Pinpoint Test L : P1839:00, P1840:00 And P1841:00: Notes
WARNING: This page is about a different car, the 2020 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.
Refer to Two Wheel Drive/Four Wheel Drive Systems for schematic and connector information
Normal Operation
The high-low shift occurs when the reduction shift fork moves the high-low collar to lock the planetary gear set to the output shaft. The torque transmitted through the sun gear from the input shaft turns the front planetary gear set assembly. The front planetary gear set assembly, now engaged, provides transfer case speed reduction. Certain criteria, such as vehicle speed and TR selection must be met before this shift can occur. Systematically check the necessary inputs and outputs of the TCCM, components of the transfer case, IWE components and halfshafts.
DTC Fault Trigger Conditions
| DTC | Description | Fault Trigger Conditions |
|---|---|---|
| P1839:00 | Transfer Case Shift Motor Open Circuit: No Sub Type Information | This DTC sets when the TCCM detects battery voltage less than 9 volts for 5 seconds or more at TCCM. |
| P1840:00 | Transfer Case Shift Motor Short Circuit To Battery: No Sub Type Information | This DTC sets when TCCM detects a short to voltage. Shift motor moves are prevented when this DTC is set. |
| P1841:00 | Transfer Case Shift Motor Short Circuit To Ground: No Sub Type Information | This DTC sets when TCCM detects a short to ground. Shift motor moves are prevented when this DTC is set. |
Possible Sources
- Wiring, terminals or connectors
- TR
- ABS wheel speed inputs
- Transfer case
- TCCM
- Transmission drag torque