Pinpoint Test F : The 4WD System Jumps Out Of Gear
WARNING: This page is about a different car, the 2016 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.
- F1 CHECK FOR OBSTRUCTED IWE VENT LINES
- With the vehicle in NEUTRAL, position in on a hoist. Refer to Jacking and Lifting .
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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. No GO to F2. - F2 CHECK THE MSS SWITCH POSITION (4X4_SW) PID
- Ignition ON.
- Switch the MSS, to 4x2 (2H) mode.
- Enter the following diagnostic mode on the scan tool: TCCM DataLogger.
- Drive the vehicle.
- Dynamically monitor the 4X4_SW PID while driving the vehicle in each MSS position.
MSS Position PID Status 4X2 2WD 4X4 AUTO Automatic 4X4 4WD-HIGH
Does the PID always agree with the MSS position?
Yes GO to F3. No GO to Pinpoint Test D . - F3 CHECK THE 4WD INDICATORS
- Apply the brakes and stop the vehicle.
- Observe the 4WD indicators in the IPC while cycling through each MSS position.
Do the 4WD indicators match MSS switch positions?
Yes GO to Pinpoint Test D . No GO to F4. - F4 CHECK FOR TCCM DTCs
- Shift the transmission into the PARK position.
- Ignition ON.
- Switch the MSS, to 4x2 (2H) mode.
- Enter the following diagnostic mode on the scan tool: TCCM Self-Test.
Are DTC s present?
Yes REFER to the TCCM DTC Chart . 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 .