Pinpoint Test AG: All-Wheel Drive (AWD) System Jumps Out of Gear
Four Wheel Drive (4WD) Systems - 1-Speed Torque-On-Demand
Pinpoint Tests
Pinpoint Test AG: All-Wheel Drive (AWD) System Jumps Out of Gear
Normal Operation
Once the All-Wheel Drive (AWD) system engages the user selected mode, that mode should be maintained. If the AWD system does not stay in the selected position, systematically check the AWD system components.
This pinpoint test is intended to diagnose the following:
- Integrated Wheel End (IWE) vent line(s)
- Mode Select Switch (MSS)
- Transfer case
PINPOINT TEST AG: THE 4WD SYSTEM JUMPS OUT OF GEAR
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AG1 CHECK FOR OBSTRUCTED IWE VENT LINES
- With the vehicle in NEUTRAL, position in on a hoist. Refer to Jacking and Lifting Service and Repair.
- NOTE: The IWE vent port is the smaller of the 2 vacuum ports.
- Disconnect the LH IWE line from the vent port.
- Attach a hand vacuum pump to the IWE vent line.
- Attempt to draw and hold a vacuum.
- Connect LH IWE line.
- Disconnect the RH IWE line from the vent port.
- Attempt to draw and hold a vacuum.
- Can a vacuum be held on either IWE vent line?
Yes
INSTALL new IWE vent lines as necessary. TEST the system for normal operation.
No
GO to AG2.
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AG2 CHECK THE MSS POSITION PIDs
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger - TCCM.
- Drive the vehicle.
- Dynamically monitor the 4X4_SW PID while driving the vehicle in each MSS position.
- Does the 4X4_SW PID always agree with the MSS position?
Yes
GO to AG3.
No
GO to Pinpoint Test AE. Pinpoint Test AE: The Vehicle Does Not Shift Between AWD (4X4 AUTO) and 4H (4X4) Modes Correctly
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AG3 CHECK THE 4WD INDICATORS
- Apply the brakes and stop the vehicle.
- Shift the transmission into the NEUTRAL position.
- Observe the 4WD indicators in the Instrument Panel Cluster (IPC) while cycling through each MSS position.
- Do the 4WD indicators match MSS switch positions?
Yes
GO to Pinpoint Test AE. Pinpoint Test AE: The Vehicle Does Not Shift Between AWD (4X4 AUTO) and 4H (4X4) Modes Correctly
No
GO to AG4.
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AG4 CHECK FOR DTCs
- Shift the transmission into the PARK position.
- Enter the following diagnostic mode on the scan tool: Self Test - TCCM.
- Are DTCs present?
Yes
REFER to the Transfer Case Control Module (TCCM) DTC Chart for diagnosis. Four Wheel Drive (4WD) Systems - 1-Speed Torque-On-Demand
No
CHECK the transfer case fluid level. REFER to Transfer Case Procedures. If the fluid level is OK, CHECK for internal transfer case faults. TEST the system for normal operation.
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