Anyone seen this code? U1024,VVEL CAN communication
 

So I just installed the gtm stage IITT kit and Iam getting this code,( U1024,VVEL CAN communication). Has anyone seen or heard of this? I tried clearing the code per sam's request but it wont clear. I have already checked all vacuum lines, and cupplers for leaks...Any ideas?

Did you reconnect the connector on the fuel rail underneath the plenum when you installed the injectors? It sounds like you just forgot to plug something back in.

This... or a blown sensor.

I managed to clear that code and went for a short ride while data logging... Just got towed home. The car went completely dead and I was stranded. It wouldn't even jump off.. Oh well back to the drawing board....

CAN is how the different modules in the car talk to each other - similar to TCP/IP and the Internet. Sounds like you have a bad connection in the VVEL system (or a bad communications module in one of the devices). The FSM (see link in sig) will be a big help tracking down the wiring and connectors.

Decided to look over the battery again and turns out the 140A fuse that sits on the very top is blown. At this point Iam guessing that the positive starter cable has grounded somewhere down there causing the fuse to blow... Trial and error right... ha

I would never drive a car again if I do not know what the code means. Even clearing will only be temporary fix. Sometimes one code has several issues it could be. I had my share and have learned the hard way, which you have as well. Good luck.

Thanks for the advice but sam had told me to try to clear the code then try again.. No room for error right...

Are we talking about Sam@GTM? Who did the install? Self? A shop? Hopefully, you get your Z back on the road soon.

There are not many codes that can be ignored with regard to the Z's finicky systems. Unfortunately, I have one of those codes right now P1421 - Cold Start Control. Fix action - reprogram ECM.

Yes sam from gtm, and I did the install. Mine also had the cold start issue alont with that oher fod mentioned. I finally had to put the stock file back in and then the gtm tt again. I also found that the driver side turbo was not clocked in the right position causing a few other fitment issues and now I also think thats were the issue lies since it is so close to the starter connector a the bottom turbo fitting....

Word. I hope you get it all sorted

That P1421 will not go away. You can go back to stock and then re-flash, but it WILL come back. You will either have to convince GTM to turn off that DTC or just live with it. I will be going back down to UPREV in a week or so. I will be asking about that one for myself, so I will share the results.

I just got this code (P1421) today pulling out of the garage. Haven't driven the car all winter and still didn't drive it today. I wiped it and will see if it comes back next time I go for a drive.

Any idea what causes it?

Not really sure of the cause. The fix action according to the FSM is reprogram ECM. I will be visiting UPREV sometime in the near future to see about a possible fix action though. I will report back at that time.

I cleaned the throttle bodies a while back and haven't driven the car since. I looked that it can also be caused by not getting enough air during a cold start. This could be caused because I didn't perform the throttle position/idle air relearn procedure.

Ok after looking over things it seems the positive wire coming from the alternator going to the battery rubbed against the exhaust manifold causing it to melt and blow that 140A fuse on top of the battery. I have already replaced that cable and made sure this time around that it was no where near the exhaust manifold. Finished up everything and started it up with No codes..... Cant thank you guys enough for such a great community on helping each other out.

Subd for rop's info.

Glad you found the problem. Now I just have to deliver on that P1421 issue fix action.

Sent from my D-Team-MT4GS-CM10.1

Glad you found the problem and got it fixed up. :hello:

Well hopefully that fixes the problem, today I will drive it again to see what happens. Before all of that the car would just die when you got on it hard but would allow you to restart it all without throwing a code. Cant say enough about gtm in regards customer service, Sam, Pablo, and mike have been excellent!!

Drove the car again today after going through everything again and it seemed to be fine with no engine light. Now the DTC light stays on and the light above it showing the other half of the traction control system light also stays on. Whats weird is when I turn the car off and start it again it goes away but comes on shortly after driving... Guess Iam going to have to live with it being on all of the time...

You don't have to live with it, it is a simple fix. This is happening because the steering angle sensor did not go back to its original position (miss-aligned steering coupler). So basically, what is happening is that every time you shut off the car, it resets itself and will not trigger the VDC light until the steering angle sensor indicates a problem and that is what is happening when you make a turn. So there are two solutions: relearn the steering angle position via CONSULT III or recheck/redo your installation on the steering coupler.

Sam

Just wanted to pop in and let you guys know that I have an appointment with UPREV next week for inspection/troubleshooting. For some reason, I only have the P1421 code on my low boost map and boost control setting. If I run my high boost tune and boost control setting, no P1421. Strange..........

Props to Sam for popping in and offering solutions to Cosmo's issue.

Sent from my SGH-T889 using Tapatalk 2

Going on vacay for a week so will check back when I get back...

I'm back but this time I got the U1024. Only happened when I flashed back to stock. I was putting the sl fuse back in the ipdm so I hope I didn't mess with anything. Car still seems to run fine though.

I finally had to take it to Nissan and they had to reset the steering angle to 0 and replace my clock spring but they did it under warranty.. I was sweating bullets while negotiating if they would do it under warranty. All fixed and good...

Error code U1024
 

COSMO

I was looking at an old thread you posted on error code U1024. I’m getting the same code and not sure what is causing it. Do you remember specifically what the issue was?

Here is a list of my add-on/mods:

1. UpRev
2. Berk High Flow Cats and Cat aBack Exhaust
3. Nismo Cold Air Intakes
4. Mishimoto Aluminum Radiator
5. Oil & Power Steering Coolers

Any help would be much appreciated. Thanks!

I don't think he will be responding. I believe he is currently serving a lifetime ban from the forum.

He hasn't posted in 2 years. When his motor blew the last time. That was it for him. He has moved on.

My Z is fixed and running better than ever. I replaced the VEL control Module, adjusted the VEL Actuator Sensors myself with UpRev software and didn't have to part with $3200 like the Nissan dealer said I needed to.

When I took my car to Nissan and supposedly spoke to their top mechanic, he had no clue what I was talking about until I showed him in the 370Z service manual. There is absolutely no excuse for that if you are the top shop mechanic.

Do yourself a favor and read the service manual; you'll know just as much as the Nissan Dealer Mechanics.

:ughdance:

What was the fix for the P1421 out of curiosity? My Z is getting it now after an UPREV tune and ART Pipes.

Uprev is the issue but its completly random some of the time when you flash an ecu with their software it will set one of the u codes for "insert module here" to ecu can failure. I have seen u1024 u1023 and others sometimes multiples. Some times a different map fixes it sometimes using an older or newer revision of your rom fixes it and sometimes you have to get one of the expensive boxes replaced. All I know is it only happens to reflashed ecu's specifically with uprev.