1Z is no longer working correctly, multiple errors

Hello,

I think my 1Z is slowly getting infested with gnats. I have a lot of errors in the error memory.

539 Donors Fuel Temperature.
30 KS after + static.
Okay, I can get rid of that with a new MSW that I still have.

777 Accelerator Pedal Position Sensor G79.
156 KS after + occasionally.
If that thing fails, it should actually go into emergency mode, right? It's never happened so far. According to the diagnosis, the sensor is also functioning properly.

519 Donors Intake Manifold Pressure G71
156 KS after + occasionally.
The intake manifold pressure is also within the normal range when I run the diagnostics, so it's within the expected parameters. That's strange, isn't it?

741 Brake pedal monitoring.
155 implausible signals, sporadically.
No idea. Brake works, brake lights too!

1117 Load Signal Generator Terminal DF.
27 implausible signal, static.
I once swapped the distributor for one with a free-running clutch. It's possible that the distributor firing signal isn't the same, but I'm not sure why.

'Definitely, with these issues, I can't maintain a consistent speed; it feels like the engine momentarily cuts out and loses fuel intermittently, every few seconds.'

Once the sporadic errors are resolved, it will work again. But the strange thing is, the things aren't actually broken. I have no idea what's going on???

You can ignore the 1117.
I have all of those too, because I used to have them. I have no idea where it comes from or what it's supposed to do, because I can't tell any difference whether the code is in memory or not.

m;

I once heard that the DF signal is used to slightly increase the fuel injection amount, so that the alternator can provide more power when many consumers are turned on in winter. I hope I haven't messed this up.

Cabriodriver wrote:

.... Once the sporadic errors are resolved, it will work again. But it's funny because the things aren't actually broken. I have no idea what's going on???

Thinking is a privilege... Or??

What does "Kuzschluss nach Plus" mean?
If you've found this answer, it should be clear where you need to look.

All your mistakes can clearly be traced back to the same root cause.


EDIT: You would have found this by using the search function: /viewtopic.php?t=12414&highlight=kurzschluss+nach+plus

Well, electricity isn't really my strong suit, sorry. I would be very grateful if you could help me. That's what the forum is for, isn't it?

I've used the search function and already read the relevant threads. However, I'm not sure if that applies to my situation. You seem very certain. I'm not. And that's for the following reason:

If I understand correctly, are you suggesting that the problem is due to a missing ground connection, which is caused by a blown ground wire and is related to the engine control unit (ECU)? (I haven't installed any tuning boxes or made any other modifications to the engine...)

But first: the fuel temperature sensor is definitely defective; I know this because it's been faulty for a while.

Secondly, the sensors for the accelerator pedal and intake manifold pressure, as well as the brake pedal monitoring system, are only intermittently present and not consistently, and when they are present, the readings are also inconsistent. I regularly check the error memory. How is this possible? Could it be a loose connection? Just like that, out of the blue?

Cabriodriver wrote:

... If I understand correctly, are you suggesting that something is missing?

Sure.

Quote:

... which is attributable to the engine control unit...

NO!

Not necessarily. Similarly, a fault in the mass airflow sensor (MAF) or the engine block will produce the same error code.

As mentioned in the thread above:
Try measuring the ground mass in the engine wiring harness first. A broken wire within it would have the same effect as a burnt-out conductor.

Quote:

But first: the fuel temperature sensor is definitely defective; I know this because it's been faulty for a while.

I don't think so...

Quote:

Secondly, the sensors for the accelerator pedal and intake manifold pressure, as well as the brake pedal monitoring system, are only intermittently present and not consistently, and when they are present, the readings are also inconsistent. I regularly check the error memory. How is this possible? Could it be a loose connection? All of a sudden, just like that?

Exactly... All of a sudden, like that!

I always used to say to my relatives: "...yesterday, Grandma was still alive, and today we are carrying her to her grave..."
Even if it sounds macabre, that's just the way it is.

Okay, let's talk about your problem. I doubt that your fuel temperature sensor is actually defective. In 75% of cases, you've likely had a problem with the ground connection on the engine block or with the connection between the ground and the control unit for a longer period. An undefined ground potential can prevent the temperature from being measured correctly by the control unit, and the sensor will then be reported as defective. High resistance connections (e.g., due to water ingress) develop gradually and initially cause intermittent issues, but eventually lead to a sudden failure. Just like you.

Simply put, you're currently experiencing an intermittent connection (somewhere in the wiring harness, especially the ground connection).

"Bitte gib mir den Text, den du übersetzt haben möchtest."

"Bitte gib mir den Text, den du übersetzt haben möchtest."

Well, I actually didn't want to mention this, but I don't use VAGCOM.

@Bertil
I'm a bit surprised that you're so certain about my fuel temperature sensor. I'm also experiencing this jerking issue due to the ESP, and that's why I've already replaced the MSW (Multi-System Wiring) twice. Every time I have one particular MSW installed, the error code appears, but not with the other one. That's why I'm absolutely certain that the sensor is defective.

You are probably right about that, considering the other sensors. I will definitely check that out.

Regarding the communication problem: with good adapter hardware, such as the Profisystems, everything functions as desired.

However, the numerous errors suggest a missing ground connection in the control unit or problems within the wiring harness.

Best regards, Rainer.

Regarding the communication problem: with good adapter hardware, such as the professional systems, everything functions as desired.

However, the numerous errors suggest a missing ground connection in the control unit or problems within the wiring harness.

Greetings, Rainer

I completely agree. As I mentioned, I'm going to try to figure out the apparent mass issue. Thanks for your help.