Cel Code 00668 Supply Voltage Terminal 30

Hey guys, this has only happened about 3 times in the last month or so but when im accelerating, the ABS light & Brake light will flash real quick and then Ill here the "Beep, Beep, Beep" then it goes away. I ran vagcom last night and came up with the above. It also said 008 implausible signal intermittent. I think it might be my alternator or ABS controller. Does anyone have any insight, or experience with this, thanks for the help - Jash

With a car 4-5 years old, and an irregular electrical problem, I'd clean all ground contacts (very find sandpaper/steel wool), then put some dielectric grease on the contacts, and tighten down nicely. I believe you'll find several under your battery. This may not be the problem, but couldn't hurt.

Along with cleaning the electrical gound points (which I totaly agree with) ...have you had the the brake fluid system flushed in the past 2 yrs? The ABS system is extreamly sensitive to water/moisture. I would recommend flushing the brake fluid (if its needed).

The next step to take is to inspect/clean all four (4) of the ABS wheel speed sensors. The sensors are simple magnets which dirt and other contamination (ferus) might cause a false reading.

Using "dental flase" as an analogy...take a clean soft rag and (gently) run the rag between the ABS sensor and the wheel speed ring to clean the surface of the ABS sensor.

hey guys I just did a brake bleed about a month ago, also swapped out my brake lines. Do you guys have a pik of the wheel speed ring and wheel sensor showing where they are located, or is it evident when i take the tire off. Im trying to think off the top of my head and can't recall where they are located.

Old thread, but I currently have the same issue. Will try the suggested remedies and post results...

Werid I am also Having the same problem on my 2002 Wagon.

Me too.

Did anyone ever find a solution for this problem?

terminal 30 refers to the ignition switch switched power to most of the electrical system aside from the engine essentials ... this wire feeds into the load reduction relay ... the load reduction relay rarely fails but the ignition switch, it's connector and the t30 wire burns up and will cause this code .... it's very easy to check by removing the lower steering column cover unplugging the ignition switch connector and checking for signs of melting ... good luck !

had similar issue with an 01. unplugging the abs pump and replugging it in seemed to be the last effective thing. and clearing the code every time it came back till it went away. Persistence or luck? I'm thinking the connection needed attention which it got in the way of contact cleaner and multiple insertions.

Hmm...

I've also got low voltage to all the door locks in the ECU logs.

Been an on and off problem for about 2 years, but it's definitely gotten a lot worse. And ya...the engine always starts and runs fine, but other electrical systems (all lights, trip and clock, windows, and locks) all seem to get the problem.

Seems like a short, sometimes everything works fine, and sometimes it doesn't.

That wire and such under the steering column is one of the few things I haven't looked into yet. I'll give it a check. Thanks


PS: Why would a wire be melting? Shouldn't the fuse prevent that? Sounds like a fire hazard.


Oh, and I checked the ABS connectors...at the fuse box on the battery and under the airbox. Still clean and fine from the last time I was in there a while back. All the fuses and lines on the there all seem 100% as well.

Ooh!... I got the same thing. Did you ever find a fix?

BrewCity said:

Ooh!... I got the same thing. Did you ever find a fix?

Click to expand...

Did you check the grounds as indicated?
This is a very old thread to continue. You might start a new one listing the specifics for your car.

Suddenly I got in my Golf Plus 2007 5m1 1.4 TSI 140PH, this ABS fault:

00668 - Supply Voltage Terminal 30
008 - Implausible Signal - Intermittent

many forums advises to check the fuses in that box beside the battery, but that doesn't solve it.

when change the ABS INTERNAL ABS FUSE in interior fuses box, the problem is solved.

please note that, that fuse caused the problem is not burned or cut, and doesn't show any damage sign, maybe is not stable that what is caused the problem.


good day

Badi said:

Suddenly I got in my Golf Plus 2007 5m1 1.4 TSI 140PH, this ABS fault:
00668 - Supply Voltage Terminal 30
008 - Implausible Signal - Intermittent
many forums advises to check the fuses in that box beside the battery, but that doesn't solve it.
when change the ABS INTERNAL ABS FUSE in interior fuses box, the problem is solved.
please note that, that fuse caused the problem is not burned or cut, and doesn't show any damage sign, maybe is not stable that what is caused the problem.

good day

Click to expand...

Recently had the same issue on voltage terminal. Turns out the connectors above the pedals had been tampered with during a diagnosis check. The guys literally yanked their cable out of the diagnosis interface causing some faults in the voltage and power supply terminals. My problem was so bad that the vehicle kept going off at bumps and uneven surfaces causing the steering wheel and brakes to lock. Thank God I wasn't on highways.

Anyway, had the sockets checked out and re-inserted properly. Cleared the error codes and have had no issues since.

Might work for someone.

Cheers.

Good day all,

My Audi a4 1.8t 2006, kept going off when pulling form the red robot or stop sign, will also jerk slightly when driving on the free way, I had the car scanned and got 18010 - Power supply terminal 30 Voltage too low P1602 lower limit reached - intermittent. my battery is fairly new the generator is also good, pls help how to fix this.

Is the 1.8 a diesel??

Have you checked:

rdkern said:

With a car 4-5 years old, and an irregular electrical problem, I'd clean all ground contacts (very find sandpaper/steel wool), then put some dielectric grease on the contacts, and tighten down nicely. I believe you'll find several under your battery. This may not be the problem, but couldn't hurt.

Click to expand...

Yes, old thread but people still get this problem, me included. After chasing it through battery terminals, alternator and voltage regulator, swapping out the ESP and then the ABS modules with @Matt-98AHU , and the codes and beeping still present, I have now fixed the issue.

I removed the Positive connection at battery, and then undid the ten 10mm nuts atop the fuse bar box that sits above the battery. I used scotchbrite to polish every flat metal surface, and a silicon dielectric grease on all mating surfaces, then re-secured all fasteners. The flashing dash CELs are gone, the beeping is gone, and my trip meter and clock don't reset to zeros when I turn off the engine.

Reminds of the Cage mod for the MAF... electrical connections get creeping oxidation and need to brightened up once in a while.

Thank You for posting the solution.
It may help other down the line.