1998 Volkswagen Passat Check Engine Light

P0133 - Oxygen Sensor Circuit Slow Response (Bank 1 Sensor 1)
P1519 - Malfunction In IAC Valve Circuit

Diagnostic fault codes never say to replace parts or that they're bad. They only indicate the circuit or system that needs further diagnosis. The code 1519 is a perfect example. It doesn't specify what the problem is, just that that's the circuit that has the problem. The Engine Computer controls idle speed by adjusting the amount of fuel spraying from the injectors and the amount of air going through the idle air control valve. A problem with the IAC valve could allow in more air than desired resulting in an excessively lean mixture or one that's too rich. If the passage is blocked by carbon not enough air will go in and the mixture will be rich. Oxygen sensors only detect unburned oxygen, not fuel, so they don't report a rich condition, but they normally switch between rich and lean a couple of times per second, and when they fail to go lean, that's when the computer assumes the mixture is rich.

Failing to go lean over an extended period of time could set the code 133. That would not be due to a defective oxygen sensor. It's simply reporting what it sees. I would have code 1519 diagnosed first. Your mechanic will erase the codes, then see if any come back.

P1519 Intake Camshaft Contr, Bank1 Malfunction

Bank 1 is the side with #1 cyl. Passenger side.

Thomas

I'm showing code 1519 is related to a problem with the idle air control valve. What is leading you to something with the camshafts? Are those solenoids or camshaft position sensors?

I come up with a totally different description, but regardless, I'd need to read the exact code description to get a better idea of how to proceed. There can be dozens of codes related to a camshaft position sensor and they all mean different things. Some will describe an electrical problem such as an incorrect signal voltage, break in one of the circuits which could include a wire, a connector terminal, or the sensor itself, or some other defect causing a loss of signal. A different code could mean the signal is perfect but it is not in time with the signal from another sensor, in this case the crankshaft position sensor.

"Intake Camshaft Contr, Bank1 Malfunction" is the correct definition of P1519

Thomas

The codes were all standardized among all manufacturers beginning with '96 models with the On-Board Diagnostic emissions system, version 2, (OBD2), but it appears as usual Volkswagen has to be different and do things differently than everyone else. "German engineering" is definitely not "better"; it's just different.

The code doesn't say much. Is that "intake camshaft control"? What are they controlling? What does the code mean? Is it referring to an electrical problem with a sensor? A solenoid? Does it refer to a mechanical problem? Was this some early attempt at variable valve timing?

What are the diagnostic steps? Doesn't do much good to have a code but no idea what it means or how to diagnose it.

Simple system to diagnose when you have the info and know how the system works.

I was just letting you know that the code description was correct.

VW is not the only one that has different code description from "standard" definitions.

Daleh5, if you need info, you can contact me via my profile.

Thomas

The point is we DON'T have the info and we DON'T know how the system works. Some of us read these forums to learn about unfamiliar things. Is there a reason it needs to be kept top secret?

My apologies. I thought you guys had Mitchell at your disposal.

I just checked and they have a similar listing for that code: Bank 1 Camshaft position adjustment malfunction

I don't know how to link the info (from our Shop Account) to this website.

Haven't been getting forum updates via email any more. Someone is restricting my input, so I figured I would restrict my help.

Thomas

I understand your thinking. Contact Mike with any problems you're having. I haven't been able to get into Mitchell, ever. I always get an error message on the password page, on both of my computers. I also haven't been able to post photos or drawings since they changed the site layout a couple of months ago. I was using drawings from my automotive electrical web site, then since I couldn't post them I was posting links to pages on my site, and they don't like me doing that either.

A lot of people have disappeared since they have to keep on signing in over and over. If you type a response that takes too long you'll lose everything when you try to post it unless you copy it first. All the advertising makes the pages take a painfully long time to load too. I think the frustration has taken its toll, but they always resolve the problems eventually.