silverd2

If I'm not mistaken, that code 17087 (P0703) is a regular diagnostic test the car does on every new start up...a preset fault that should erase when you press the brake pedal.

Guys99A8

I got the battery fully charged and it started. Yea, I was getting depressed.

Thanks for the brake code info. I had that addressed a while back and hopefully it just needs to be cleared as the brakes and brake lights work.

Now I have to find the short on the leveling sensor and address the air flow sensor.

It is also burning rich, would you happen to have the specs for that so I can adjust it? I won't be able to receive my manual for a week or so. I'm assuming that type of info is in the manual.

At this point, do you think it’s safe to erase the codes then see what comes up? I'm wondering about the air flow positioning monitor as it says the reason was also low voltage.

And while I’m at it, can you tell me where the ground to left side leveling sensor is? I have you on the line and if it is an easy question for you...

silverd2

Yes definitely erase all codes. The ones that still apply will come back in 2 or 3 driving cycles.

There are no user adjustable fuel mixture settings. The ECM does all that through 3 main inputs >>

1. Major adjuster: The MAF (mass air flow sensor) which either works right or not, but can be cleaned (MAF cleaner or similar) IF the "hot wire" has accumulated dirt.

2. Mixture trim: Front 02 sensors (usually shot by 100K miles, with or without codes)...if they have failed, the default setting is the rich end of the trim map.

3. Mixture adjuster: Coolant temperature sensor and NOT the one that sends temp reading to the gauge...there is a separate one that send signal to the ECM...gauge could be correct, while the ECM's CTS is incorrect. If it reads too cool, it will send a rich mixture signal to the ECM, thinking it's still in warm up stage.

There are 2 level sensors for the headlight controls, one on front left and one on the rear left (no right side sensors). Neither one has it's own ground wire...all 3 wires from each go directly to the headlight beam adjusting module, which is hidden behind the b-pillar trim, inside at the rear base of the passenger's front door jamb...odd place, but that's where it is, if you need to get to it.

Guys99A8

You have been a real life-saver; you and everybody who posted. I think I got it from here. I will articulate and summarize what happened so others can benefit as well.

I would like to be able to upload pictures though. I am following the directions on the web pages and the file sizes are under the limit. Is there something I am missing? This happens on both web sites so I know I am doing something wrong.

Back to fault codes.
I'm thinking I've probably had these fault codes for a while and just didn't know it as I just got the Ross-Tech software. I say this because the car appears to be running normally. At first it ran a little noisy, lifters or fuel injection, but it quit after running for a little while. It may have had something to do with the air flow flap positioning motor which kept coming up but quit and has corrected itself. It appears that was a power issue also.

One of the dealers should have picked up on one of the fault codes though.

Other than me swapping out all the control arms and the tie rods and the car needing an alignment, it appears to be OK.

As to fuel mixture, I will go through everything you told me. I replaced the 2 front oxygen sensors about 3 or 4 months ago or about 8, 000 miles. I haven’t changed the rear sensors yet.

I cleared the codes and took the car out 3 times, but still getting some mainstay fault codes.

1 Fault Found:
00776 - Level Control System Sensor; Left Front (G78)
31-00 - Open or Short to Ground

I will follow your advice.

Everything works, brakes, ABS, lights, etc. Since the brake switch error code appears to be part of the automatic transmission cluster (?), it may be due to my rebuilt transmission. I’ve had it rebuilt 3 times, the 3rd because they messed up on the second. I know, I’m pressing my luck. I have to be careful not to jam it in reverse too quickly as it will thud into gear. Long story.

Address 02: Auto Trans Labels: 01L-927-156.lbl
Part No: 4D0 927 156 BH
Component: AG5 01L 4.2l4V USA 1313
Coding: 00002
1 Fault Found:
17087 - Brake Switch (F)
P0703 - 35-00 - Electrical Malfunction

The other 2 mainstays are for the Seat Belt Switch and Central Locking Pump Run Time Exceeded. From what I was told by one of the mechanics, I need swap out the unit the belt locks to. The airbag light is on in the instrument panel and will not clear. I was told the passenger side air bag doesn’t work. I am not so sure now and I will track that down also. As for the locks, I have a leak in the line and I need to get inside the door panels. I think I know where that is due to some prior work done on the car.

I think I remember seeing this one alone the way as to the switch and I will retrace my steps.
1 Fault Found:
00592 - Seat Belt Switch; Passenger (E25)
32-00 - Resistance too High

1 Fault Found:
01367 - Central Locking Pump Run Time Exceeded (Likely Leak)
35-00 - -

silverd2

Thanks for the update...always of interest.

If the P0703 is persistent, it may very well be a problem with the brake light switch. If the switch is good, hitting the brake pedal once should erase that code.

The air flow code was just part of the climate control system...nothing to do with the engine...V71 is the flap motor that controls fresh air intake and recirculate for the AC. Engine noise lessening was likely just getting oil flow and heat back into the lifters...not uncommon with 32V motors, having larger "old style" lifters.

Your level sensor is likely bad or has wiring problem near the sensor...I'd do a good visual on that. It is very exposed to the elements and damage. The control units never go bad.

As for "rich running": Do you smell rich (sweet) exhaust when the engine is fully warmed or are you getting bad gas mileage or what?
When 1st started, the exhaust should smell rich (normal), but not if you've been driving a while.

Guys99A8

As to gas mileage, I used to get close to 500 highway miles on a 21 gallon tank averaging around 70 miles per hour. Now it is around 400 highway miles. City miles are also down.

The rich smell is when I start it and after I driven it for a while and it is stronger than what it used to be. I've also noticed the after part more often which has lead me to believe I don't have the right mixture. Most of the time, the smell is stronger right after I start it and less after driving, but sometimes it seems to be the same. I just ran it for 15 minutes and I can defiantly smell gas out of the exhaust pipe. I’ll pay more attention to this to see the difference.

The car has always periodically blows a small cloud of white smoke right after I start it, not water vapor but exhaust smoke. It clears up right away and the car does not smoke at all other than that. However, it seems to be happening more often, not a lot, just more often.

I chalk that up as having gas built up somewhere in the system. I swapped out the front O2 sensors but not the back. The smell is the same. I’m thinking the 2 rear O2 sensors also need to be changed?

Also, I drive between California, Oregon, Washington and Nevada through a lot of different elevations, air pressure, temp, humidity, etc.

As to the brake light switch, when you say hit it once, you mean using it in normal driving would suffice, or do I need to do it while hooked up to the VCDS? I had an issue with this before, and it turned out, or so I was told, if one of the lights goes out, it would trip the warning light. Swapped out the lights, everything works, no warning light. This was about 5 months ago.

As to the level sensor, I have been doing some work around it (swapping out the lower control arms) maybe I hit something. I will look.

Thanks for telling me about the air flaps, I thought it was on the air intake to the engine.

I got a lot of studying to do.

silverd2

The little puff of smoke (more likely light blue? ...oil. If it was fuel smoke it would be very black) is common on these engines..usually the valve stem seals, being that you have 32 of em making it more likely to let a little by...all it takes is one. After starting they get lubed, swell a little and still do their sealing job. I wouldn't worry about them unless you have consistent "unknown source" oil loss (1 quart every 1K miles or so).
I just about totally got rid of that with my car by running a rubber treatment through my oil just once...most oil leak treatments contain this, but most use something that softens the rubber and may seal at 1st, but then allow accelerated wear of the seals. What I used is the same stuff I use on ANYTHING rubber (even revives old o-rings in other systems)...it's a plasticizer...replenishes exactly what rubber looses with age, so any swelling it causes is because it's adding volume to the rubber the right way. It's called "AT-205 Re-Seal"...miracle stuff. I ran an 8oz bottle with my oil just once for the last 500 miles before a change and have never seen smoke on start-up again. I did the same in a high mileage Passat with 30V V6 and the oil usage dropped from 1 qt per 1K miles to about 1/3 qt. They should pay me to advertise for em

The rear 02 sensors really don't do anything but trip a CEL once in a while. The do NOT have any effect on fuel mixture ever...they are just there to report how well the front ones are doing and report the efficiency of the catalytic converters...they are just monitors, not adjusters.

The brake light switch code is (according to Bentley) supposed to set the "test" code when the ignition is turned on each time, but erase (with ignition on) the first time to press the brake pedal. If it does not, there's some kind of problem with it...but if your brake lights work and touching the pedal disengages cruise control, it should be working correctly basically working...but it also send a signal to the TCM (trans module), so the fault may not be with the switch itself(?)...that's why it's a "P07**" code..."700" codes are generally reserved for Trans components.

Guys99A8

Interesting. I’ve had a couple of the dealers tell me because it is an inverse engine, it is supposed to burn oil occasionally, and that it was normal. The puff of smoke may have some blue, again; I will pay better attention. I do know that it smells like gas. Like I said, it doesn’t happen all the time. I’ll try the additive.

I’ve seen a lot of posts regarding “Sea Foam.” What is your opinion on that? As a rule, I do not put any additives in the car and I only run Chevron with Techron high test for fuel. I use Texaco second.

As to the brake switch, like I said, I’ve had the transmission rebuilt 3 times and there may be an issue as to some signal coming from its ECU(?) to the switch. My cruise control is relay is bad. This is one of those times I am questioning one of the dealerships. They told me it would cost around $1,500 to replace it. I know better now, and I will swap that out also. As much driving as I do, it will help cut down on the speeding tickets as it is very easy to go over the limit and not realize it.

What would happen if I tried to erase codes while the motor was running?

silverd2

"Inverse engine"?, I've never heard it termed that way...I assume that they mean overhead cam as opposed to a pushrod engine? If so, I don't get that reasoning. According to Porsche (and they put this right in their owner's manual for the 928...I had 3 of em in the past), with the introduction of their 32V V8 (up from original 16V), simply because of twice the number of valves and twice the chance of seepage, "you may see a little more oil usage over time"..."and not to be concerned, unless it's excessive".
With my D2, I have never had to add oil before the next change..5-7K miles.

Techron is absolutely the best fuel system additive out there. I add that to my fuel (if non-Texaco premium) occasionally as an injector and general fuel system cleaner. I'd use it more often if it weren't so expensive, in bottle form.

I, too am not too big on oil additives, using only quality synthetic. The AT-205 Re-Seal, I only used after researching it and seeing such impressive results on my wife's ex-Passat...AND I only used it coming up on an oil change (they recommend it be run about 500 miles to possibly fix even a leaking rear seal), so I could get it back out after it had time to do it's job, which it seemed to have done. It is very thin and not a good lubricant, just a rubber seal treatment.

As for erasing codes with engine running? I've never tried it with VagCom and a regular hand held code reader won't let you even read the modules while engine is running..just ignition on, motor off. Set codes are checked and sometimes shut off (erased?) according to the number of drive cycles (drive cycle = engine off-engine on each time) diagnosed, so I've never tried (or had reason) to do it with my VagCom.