P1606
 

So I got the P1606 code - VVEL issue, limp mode. The first time it happened, I was able to reset the ECU and was able to get home. Next day, the code came back. I ordered a used VVEL module from ebay, swapped it out. Code was still there and still in limp mode. I tried to clear the code with a scanner, disconnecting the battery, and using the ignition on/accelerator presses method (5 times) and still couldnt clear the code.
After that, I went and got a new VVEL relay and swapped that out, still have the code. Tried both old and "new" VVEL modules with the new relay and no luck. So as I stand, still getting the code and still cannot reset the ECU.
I could have very well received a bad VVEL module from Ebay, but why cant I reset the code?

Anybody have any ideas whats going on?

Have seen the other threads on this issue? Someone was saying they replaced both relays?
And maybe you need consult 3 to clear this code?

Sorry can't help much as there's not much info out there about this fault.

Also try G37 forums as well.

And in EC.pdf see under contents..

ADDITIONAL SERVICE WHEN REPLACING
CONTROL UNIT (VVEL CONTROL MODULE) .......18

Theres only a handful of threads concerning the P1606 code on both 370z and G37 forums. Im not sure what one relay has to do with another though?

I had waited overnight with the "new" module installed, hoping that the ECU does its thing with updating, but it still had the code. So I put back the original module in with the new relay, hoping perhaps that the module was good, and relay was bad. Ill start her up in a couple hours and keep my fingers crossed.

Its pretty scary driving and all of the sudden the Z goes into limp mode.

Check the power to the control module itself with a 12v 50w light globe. Compare light brightness with just connecting to battery.

That is a bad idea. He needs to use a VOM meter. A light will light up and mislead you. Seen some horror stories of that in my technician days. One guy had to go to court over it for a misdiagnoses.

Your correct but you can misdiagnose with a VOM as well.
Best to load power supply and check voltage at same time at the VVEL connector.

You may be referring to the low wattage test lamps.
Not ideal for testing high current ccts.

While it may not be the best method to check for high resistance wiring, it is not a bad way to do it. As with any other test procedure, one needs to be able to interpret the results properly. The "light test" is not perfect (a marginal wiring problem may not cause enough change for eyes to notice) but works well for finding higher resistance wiring problems.

So..... I checked the Vvel fuse...its one of those fusible links..that was good... cleaned the ground with a wire brush... installed a new vvel relay...swapped out with a different vvel module. Visually inspected the harness under the battery tray..Still a no go...
I dont know how I would test the module under load as the connector from the harness is enclosed.

At this point I'll order another module... I'll have to test the other relay before I order another one.
I hope it's not a bad harness..

Assuming the 50W mentioned above is what the module pulls under full load, you don't have the have the module connected to perform the test. Poke a nail, stiff wire, or similar conductor into the harness connector pin and attach light to it. Ground the other side of the light.

50W @ 12V = 4.2A, so it's not going to be pulling a lot of current but you might want to put a 10A (or 6A slo-blo)* fuse in series with the light - just to be on the safe side.

*Incandescent bulbs have a high inrush current so you need a "big" fuse or one that will survive the initial current draw.

Hi Bunk,
Have you tried driving the car after you first replaced the module? Some times this can clear codes.

And does the car have any mods like Uprev or ecutek?

After I replaced the module and then the relay, the car is still in limp mode. Wouldnt go over a few mph. I do have an ecutek tune.

Did you check with the globe that the module is getting power. Use the ground pin on the connector and not the battery for car body.
From FSM pin 14 is GND. Check pin 8 has power on it. The VVEL module seems to isolate supply to motors on pins 1 and 13 via relay. If the module is not working this relay maybe off. But you should see pin 8 with power with module removed and ignition on.

I havent tested it yet, was trying to research the pin layout on the connector. This is perfect. Thanks!

VVEL reference starts at FSM EC-597 2010 revision.

Show what you should see on each pin.

But see EC-606 shows module pinout.

Finally the code is gone. I checked power to the vvel harness and it was good. Tested all fuses, they were all good. Even with a 3rd VVEL module I still had the code. Uninstalled and inspected all connections and reinstalled the original VVEL module. It started fine with no codes. Time to do some short drives.

Also look at the possibility that this issue is related to the ecutek tune.

I read on another post that someone had to revert back to stock ecu before this error code disappeared.

I still have my EcuTek maps ...at least I can scroll through them, but whether or not they corrupt, I couldnt say. The person who had to swap out their ECU probably had a bad ECU?

In my case, Im guessing that I had a faulty relay, either one of them or both, since I ended up replacing both, and a bad module from ebay, and since everything is working as normal now, Im not inclined to swap them out to test them :rofl2: I was starting to freak out that I may have had a shorted engine harness.

I do have to admit though, that this problem sorta forced me to read the FSM, you kinda pushed me to do that..lol And omg, its a plethora of info if you really read it! :tup:

edit: for anybody going through testing the harness, in the FSM, the pinout for the VVEL Module is not the pinout for the harness, its the pinout for the Module. So if youre testing the harness, all the pins are in "mirror", so pin 1 one the harness is the first row, first pin on the RIGHT, etc...just look at pin 14 on the harness and in the FSM, its a blanked out pin, no actual connection, and youll figure it out....it might be pin 26 thats blanked out... youll have to do the research yourself, Im done with reading the FSM for a while now...lol

If its working and stays that way for a few days you should be good to go.

If Nissan has one good thing in there cars its the Hitachi modules.

For future P1606 people, check the VVEL relay box and connections.

So the code came back, and swapping modules and relays or resetting the ECM didnt work. Fiddled around with the VVEL relay box. When I removed it from the bracket, I noticed that the bottom of the relay box wasnt clipped in properly. This allowed the wire harness alot of play and must have caused bad connection to the connection pins. After I snapped the relay box bottom back, I was able to get the Z started up with no code.

I've seem relays cause issues when they are loose in the car and bouncing around. The shock on the relay will cause the contacts to open for a few milliseconds but is enough to trip a error code. Other cases with age the electromagnet isn't strong enough and any little bump with cause it to open. Easy to find by tapping with a large screw driver with car running. Sometimes corroded connector or faulty crimp. could be many other reasons.
No easy way to fix, you just need to keep looking and rule things out.
At least you now know the area where the issue maybe.

How hard do you have to tap on the relay when the engine is running? I tried that yesterday, but maybe I wasnt tapping hard enough. I also tried to push down on the relay.

Depends on where you hit it (parallel or perpendicular to the movable contacts) and how marginal the relay is. You can give them a pretty good whack without doing any damage; they get bounced around quite a bit in normal use.

Good to know. I was afraid to tap too hard and damage the relay. They werent cheap..lol

Well, don't go banging on them with a hammer but a good rap with a screwdriver handle should be OK. You just want to simulate what happens when driving, not an asteroid impact. :)

If they are new relays you don't need to check anything.

I was referring to old defective relays.

if had this issue 3 times now the 1st 2 times just bought a used vvel controller off ebay and bam it worked... but this last time it didn't... btw i had an ecutek tune. both times had to put back the stock rom in order for the vvel controller to connect. this last time had to bring her to the dealership and it was the canbus receiver not communicating with any vvel controller i had both old and new. that was July 2020 now here it is Oct 2020 and still on the stock rom, no issues and car runs like a champ but in stock form... kinda wanna put my tune back on and see if it really had anything to do with the vvel controller issue...

Help with the P1606 code
 

I saw this existing thread and to be honest I’m completely lost. So if anyone could explain it like I’m a 5 year old that would help!

I recently had my 2010 370Z roadster just shut down while driving home. I luckily was able to turn it off and in again and everything was fine.

A week later the check engine light came on.

I’ve always wanted to get an OBD2 reader, though I have zero idea how to interpret its results. So I have a screenshot of what it’s showing me. Can anyways tell me what it means?

Thanks in advance.

Did you ever end up finding a fix or have someone help you figure it out? I have a 2010 370z base coupe and I just had the same issues last night.

P1606 error
 

My 2010 370z convertible was stuck with a P1606 ERROR Code. I disconnected the battery, changed the relays and ordered the modules (didn't install them). When taking the stuff apart to get this module numbers I noticed my battery was 8 years old. My car started with it, but I wondered if it had enough current on start up for the air dampers since they are on a 50amp circuit. So, I bought a new battery and installed it. Code went away. I did have the old battery tested and was told it was "weak" but I am not sure these guy's test. So, I got a new battery anyway from Costco ($140). Seems have worked. I hope this helps. I also hope this is the problem. Time will tell :)