Checks, in order
- Indicator lightsWatch the 4WD lights when you move the switch. A flashing light means the system did not complete the shift and may have a stored code.easy $ · under about $50
- Fuses and wiringCheck the fuses and the actuator connectors for corrosion. Water in a connector can stop the shift.easy $ · under about $50
- Front axle actuatorInspect for a stuck shaft or a failed actuator. Cleaning and lubing may free it, otherwise replace it.medium $$ · about $50 to $500
- Transfer case actuator and fluidCheck the fluid level and condition, and listen for the motor when you change modes. A dead motor needs replacing.medium $$ · about $50 to $500
- Test on loose groundBinding on dry pavement is normal for part time systems. Test on gravel or dirt before assuming a fault.easy $ · under about $50
Applies to: 2003 to 2009 4Runner with the 4.0L 1GR-FE V6 and the 4.7L 2UZ-FE V8, 2WD and 4WD. Engine specific items are labeled, and some issues apply mainly to early model years.
Tools and parts for these checks
Links below are Amazon affiliate links: as an Amazon Associate, toyotadata earns from qualifying purchases, at no extra cost to you. Confirm fitment for your exact truck before you order.
| ITEM | USED FOR | BUY |
|---|---|---|
| Gear oil for your truck | Changing front diff and transfer case oil to the factory spec | Shop on Amazon |
| Fluid transfer pump | Filling through the fill or check plug | Shop on Amazon |
| Digital multimeter | Voltage, ground and continuity checks | Shop on Amazon |
| 1/2" drive click torque wrench | Tightening suspension and driveline bolts to spec | Shop on Amazon |
The same problem on other Toyotas
- 2nd Gen Tacoma (2005–2015): 4WD won't engage, 4WD light flashing, or grinding in four-wheel drive
- 1st Gen Tacoma (1995.5–2004): 4WD won't engage or front axle doesn't seem to drive
- 3rd Gen 4Runner (1996–2002): 4WD won't engage or front axle seems stuck
- FJ Cruiser (2007–2014): 4WD will not engage, or the A-TRAC / VSC lights come on
Other drivetrain problems on the 4th Gen 4Runner
More 4th Gen 4Runner problems
- V6 losing coolant, cold start misfire or overheating (early 4.0L) (Engine)
- Frame rust or rusted suspension mounts (Frame & Body)
- Clunk, knock or wandering from the front suspension (Steering & Suspension)
- Sticky, melting or cracked dashboard (Body & Electrical)
- V8 timing belt service: when is it due? (Engine)
- Ticking or diesel-like noise on cold start (Engine)
All 16 4th Gen 4Runner symptoms in the interactive troubleshooter →
General guidance from owner experience. Confirm torque specs, fluid capacities and procedures in the factory service manual. Brakes, steering and anything structural: if in doubt, have a qualified shop inspect it before driving.