OBD-II code · Powertrain (generic, extended)
P279A Transfer Case Gear High Incorrect Ratio
When the transfer case is in High range the measured input/output speed ratio does not match the expected value. Worn chain or planetary set.
Is it safe to drive with P279A?
Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.
Common causes
- Most likelyStretched transfer case chain
- PossibleWorn planetary gear set
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 3–8 h
- Emissions test
- Usually unaffected
- Parts involved
- Transfer Case, Planetary Gear Set
Related codes
- P2797Electric/Auxiliary Transmission Fluid Pump A Performance/Stuck Off
- P2798Electric/Auxiliary Transmission Fluid Pump A Control Circuit Low
- P2799Electric/Auxiliary Transmission Fluid Pump A Control Circuit High
- P279BTransfer Case Gear Low Incorrect Ratio
- P279CTransfer Case Gear Neutral Incorrect Ratio
- P279DFour Wheel Drive (4WD) Range Signal Circuit
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.