Shift Pointers: Nissan’s no throttle response - Transmission Digest

Shift Pointers: Nissan’s no throttle response

Nissan vehicles using continuously variable transmissions (CVTs) are notorious for defaulting to a no throttle response when the vehicle is engaged into gear. There are several malfunctions that can cause this protective failsafe feature to be initiated. A brake switch (stop lamp switch) stuck on, a double-footed driver, blown or incorrect brake bulbs, and wheel speed sensor malfunctions are among the potential causes.

Some owners have described this as a “no move” condition thinking it’s a failed transmission. And it can also be falsely blamed if tail light grounds are compromised, or the lens has filled with water.

Danny at Bass Transmissions ran into another reason for this to occur. The cause could have been elusive, but Danny homed in on it quickly. The vehicle in this case was a 2008 Nissan Altima 3.5L using the RE0F09B CVT whose throttle, while in Park or Neutral, was working. But once in gear, at 20% throttle or more there was no throttle response. Below 20% throttle, he could ease into the throttle, and it would drive fine with the power it provides at that low percentage of opening.

After discovering this on a road test, Danny brought the vehicle back to the shop. He popped the hood and had his assistant brake torque the engine above 20% throttle to see if anything strange would reveal itself—and it did. As the engine rotated under load, it opened a crack between the ribs of the accordion air duct hose as seen in Figure 1, above.

When the throttle opening was less than 20%, the accordion would not expand enough to open this crack, allowing the throttle to function normally (see Figure 2).

Figure 2.
Figure 2.

This leak coming in after the MAF sensor will negatively affect the air/fuel mixture, which the O2 sensor will pick up on. What can make this problem an elusive one to find is that a code was not set because of it, yet the computer chose to initiate the no throttle response in response to this unexpected air to fuel ratio.

The quality of the air/fuel mixture is essential for the efficiency of a three-way catalytic torque converter. With this malfunction, a throttle shut down would eliminate any possibility of an emission problem. Once Danny replaced the air duct assembly, throttle operation returned to normal.

I spoke to a good friend Jerry “G” Truglia to ask him why a P0420 or P0430 did not set, explaining that the throttle shut down. His response was that over time from a lean condition that is caused by pirated air, it can cause a P0420 or P0430. I have seen that many times. If the MAF is not measuring all the air, you would think that a P0101 MAF DTC code would set, but that is not always the case. Nissan has had problems with the MAF and has released a bulletin for reprogramming to fix the problem.

We perform a test that should be done on all vehicles with a MAF and rubber boot. The boot becomes dry and when motor mounts get weak or break, the boot displays a problem from over flexing. I always recommend brake loading in reverse and driving to make sure the MAF boot is not ripped. The O2—or in this case, an Air Fuel / Wide Range sensor—should read 1.4 volts at idle on a good running engine.

If the voltage is above 1.4 volts, the mixture is Lean—the opposite of an O2 sensor. If the voltage is under 1.4 volts, the sensor is seeing a Rich mixture. The vehicle uses a regular O2 for the rear sensor. Thanks for the added insight G!

You May Also Like

GM 6T70/75 slips and delays in first

A 2015 Chevrolet Equinox equipped with the 3.6-liter engine and 6T75 transmission has complaints of a delayed engagement into drive and slips in first gear.


The complaint

A 2015 Chevrolet Equinox equipped with the 3.6-liter engine and GM 6T75 transmission has complaints of a delayed engagement into drive and slips in first gear.

The cause

A generation one 1-2-3-4 Clutch Apply Piston was installed into a generation two transmission. The generation two 1-2-3-4 Clutch Apply Piston apply fingers are .147 in. taller than the generation one piston. This created too much clutch clearance for the clutch pack to effectively hold.

How to fix GM 6T70/Ford 6F50 rattling noise with transmission in gear

A rattling noise is coming from the transmission whenever the engine is running and the transmission is in gear.

The importance of the follow-up road test after transmission replacement

A 2002 Lexus RX300 equipped with a 3.0-liter V6 engine and U140F transmission was brought into our facility with a few concerns. The customer said that “it has a leak, a grinding noise when taking off from a stop, and it just doesn’t seem to shift right.” Related Articles – Sonnax introduces Sure Cure Kit

RR Tech Feature Oct
Tips and tricks for Chrysler switch valve plug testing

As technicians, we are often faced with build issues that can sometimes be frustrating at first. But with a little ingenuity, these frustrations can be turned around and made simple. Related Articles – ETE Reman: Ever expanding – Jatco/Nissan JF011E critical wear areas and vacuum test locations – ZF 6HP26: A torque calculation error In

GM 8L90 #7 Check-ball: The overheat that saved the day

Beginning in October of 2015, GM removed the #7 Check-ball from the solenoid valve control body in the 8L90 transmission (see Figure 1). This was done in conjunction with the elimination of the Lube Override Enable Valve from the upper valve body as shown in Figure 2. Related Articles – What 105 years of history

Other Posts

Are you down with CVT?

The continuously variable transmission has its critics, but it’s probably here to stay.

CVT generic
Watch: CVT modules and programming

CVTs usually will require a reset to the basic factory programming after repairing a major component. You can typically use a scan tool to help complete this. Watch the latest video from Transtar, above, for more. Related Articles – Road to AAPEX season 2 finale: Where the road ends and the show begins – Road

Watch: CVT fluid diagnostics

CVT fluids are different than automatic transmission fluids. Learn why the requirements for these fluids are different and how to select the right fluid for your vehicle. Watch the latest video from Transtar, above, for the answer. Related Articles – Watch: CVT electric and communication codes – Road to AAPEX Ep. 8: Paving the way

Watch: CVT electric and communication codes

Find out if your transmission module is not sharing information properly. Different codes will indicate different issues within the transmission. Watch the latest video from Transtar for more information. Related Articles – Road to AAPEX Ep. 6: Historic mile markers on the road of progress – Road to AAPEX Ep. 5: At the crossroad of