Diagnostic Test

DIAGNOSTIC TROUBLE CODE (DTC) PRESENT
NOTE: If there are any other Power Liftgate DTCs present, repair them before proceeding with this test.

NOTE: Make sure the battery is fully charged and serviceable before proceeding.
1. Make sure the liftgate is closed and with the scan tool, run the "Latch Home Position Test" before proceeding to ensure the latch is positioned correctly.
2. Using the scan tool, record and erase DTCs.
3. Turn the ignition off, wait 10 seconds, then turn the ignition on.
4. Operate the power liftgate several times if possible.
5. Using the scan tool, read ACTIVE DIAGNOSTIC TROUBLE CODE (DTC)s.
  Does the scan tool display B1956-POWER LIFTGATE LATCH RELEASE - EXCESSIVE TIME?
  
  Yes
  - Go to step 2
  No
  - Using the SYSTEM WIRING DIAGRAMS as a guide, inspect the wiring and connectors for an intermittent condition. Operate the liftgate several times and check for any binding or other obstructions.
  - Perform the BODY VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
BINDING LIFTGATE
1. Examine the liftgate for proper alignment, worn or binding hinges, weak liftgate prop assembly, loose/hard weatherstrip, and track assembly for wear or anything that would cause an obstruction to proper operation.
2. If necessary manually operate the power liftgate on a known good vehicle and notice the effort needed to open and close for comparison.
3. Especially notice the effort needed to unlatch and close the liftgate.
  Were there any mechanical problems found?
  
  Yes
  - Refer to Service Information for the related symptom(s).
  - Perform the BODY VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
  No
  - Go to step 3
CHECK THE (Q84) LIFTGATE LATCH CINCH DRIVER CIRCUIT FOR AN OPEN OR HIGH RESISTANCE

Fig 1: Checking Liftgate Latch Cinch Driver Circuit For An Open Or High Resistance
Courtesy of CHRYSLER LLC
1. Turn the ignition off.
2. Disconnect the Power Liftgate Module C2 and C3 harness connectors.
3. Check the connectors for damage, corrosion, or pushed out pins. Repair any problems as necessary.
4. Reconnect the Power Liftgate Module C3 harness connector.
5. Disconnect the Power Liftgate Latch harness connector.
6. Measure the resistance of the (Q84) Liftgate Latch Cinch Driver circuit between the Power Liftgate Module C2 harness connector and the Power Liftgate Latch harness connector.
7. Wiggle the harness and check for an intermittent open condition.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go to step 4
  No
  - Repair the (Q84) Liftgate Latch Cinch Driver circuit for high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
CHECK THE (Q85) LIFTGATE LATCH RELEASE DRIVER CIRCUIT FOR AN OPEN OR HIGH RESISTANCE

Fig 2: Checking Liftgate Latch Release Driver Circuit For An Open Or High Resistance
Courtesy of CHRYSLER LLC
1. Measure the resistance of the (Q85) Liftgate Latch Release Driver circuit between the Power Liftgate Module C2 harness connector and the Power Liftgate Latch harness connector.
2. Wiggle the harness and check for an intermittent open condition.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go to step 5
  No
  - Repair the (Q85) Liftgate Latch Release Driver circuit for an open or high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
CHECK THE (Q901) LOGIC GROUND WIRE FOR AN OPEN OR HIGH RESISTANCE

Fig 3: Checking Logic Ground Circuit For An Open Or High Resistance
Courtesy of CHRYSLER LLC
1. Measure the resistance of the (Q901) Logic Ground circuit between the Power Liftgate Module C2 harness connector and the Power Liftgate Latch harness connector.
2. Wiggle the harness and check for an intermittent short condition.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Go to step 6
  No
  - Repair the (Q901) Logic Ground circuit for an open or high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
CHECK THE (G78) LIFTGATE AJAR SWITCH SENSE CIRCUIT FOR AN OPEN OR HIGH RESISTANCE

Fig 4: Checking Liftgate Ajar Switch Sense Circuit For An Open Or High Resistance
Courtesy of CHRYSLER LLC
1. Measure the resistance of the (G78) Liftgate Ajar Switch Sense circuit between the Power Liftgate Latch C2 harness connector and the Power Liftgate Latch harness connector.
2. Wiggle the harness and check for an intermittent open condition.
  Is the resistance below 5.0 Ohms?
  
  Yes
  - Replace the Power Liftgate Latch in accordance with the Service Information.
  - Perform the BODY VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
  No
  - Repair the (G78) Liftgate Ajar Switch Sense circuit for an open or high resistance.
  - Perform the BODY VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .