P279E: Four Wheel Drive (4WD) Range Signal Circuit Range/Performance

P279E flags a 4WD range signal that is electrically present but does not make sense: it may show a range the transfer case cannot be in, jump between high, low and neutral without a request, or contradict what the speed ratio across the transfer case shows. Such a plausibility check typically compares the reported range with commanded shifts and with the measured ratio monitored by P279A to P279C. No manufacturer documents P279E publicly with set conditions; GM's 2008 Two-Mode Hybrid control module shows how the same range information is validated by its circuit code P279D, and CARB 13 CCR 1968.2 requires rationality checks for such inputs. Causes are a misadjusted or worn range sensor, a shift motor stopping between positions, or wiring that intermittently loses contact.

Medium severity. Can I keep driving?Drive gently to a repair shop. If it slips, you hear clunks, or it loses its gears, do not keep driving.

Symptoms

4WD indicator shows a range that does not match the actual drive
Range shifts refused or completed only partly
Warning lamp

Most likely causes

Worn or misadjusted transfer case range sensor
Transfer case shift motor stopping between ranges
Intermittent contact in the range signal wiring

What to check, in order

Start with the simplest. You can tick off each step.

Check the fluid level and condition
Compare the reading with other engine data while varying the engine speed.
Read the input and output speed in live data
Check the connector and wiring
Check for other related engine codes
Consult the manufacturer's procedure for the transmission

Good to know

Repair difficulty: medium
It affects emissions.

What each character of P279E means

P: Powertrain: engine and transmission
2: Generic code: same on every make
7: Transmission
9E: Specific fault in that system

Frequently asked questions

Can I keep driving with code P279E?

Drive gently to a repair shop. If it slips, you hear clunks, or it loses its gears, do not keep driving.

What causes code P279E?

The most common causes are: worn or misadjusted transfer case range sensor; transfer case shift motor stopping between ranges; intermittent contact in the range signal wiring.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.