All Wheel Drive Clutch Temp High Error

Let me go on a short rant. I have talked to several R35 GT-R owners about the same warning: AWD Clutch Temp High. The warning appears, the owner panics and the first thing I hear is, “I did not do anything.”

Well, except for changing the wheels and tires.

The new setup may look great, but if the front and rear tires have significantly different rolling diameters, the GT-R sees the axles turning at different speeds. The ATTESA system may interpret that speed difference as slip and work the front drive clutch more than it should. That creates heat. Continued operation can damage the clutch pack and other expensive driveline components.

If the warning appears while driving, slow down, pull over somewhere safe and let the car idle. The factory owner’s manual says the car may change to rear wheel drive to protect the AWD system. If the warning does not clear, or it returns after tire size, pressure and wear are corrected, the car needs proper diagnosis. I would not keep driving it hard and hope the problem goes away.

Start With What Changed

Basic troubleshooting still works:

1. Identify the warning and any stored fault codes.
2. Ask whether the problem existed before the wheels or tires were changed.
3. Verify all four tire sizes, actual measured diameters, inflation pressures and tread depths.
4. Put the original known good setup back on the car.
5. Confirm whether the warning is gone.

Do not assume the printed tire size tells the whole story. Two tires marked with the same nominal size can have different published diameters and revolutions per mile. Brand, model, wheel width, pressure, load and tread wear all matter.

Why Tire Diameter Matters on an R35 GT-R

The R35 GT-R uses a rear mounted GR6 dual clutch transaxle and Nissan’s ATTESA all wheel drive system. A second driveshaft sends drive forward from the rear transaxle to the front differential.

A hydraulically controlled multiplate clutch regulates how much torque is sent to the front wheels. The car normally behaves as a strongly rear biased AWD vehicle, then adds front torque when the control system determines that it is needed. Nissan describes an operating range from 0:100 front to rear to as much as 50:50.

The front and rear wheels do not need to be exactly the same width or use the same sidewall aspect ratio. They do need to produce closely matched rolling circumferences. If one axle is consistently rotating faster than the other during straight line driving, the AWD clutch can be forced to absorb that difference as slip. Slip becomes heat.

How Close Should the Front and Rear Tires Be?

Overall tire diameter is the number that matters. A tire being a 255, 285 or 315 does not by itself tell you whether the combination will work. Neither does the wheel being 18, 19 or 20 inches.

Use the tire manufacturer’s specification for overall diameter and revolutions per mile whenever possible. Then measure the tires on the car, especially when mixing models or using tires with different amounts of wear.

My practical R35 guideline has been:

• 0 to 4 mm difference: Good target
• 4 to 8 mm difference: Usually workable, but verify the actual tire specifications
• 8 to 12 mm difference: Questionable
• More than 12 mm difference: High risk of a warning or unwanted AWD clutch activity

This is a field guideline, not a published Nissan tolerance. Nissan’s instruction is more direct: use the specified tires on all four wheels and check tire size, pressure and wear when the AWD light flashes slowly. The closer the rolling diameters are, the happier the system will be.

You can estimate an unloaded tire diameter with this formula:

Diameter in millimeters = wheel diameter × 25.4 + 2 × section width × aspect ratio ÷ 100

That calculation is only a starting point. Published measured diameter and revolutions per mile are better because real tires do not always match the nominal math.

Original 2009 to 2012 R35 GT-R Wheel and Tire Sizes

Position	Wheel	Offset	Tire	Approximate diameter
Front	20 × 9.5	+45	255/40R20	About 28.0 inches
Rear	20 × 10.5	+25	285/35R20	About 27.9 inches

The factory combination is staggered in width but closely matched in diameter. Many other combinations can work, including square setups and wider staggered setups, but every combination must be checked using the specifications for the exact tires being installed.

R35 Warning Checklist

If you see AWD Clutch Temp High or a front/rear tire size discrepancy warning, check the following:

• Exact tire size on every corner
• Manufacturer and tire model on every corner
• Published overall diameter and revolutions per mile
• Cold tire pressure
• Tread depth and uneven wear
• Whether one or two tires were recently replaced
• Wheel speed sensor or ABS faults
• AWD, transmission and related stored diagnostic codes
• Transfer clutch fluid temperature and system operation if the tire setup checks out

Do not keep clearing the warning without finding the cause. A mismatched tire setup is common, but it is not the only possible fault.

ATTESA in the R32, R33 and R34 Skyline GT-R

The R32, R33 and R34 Skyline GT-R also use Nissan’s rear biased ATTESA E-TS system, but the hardware layout is different from the R35. The Skyline has a conventional front mounted engine and transmission. A hydraulic multiplate clutch in the transfer case varies drive to the front axle while the rear wheels remain mechanically driven.

• R32 GT-R: ATTESA E-TS controls the front to rear torque split through the transfer clutch.
• R33 GT-R: Standard models use ATTESA E-TS. V·Spec models use ATTESA E-TS Pro, which adds an electronically controlled active rear limited slip differential.
• R34 GT-R: Base models use ATTESA E-TS. V·Spec, V·Spec II, M·Spec and Nür based models use E-TS Pro with the active rear differential.

E-TS Pro does not mean the rear differential independently sends torque left or right like a modern torque vectoring differential. It changes rear differential lockup while the transfer clutch controls how much drive is sent toward the front axle.

The same basic lesson applies to the Skyline GT-Rs: tire diameter, tire wear, wheel speed signals and proper hydraulic operation matter. I have burned up ATTESA transfer cases in R33 GT-Rs after ignoring tire mismatch advice. I was wrong. Learn from my expensive mistake and do the math before installing whatever wheel and tire package happens to be fashionable this month.

For a deeper explanation, diagnostic information and diagrams, read the complete ATTESA E-TS and E-TS Pro technical guide or browse all GTRUSABlog ATTESA articles.

Shopping for a Skyline GT-R?

ATTESA condition should be part of any R32, R33 or R34 GT-R inspection. Look for warning lights and fault codes, confirm that the pump operates correctly, inspect the fluid level and leaks, check tire matching and verify that the transfer system is not binding.

Toprank Importers sources, imports, inspects and sells legal Japanese vehicles, including the R32 GT-R, R33 GT-R and R34 GT-R. You can also browse the complete Japanese vehicle inventory at Importavehicle.com.

Bottom line: If an AWD warning appears after a wheel or tire change, stop blaming the car and check the rolling diameter first. A few minutes with the tire specifications and a tape measure can save a very expensive transfer clutch or transmission repair.

Reference: 2009 Nissan GT-R Owner’s Manual. Always follow the instructions for your specific model year.