagram/schematic as a guide, inspect the wiring and connectors for an intermittent condition.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior
Test Step 2 - Logic Ground Open
• Turn the ignition OFF.
• Disconnect the power liftgate drive unit harness connector.
• Disconnect the power liftgate module C2 harness connector.
• Measure the resistance of both of the logic Ground circuits between the power liftgate drive unit harness connector and the power liftgate module C2 harness connector.
Is the resistance less than 2.0 ohms?
Yes
• Go to Test Step 3
No
• Repair the logic ground circuit for an open.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior
Test Step 3 - Position Sensor Signal 2 Circuit Short to Ground
• Disconnect the power liftgate module C1 harness connector.
• Measure the resistance between ground and the position sensor signal 2 circuit.
Is the resistance less than 10k ohms?
Yes
• Repair the position sensor signal 2 circuit for a short to ground.
No
• Go to Test Step 4
Test Step 4 - Position Sensor Signal 2 Circuit Short to Voltage
• Turn the ignition ON.
• Measure the voltage between ground and the position sensor signal 2 circuit.
Is there any voltage present?
Yes
• Repair the position sensor signal 2 circuit for a short to voltage.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior
No
• Go to Test Step 5
Test Step 5 - Position Sensor Signal 2 Circuit Open
• Turn the ignition OFF.
• Measure the resistance of the position sensor signal 2 circuit between the PLG C1 connector and the drive unit connector.
Is the resistance less than 5.0 ohms?
No
• Repair the position sensor signal 2 circuit for an open.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior
Yes
• Go to Test Step 6
Test Step 6 - Position Sensor Supply Circuit Open
• Measure the resistance of the position sensor supply circuit between the power liftgate module C1 harness connector and the power liftgate drive unit harness connector.
Is the resistance less than 5.0 ohms?
Yes
• Go to Test Step 7
No
• Repair the position sensor supply circuit for an open.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior
Test Step 7 - Position Sensor Supply Circuit Short to Ground
• Measure the resistance between ground and the position sensor supply circuit.
Is the resistance less than 10k ohms?
Yes
• Repair the position sensor supply circuit for a short to ground.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior
No
• Go to Test Step 8
Test Step 8 - Position Sensor Signal 2 Circuit Short to Position Sensor Signal 1 Circuit
• Measure the resistance between the position sensor signal 2 circuit and the position sensor signal 1 circuit.
Is the resistance less than 10k ohms?
Yes
• Repair the position sensor signal 2 circuit for a short to the position sensor signal 1 circuit.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior
No
• Go to Test Step 9
Test Step 9 - Power Liftgate Module
• Reconnect the power liftgate module C1 harness connector.
• Reconnect the power liftgate module C2 harness connector.
• Reconnect the power liftgate drive unit harness connector.
• Turn the ignition ON.
• While back probing, measure the voltage between ground and the position sensor supply circuit in the power liftgate drive unit harness connector.
Is the voltage approximately 4.8 volts?
Yes
• Go to Test Step 10
No
• Replace the power liftgate module.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior
Test Step 10 - Power Liftgate Drive Unit
• Be sure the liftgate is in the full open position.
• While back probing, measure the voltage between ground and the position sensor signal 2 circuit in the power liftgate drive unit harness connector.
• While observing the voltmeter, manually lower the liftgate in short steps, waiting about one second between steps. Do this for about 12 steps.
Does the voltage toggle from approximately 4.8 volts to approximately 0.02 volts?
Yes
• Replace the power liftgate module.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior
No
• Replace the power liftgate drive unit.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior