# hesitation at 140km/h



## k87n (10 mo ago)

i don't know if you guys have a strange loss of power at around 140 km/h look like a transmission issue. She downshift and don't know what to do..


----------



## rogoman (Dec 16, 2004)

State your model, year, engine, transmission so that we know what specs to look up!

One of the first things to do is perform an ECU code readout with a portable scan tool to see if any fault codes are set. The tool can be purchased at most auto parts stores. Post the actual codes here on the forum so that we may be able to help you further. If there is one or more fault codes set, they can help point to the malfunction. If you have a copy of the FSM for your vehicle, the code readout procedure is described there along with a listing of codes. You can download a copy of the FSM from these web sites: Owner's Manuals or https://diyservicemanuals.com/. The section EC.PDF is the one you need to read.

Replace the spark plugs and air filter if they're old. Inspect your engine grounds, since it only takes a few seconds to do the test. With the car running, put a voltmeter on the lowest scale and measure from the block to the negative battery post. It should read no more than 50 millivolts (0.05V). Ground cable deterioration can cause blown coils and a host of other symptoms. If the ground is good, inspect the MAF for lint, butterfly wings, or any other kind of junk.


----------



## k87n (10 mo ago)

i will check everything you said. i have a fixd and no code came out. Its a Sentra 2018 qg18 with a cvt transmission (i don't know much about the transmission).


----------



## VStar650CL (Nov 12, 2020)

If it's an '18 it's an MRA8. The QG18 has been out of production since '08.


----------

