'98 a6q aha.
This happened all of the sudden.
The car ran fine one minute and the next time I went to crank it, it sounded like the battery was dying.
It was making that straining, non-rhythmic sound as the starter was turning over.

I finally got it to start and the car sounded like it was misfiring and having a hard time idling.
The check engine light went from steady to flashing and back.

I figured the battery was the culprit so I purchased a new one (a few days later.)

After a few days, I got the new battery and hooked up vag-com

These were the codes:

10 Faults Found:
18010 - Power Supply Terminal 30: Voltage too Low
P1602 - 35-10 - - - Intermittent
16795 - Secondary Air Injection System: Incorrect Flow Detected
P0411 - 35-10 - - - Intermittent
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-10 - - - Intermittent
16687 - Cylinder 3: Misfire Detected
P0303 - 35-10 - - - Intermittent
16690 - Cylinder 6: Misfire Detected
P0306 - 35-10 - - - Intermittent
18014 - Rough Road/Engine Torque Signal from ABS: Electrical Malfunction
P1606 - 35-00 - -
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-00 - -
16687 - Cylinder 3: Misfire Detected
P0303 - 35-00 - -
16690 - Cylinder 6: Misfire Detected
P0306 - 35-00 - -
16686 - Cylinder 2: Misfire Detected
P0302 - 35-00 - -
Readiness: 0000 0000

After replacing the battery I cleared the codes and performed a throttle body adaptation.

I started the car and let it idle a few minutes.
Initially, it sounded good. Even after the higher rpm warmup cycle.

I drove around the block and when I got back the idle was not consistent.
It was dropping from 900 or so to 500 and back. Eventually it dropped lower and almost died.

I was afraid to drive it until I knew what was going on.

Today, I cranked it to do some more diagnostics, and again,
it sounded like the battery was dying, and cranked with that non-rhythmic sound.

Trouble light came on again- flashing then back to steady.

Here are the codes this time:

7 Faults Found:
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-10 - - - Intermittent
16685 - Cylinder 1: Misfire Detected
P0301 - 35-10 - - - Intermittent
16687 - Cylinder 3: Misfire Detected
P0303 - 35-10 - - - Intermittent
18014 - Rough Road/Engine Torque Signal from ABS: Electrical Malfunction
P1606 - 35-00 - -
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-00 - -
16685 - Cylinder 1: Misfire Detected
P0301 - 35-00 - -
16688 - Cylinder 4: Misfire Detected
P0304 - 35-00 - -
Readiness: 0110 1101

Notice the readiness this time??

What is going on?

Oh, one more thing.

Maybe I have just not noticed this before, but the solenoid that closest to the fuel rail on the right
(sorry i don't have the manual to get the name) sounds like it is hissing, or there is air in the fuel rail.

I have done the test including fuel injectors and solenoids, and it sounds like they are all clicking.


What do I do?

Thanks for the help

 

I have cleared the codes 3 times, not 2.

Above I listed times 1 and 3.

Here they are again in order.

1:

VCDS
Windows Based VAG/VAS Emulator
Version: Release 908.1
www.Ross-Tech.com
Dealer/Shop Name:
Workshop Code: 000 00000
Diagnostic Trouble Code Report
Friday,25,December,2009,13:14:57:52858
VIN: License Plate:
Mileage: Repair Order:
Control Module Part Number: 4D0 907 551 AH
Component and/or Version: 2.8L V6/5V MOTR AT D01
Software Coding: 06252
Work Shop Code: WSC 02325
10 Faults Found:
18010 - Power Supply Terminal 30: Voltage too Low
P1602 - 35-10 - - - Intermittent
16795 - Secondary Air Injection System: Incorrect Flow Detected
P0411 - 35-10 - - - Intermittent
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-10 - - - Intermittent
16687 - Cylinder 3: Misfire Detected
P0303 - 35-10 - - - Intermittent
16690 - Cylinder 6: Misfire Detected
P0306 - 35-10 - - - Intermittent
18014 - Rough Road/Engine Torque Signal from ABS: Electrical Malfunction
P1606 - 35-00 - -
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-00 - -
16687 - Cylinder 3: Misfire Detected
P0303 - 35-00 - -
16690 - Cylinder 6: Misfire Detected
P0306 - 35-00 - -
16686 - Cylinder 2: Misfire Detected
P0302 - 35-00 - -
Readiness: 0000 0000

2:

8 Faults Found:
18010 - Power Supply Terminal 30: Voltage too Low
P1602 - 35-10 - - - Intermittent
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-10 - - - Intermittent
16687 - Cylinder 3: Misfire Detected
P0303 - 35-10 - - - Intermittent
16690 - Cylinder 6: Misfire Detected
P0306 - 35-10 - - - Intermittent
18014 - Rough Road/Engine Torque Signal from ABS: Electrical Malfunction
P1606 - 35-10 - - - Intermittent
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-10 - - - Intermittent
16687 - Cylinder 3: Misfire Detected
P0303 - 35-10 - - - Intermittent
16690 - Cylinder 6: Misfire Detected
P0306 - 35-10 - - - Intermittent
Readiness: 0110 1101

3:

7 Faults Found:
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-10 - - - Intermittent
16685 - Cylinder 1: Misfire Detected
P0301 - 35-10 - - - Intermittent
16687 - Cylinder 3: Misfire Detected
P0303 - 35-10 - - - Intermittent
18014 - Rough Road/Engine Torque Signal from ABS: Electrical Malfunction
P1606 - 35-00 - -
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-00 - -
16685 - Cylinder 1: Misfire Detected
P0301 - 35-00 - -
16688 - Cylinder 4: Misfire Detected
P0304 - 35-00 - -
Readiness: 0110 1101


Thanks..

 

What's your alternator voltage output reading?

 

bad ignition control module?

 

The alternator output was above 13V. I don't remember the exact voltage.

Jeff, would the ICM be the same thing as the power output stage?

Thanks.

 

anyone have any ideas on this?

 

Vacuum leak?

 

So yesterday after work I stopped by the audi dealership and picked up 2 meters of vacuum hose for around $12.
I was going to use the silicon rubber from ecstuning, but shipping was more than the tubing.
Anyway, I changed all of the hoses and gave it a test run.
It made a huge difference.
Before, the car was sluggish and felt like it was starved for fuel.
Now, it is peppy and responsive. Like it is running on full power.

However, this did not solve all of the problem.

The problem is the idle. If the car just sits there with no action on the accelerator, the idle is steady with a slight "miss" every 2 seconds, or so.

If I give it a good revving, the rpm's will come down to around 300 and try to stall, then it will level out.

When I'm driving, if I reduce speed rapidly and go from 3000 rpms to a slow turn, the car will stall. (the turning causes more strain on the motor from the power steering pump)

I have set the readiness 3 times and it will not stick.
I have also performed multiple throttle adaptations.

I don't remember which sensors, but I do remember the secondary air injection and one of the oxygen sensors were not "ready"

The MIL is no longer showing, or at least is hasn't in the short testing time.

The temperature sensors seem to be performing correctly.

So what things to I need to check to solve the idle problem?

Are there other tests I can perform?

Thanks.

 

Check the resistance on the o2 sensors. They should be 20 ohms or less. Anything more should indicate bad o2 sensors. Here is a little write up.

http://www.vaglinks.com/Docs/Audi/Mi...esting_DIY.pdf

Also you can check the measuring blocks 34 and 35. 34 is aging test for B1-S1 and 35 is for B2-S1. Engine RPM should be around 2000 and the temp should be above 260 degrees C. The response time should be from 0.4 to 1.0 second. If they check out, then the test should complete and say okay.


One more thing for AHA is that I think you have Idle Control Valve. (ICV) Looky here for cleaning instruction.

http://www.audiworld.com/tech/eng88.shtml

 

Thanks for the help.

Can't work on it again until thursday. I'll post some results then.