Pinpoint Test R: The Four-Wheel Drive (4WD) System Jumps Out of Gear
Four Wheel Drive (4WD) Systems - 2-Speed Torque-On-Demand
Pinpoint Tests
Pinpoint Test R: The Four-Wheel Drive (4WD) System Jumps Out of Gear
Normal Operation
When the Four-Wheel Drive (4WD) system engages the user selected mode, that mode should be maintained. If the 4WD system does not stay in the selected mode, systematically check the 4WD 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 R: THE 4WD SYSTEM JUMPS OUT OF GEAR
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R1 CHECK FOR OBSTRUCTED IWE VENT LINES
- With the vehicle in NEUTRAL, position it on a hoist. Refer to Vehicle Jacking and Lifting.
- 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 the 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 R2.
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R2 VERIFY THE CONCERN
- Drive the vehicle and attempt to duplicate the concern.
- Is the concern an uncommanded range shift (in or out of 4L mode)?
Yes
GO to R5.
No
GO to R3.
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R3 CHECK THE 4WD SWITCH STATUS (4WDINP_SW) PID
- Connect the scan tool.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger - TCCM.
- Drive the vehicle.
- Monitor the 4WDINP_SW PID while driving the vehicle in each MSS position.
- Does the 4WDINP_SW PID always agree with the MSS position?
Yes
GO to R4.
No
GO to Pinpoint Test N. Pinpoint Test N: The Front Axle Does Not Engage/Disengage Correctly
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R4 CHECK FOR DTCs
- 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. Four Wheel Drive (4WD) Systems - 2-Speed Torque-On-Demand
No
GO to Pinpoint Test U. Pinpoint Test U: Four-Wheel Drive (4WD) System Functional Test
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R5 CHECK THE 4WD INDICATORS
- Stop the vehicle.
- Shift the transmission into the NEUTRAL position.
- NOTE: 2H is indicated by the absence of 4X4 AUTO, 4H or 4L mode indicators in the Instrument Cluster (IC) message center.
- Observe the 4WD indicators in the IC while cycling through each MSS position.
- Do the 4WD indicators match MSS switch positions?
Yes
GO to R3.
No
GO to R6.
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R6 CHECK FOR DTCs
- Enter the following diagnostic mode on the scan tool: Self Test - TCCM.
- Shift the transmission into the PARK position.
- Carry out the on-demand self-test.
- Are DTCs present?
Yes
REFER to the Transfer Case Control Module (TCCM) DTC Chart. Four Wheel Drive (4WD) Systems - 2-Speed Torque-On-Demand
No
CHECK the transfer case fluid level. REFER to Transfer Case. If the fluid level is OK, CHECK for internal transfer case faults. REFER to Transfer Case. TEST the system for normal operation.
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