OBD-II code · Powertrain (generic)
P0800 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.
Is it safe to drive with P0800?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyInternal fault in transfer case module — read its DTCs
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
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.5–4 h
- Emissions test
- Usually unaffected
- Parts involved
- Transfer Case Module
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.