Transfer Case Control System (MIL Request)
The transfer case control module has requested the ECM/PCM to illuminate the MIL because of a fault on its side that is emissions- or driveline-relevant. The original fault is in the transfer case module itself.
Affected components
- Transfer case module
Common causes
- High likelihood: Internal fault in transfer case module — read its DTCs
Possible symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
Diagnostic notes
- The malfunction indicator lamp may illuminate
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.