The P279B: Transfer Case Gear Low Incorrect Ratio refers to an issue where the ratio in the transfer case gear in low mode is incorrect. This could be due to a faulty transfer case gear, incorrect sensor readings, or control module malfunctions. It affects the vehicle’s ability to properly engage the low gear, which can impact driving performance, particularly in off-road or towing scenarios.
P279B – Quick Overview
| Code | Information |
|---|---|
| Meaning | P279B: Transfer Case Gear Low Incorrect Ratio |
| Is it serious? | Yes, this issue can impair the vehicle’s ability to switch gears effectively, especially in low gear, and may lead to potential drivetrain damage if not resolved. |
| Possible causes | – Incorrect ratio in transfer case gear low – Faulty transfer case gear or sensors – Control module issues |
| How to diagnose? | – Check the transfer case gear low ratio – Inspect transfer case gear and sensors – Verify control module functionality – Replace faulty gears or components as needed |
P279B Meaning
The P279B: Transfer Case Gear Low Incorrect Ratio code indicates that the gear ratio in the transfer case’s low mode is not within the expected range. This usually points to problems in the transfer case itself, the sensors monitoring it, or an issue in the control module that manages the gear ratios. A misalignment here can lead to difficulty in properly engaging the low gear, which is critical for situations requiring higher torque, such as towing or off-road driving.
Step-by-step diagnostic guide
| Action | Description | Tools Needed |
|---|---|---|
| Check for Other Codes | Use an OBD-II scanner to check if there are other related codes. Additional codes may help identify associated issues. | OBD-II Scanner |
| Inspect Transfer Case Gear | Visually inspect the transfer case for any signs of damage, wear, or misalignment in the low gear. | Flashlight, Safety Gloves |
| Check Gear Ratio | Use a diagnostic tool to measure the gear ratio in the transfer case low mode, comparing it to manufacturer specifications. | Diagnostic Tool, Service Manual |
| Inspect Sensors | Test the sensors connected to the transfer case to ensure they are functioning correctly and providing accurate readings. | Multimeter, Diagnostic Tool |
| Verify Control Module | Check the transfer case control module for proper operation, including software and electrical connections. | Multimeter, OBD-II Scanner |
| Replace Faulty Components | Replace any faulty gears, sensors, or control module components identified during testing. | Wrench Set, Replacement Parts |
| Clear the Code and Test Drive | After making repairs, clear the code using an OBD-II scanner and take the vehicle for a test drive to confirm the issue is resolved. | OBD-II Scanner, Vehicle Owner’s Manual |
| Recheck for Codes | After the test drive, re-scan the vehicle to ensure the P279B code has not reappeared. If the code returns, further diagnosis may be needed. | OBD-II Scanner |
Free PDF: How to choose OBD2 scanner
I’ve made you a free PDF to choose the OBD2 scanner in 5 minutes.
✅ Which OBD2 scanner is best?
✅ Which type should you get (DIY, Pro, Hobby)
✅ What is the best scanner for the exact brand/feature (e.g best for BMW)
✅ How to get a Bi-Directional tool for as cheap as $40
✅ Discount coupons for scanners
PDF is 100% free and it is designed to help you pick a scanner in less than a few minutes! Not a boring 50-page guide.
Just tell me where to send it.
