Volkswagen Passat Forum banner
1 - 6 of 6 Posts

·
Registered
Joined
·
14 Posts
Discussion Starter · #1 ·
Hi All,

I was hoping for some guidance in solving the error codes I have been getting on my 1.8t 2005 B5.5 Passat with 101k miles. The codes are effecting my CEL and traction control (ESP) light. I mainly need to know what order I should address these issues, and if I am on the right track with what I think is causing them. I have done some research, but there are so many issues related to these codes, I need some help. Bare with me on the length, I am trying to get all my thoughts out here.

Error codes:

18265/P1857/006231 - Load Signal: Error Message from ECU
16804/P0420/001056 - Catalyst System; Bank 1: Efficiency Below Threshold
16795/P0411/001041 - Secondary Air Injection System: Incorrect Flow Detected
16485/P0101/000257 - Mass Air Flow Sensor (G70): Implausible Signal
16486/P0102/000258 - Mass Air Flow Sensor (MAF/G70): Signal too Low
00532 - Supply Voltage B+

Background information:

- For the most part my car runs fine.
- It idles a little rough occasionally, but I have been told this could be aging motor mounts, if I roll forward a half a foot, rough idling stops.
- Around 60 mph (can't say this is RPM related) my engine sounds like it hums a tone/note, but it stops if you accelerate/decelerate 5 mph.
- It jerks a bit if you switch from neutral to drive or reverse to drive. Replacing the hose (mentioned below) has eased this up a bit.
- Occasionally when I start driving it sounds like there is water and rocks sliding down a slide under my dash (unclogging drains didn't seem to help).

In 2011 we had a flood and my car got stuck in it. The MAF sensor, battery, spark plugs, and filters were replaced. This is the only major issue I have had, ther than that I haven't been in any accidents nor have I made any modifications.

Over the past 2 years or so I have had the codes 16804, 16795, and 00532 turning on my CEL. I spent enough money at the dealership and various auto body shops to get a pass on my inspections. The engine codes used to pop up and disappear intermittenly (which I had been told is odd), but as of about a year ago, after resetting them, they always come back after a few days.

Last week I brought my car in to get a CV boot changed (on the front drivers side), after it was done I began getting codes 18265 and 16485 (16485 may have already been there, I can't remember). 18265 seems to be attatched to my traction control (ESP) issue, which is new. I brought it back and they said 18265 was refering to a tire sensor on my rear drivers side. They resistance tested it against the other, determined it was in working order, and referred me to a European car specialist...

What I am assuming is wrong:

Based on what I have read around the net (mostly on this website) I am guessing this is likely related to a faulty MAF sensor, faulty MAF sensor wiring, dirty/faulty combi valve stuck open or shut, faulty ECU, or faulty TCM.

What I have done so far:

Currently 16485, 16486, and 18265 exist alone (for the past few days). But I am assuming the others will be back.

Cleaned my MAF sensor which didn't seem to work. Code 16485 comes back right away, and now he brings his new buddy 16486.

After re-hooking the air box up we carefully analyzed (broke off by accident) the secondary air pump hose that connects to the MAF air box. It was brown and cracked at the point where it broke. I got a new tube and replaced it, but I haven't properly attached it to the secondary air pump yet (temporary duct tape til I get a clamp). This has already alleviated some of the jerkyness

I had autozone check my battery, their reader said "bad battery". I have not had any battery related issues as far as I am aware. I cleaned of some corrosion on the positive terminal. I tested it with a multimete, it reads 12.4v (I'm not sure what's normal) and jumps up to 14+ after starting, so I know its not the alternator.

A couple years back I noticed my passenger carpet was real wet. Didn't think anything of it until doing this research. I unclogged the drains under the car battery. I also pulled up the carpet to check the TCM. The undercarpet was a tiny bit damp in a small section, but nothing too bad. Before uncloggin the drains, I left the carpet up, through a couple rainstorms, and did not notice any flooding. I still here the water sound in my dash once I start driving.

I have also tested all the fuses in my fuse box, they seem fine.

What I think my next steps should be:

Test the MAF wires and the MAF sensor. If its the sensor I can replace it, if its a wiring issue, I have no idea...

Test/clean the combi valve. This seems complicated, but I think I could handle it. Its the first issue I came across that one of the mechanics a couple years ago said "might" be the problem.

Check the ECU relays. I don't know how to do this yet. But I think I could figure it out.

Replace the battery? I don't know if I need to do this or not. I was hoping for some guidance based on what I read on the multimeter.

Summary:

These issues have been around a while and I am not sure I can fix them. But I also don't think the dealership or mechanics I have visited have really helped at all. There is a lot of info online about this stuff, but I am not sure which of it really pertains to me. Any advice or comments on my plan of action, or anything I might be missing would be greatly appreciated. My goal is to spend the least amount of money. So I basically don't want to waste cash/time on a non-issue, if anyone knows that anything I have mentioned is definitely not a problem.

Thanks in advance, I will try my best to answer any questions.
 

·
Registered
Joined
·
295 Posts
Ok I think you are right about the MAF sensor. that would be a good start. The SAIP error will probably go away once the hose is clamped properly. I had most of those same codes and replacing the MAF and going through the PCV system took care of them for the most part.

The water sound seems like a clogged drain. Check air cabin filter, under the battery(again) and under where the brake booster is.

Have the battery rechecked somewhere else.
 

·
Registered
Joined
·
14 Posts
Discussion Starter · #4 ·
Thank you for replying. Do you think it is worth checking the wiring first, or just go straight for the MAF sensor? I ask because I would need to buy about $30 worth of probes and leads, where as a new MAF sensor would cost ~$100. I guess there is no way of knowing if its one or the other until I try something, but if the given issues point to one or the other, I would just do that one first.
 

·
RETIRED Super Stealth Moderator
Joined
·
27,883 Posts
start by replacing the MAF. it is also causing 16804/P0420. the supply voltage code could be caused by a bad battery - have you recently relaced the battery? also, you didn't say where you got the replacement MAF from - was it used, or from a less-than-reputable parts place?

give it a couple of days after replacing the MAF, and then clear codes again and re-read it.

your previously wet TCM can cause the ESP light - take the time to pull up the carpeting, pull the sheathing from around the wires, and physically eyeball each and every wire going to/from the TCU. from what I've seen, TCUs fare less better than CCM modules WRT getting wet, so you may have to replace the TCU.

as an additional note, you ought to edit your location - it simply says United States - so people have a better idea where you are, and maybe someone lives nearby you and is able to help.
 

·
Registered
Joined
·
14 Posts
Discussion Starter · #6 ·
The battery and MAF sensor were both replaced after the flood in 2011. I needed a tow since my car wouldn't run and the mechanic did all the replacements. I do not know what type of replacement MAF it was and the receipt doesn't say, however I know see I was charged about 3x as much as a MAF should cost, 4x if you enclude labor... For a replacement I was looking at Delphi AF10157 Air Flow Sensor or Bosch 0280218100 Air Mass Sensor but I am open to suggestions.

I have not had the ESP issue until I got my CV boot replaced 2 weeks ago. I noticed the passenger side floor being wet about 2 years ago. When I pulled up the floor it was very lightly damp, but I did not notice any damage to the wires. Then again, I am not exactly sure what a damaged wire would look like.

As for my location, hey neighbor!
 
1 - 6 of 6 Posts
Top