Symptom Chart - 4WD
WARNING: This page is about a different car, the 2017 Lincoln Navigator and 2017 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.
Symptom Chart - Four-Wheel Drive (4WD)
| Condition | Possible Sources | Action |
|---|---|---|
| No communication with the TCCM | Scan tool DLC TCCM Circuitry |
REFER to Module Communications Network . |
| The 4X4 mode indicators do not operate correctly/do not operate | IPC 4WD system fault HS-CAN TCCM Ignition switch and/or circuitry |
GO to Pinpoint Test V . |
| The vehicle does not shift between 2H (2WD) and 4X4 modes correctly | MSS Transfer case Transfer case clutch IWE TCCM Circuitry |
GO to Pinpoint Test X . |
| The vehicle does not shift between 4A (4X4 AUTO) and 4H (4X4) modes correctly | MSS Transfer case Circuitry TCCM |
GO to Pinpoint Test O . |
| Vehicle has no torque or inadequate torque at front wheels in 4A (4X4 AUTO) mode | Transfer case Circuitry TCCM |
CARRY OUT the 4WD System Functional Test. GO to Pinpoint Test U . |
| The vehicle does not shift between 4H (4X4) and 4L (4X4 LOW) modes correctly | Transfer case MSS TCCM Transmission drag torque |
GO to Pinpoint Test P . |
| 4WD does not engage at speed correctly | Transfer case clutch coil TCCM IWEs |
GO to Pinpoint Test Q . |
| The front axle does not engage/disengage correctly | MSS IWEs IWE solenoid Vacuum leaks TCCM Front halfshaft Vacuum check valve(s) |
GO to Pinpoint Test N . |
| The 4WD system jumps out of gear | Transfer case IWE vent MSS |
GO to Pinpoint Test R . |
| Unable to duplicate customer concern | 4WD system and/or related components | CARRY OUT the 4WD System Functional Test. GO to Pinpoint Test U . |
| Unable to achieve flat tow (neutral tow) mode | Wiring, terminals or connectors HS-CAN IPC TCCM Door ajar switch Ignition switch |
GO to Pinpoint Test Y |