jedblack

Hi guys,

So i've done my searching here and i'm a little confused.

My Ignition coil has been replaced twice in the past 15k miles(by previous owner).

I've only put about 300miles on the car since i've had it and today did a long highway trip -- and the CEL started blinking and the engine had no power and was mis-firing like crazy, throttle was almost unresponsive ...etc

I pulled over and had my vag-com with me and this is what showed up...

5 Faults Found:
16805 - Warm Up Catalyst: Bank 1: Efficiency Below Threshold
P0421 - 35-00 - -
17802 - Ignition Coil Power Output 2: Electrical Malfunction
P1394 - 35-10 - - - Intermittent
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-00 - -
16688 - Cylinder 4 Misfire Detected
P0304 - 35-00 - -
16686 - Cylinder 2 Misfire Detected
P0302 - 35-00 - -


Now, at 87k miles the ignition coil was replaced along with the plugs and wires due to the following codes being present.
16685 - Cylinder 1 Misfire Detected
P0301 - 35-00 - -
16684 - Cylinder 2 Misfire Detected
P0302 - 35-00 - -

then at 92k miles the ignition coil was replaced again(under warranty) and the following codes were present.
17803 - Ignition Coil Power Output stage 3: Electrical Malfunction
P1395 - 35-10 - - - Intermittent
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-00 - -
16687 - Cylinder 4 Misfire Detected
P0303 - 35-00 - -
16689 - Cylinder 5 Misfire Detected
P0305 - 35-00 - -

If its my ignition coil again -- then either they used sub-standard/used ignition coils -- or something is causing IC's to burn-up.

could it be related to ICM(pos/pots?) I think they are mounted on the firewall above the air intake filter housing (looks like there is three, black/brown and they are square in shape) not sure what they do....

any suggestions would be GREATLY appreciated.

I picked up(havent installed yet) a new CTS, plugs, wires, -- just dont want to shell out for a new IC and have it along with the plugs and wires burn up again if something else could be causing this...

thanks for the help guys/gals.

tester123

Some procedure to check on coils:

Ignition coils and power output stage are a common part.
Primary resistance of ignition coils cannot be measured.
Secondary resistance must first be measured with the ignition wires connected to the ignition coils via the spark plug connectors of the corresponding cylinder (This measurement will include measurement of the shielded resistances of the ignition wires).
Disconnect 5-pin connector from ignition coils.
Check ignition coils (-N-, -N128- and -N158-)
Pull ignition wires from spark plugs.

Perform a resistance measurement by connecting multimeter between both spark plug connectors of respective ignition circuit to be checked. (plug to plug)
Specification: each 16 to 27 k Ω
If specification is not reached, disconnect ignition wires from ignition coils and perform a separate resistance measurement at ignition wires and at ignition coils.

Perform a resistance measurement by connecting multimeter between both ignition wire connectors and connectors of ignition coil to be checked. (between outputs)
Specification: 8 to 14 k Ω
Perform a resistance measurement by connecting multimeter between both ignition wire connectors and connectors of ignition wire to be checked.
Specification: 3 to 7 k Ω
Replace faulty components if specifications are not reached again.
Checking Ground (GND) supply of power output stage


Further,

Connect VAG1527B voltage tester as follows:
Harness connector

Terminal
Measure to

2
B+

LED must light up.
If LED does not light up:
Check wire connection for open circuit:
=> Electrical Wiring Diagrams, Troubleshooting & Component Locations
Repair open circuit if necessary.
Checking voltage supply to ignition coils
Note:
Voltage is supplied to ignition coils via Fuel Pump (FP) relay.
Test requirement
Fuse for ignition coils OK

Connect VAG1527B voltage tester as follows:
Harness connector

Terminal
Measure to

1
Engine Ground (GND)

Operate starter.
LED must light up.
If LED does not light up:
Check wire connection for open circuit:
=> Electrical Wiring Diagrams, Troubleshooting & Component Locations
Repair open circuit if necessary.
Checking activation
Disconnect connectors from all six fuel injectors. (afterward check DTC memory)

Connect VAG1527B voltage tester as follows:
Harness connector

Terminal
Measure to

3
Engine Ground (GND)

4
Engine Ground (GND)

5
Engine Ground (GND)

Operate starter for a few seconds.
LED must blink (brief blink signal).
If specified values are not obtained:
Switch ignition off.
Connect VAG1598/31 test box at wiring harness to ECM, do not connect ECM => Page AUDI-C5-FU04-24-001-0724-17.

Check following wire connections for open circuit and short circuit to Ground (GND) and B+:
Harness connector

Terminal
VAG1598/31 test box

Socket

3
102

4
103

5
94

Repair open circuit or short circuit if necessary.
If no malfunctions are found in wires:
Replace Engine Control Module (ECM) =

jseklund

Two thoughts come to mind. The procedure for diagnosing misfires often comes down to moving a part from a good cylinder/bank to the cylinder/bank that is not performing to see if the misfire moves with the part.

It seems like your misfires were on cylinders 4 & 2 and then 1 & 2 and then 4&5.

So you look at it and say, I replaced 2 and then 2 went bad again, then I replaced 4 and now that's bad again.

This may not be the case! When you took it in and they diagnosed 4 & 2, they probably moved the coils from, say, 3 & 5 into 4 & 2's position and then the misfire moved, so they replaced 3 & 5 (which were the original 4 & 2 coils).

So, in essence, you may have just gone through 6 or fewer original coils, since you don't state that you ever changed all 6. I say fewer, because they may have just replaced 1 coil pack that was throwing the timing out enough to misfire on another cylinder and the problem went away. I don't know what exactly was replaced, just that they replaced coil packs.

Or, you may have gone through some coil packs and now a POS has died. In the latest readings, it looks like you have a misfire on 1 bank and not the other. You could swap the wiring between the two POS's and see if the misfire moves from bank 2 to bank 1. If it does, you know it's the POS. If it stays on 4 & 5...then it's not.

If it turns out to be a bad coil, and you are afraid the POS is killing packs - do the tests given to you by tester123.

jedblack

I dont have individual coil packs per cylinder -- its one single coil unit.

ie. https://www.carpartsdiscount.com/aut...tml?3593=56962

Since the unit was replaced twice already, and its showing up as failing again-- i'm thinking it may be the POS units - i cant seem to find anything in the manual on how to diagnose these, is there?

tester123

That is correct. Your car does not have individual coil packs sitting on top of spark plugs. The diagnostic procedure in my previous post is applicable to your case. Go through that and see what you come up with.

Note of caution: Checking around high voltage (spark side) of the coils should be done without power connected to the coil. Otherwise, you could damage the test equipment and/or receive a nasty shock!

jseklund

Sorry - missed the engine. I seem to be doing that a lot lately...my bad.

4Driver4

Where did the replacement coil pack come from? If not OEM, replace with OEM.

jedblack

Hey guys,

Sorry i could not respond sooner, thanks for the replies.

@4driver4

I ordered a IC from partsgeek.com -- its said the "Bremi" is the OEM part -- do you know of that is correct?

I'm not sure where/what brand the last two IC's were -- but i'd be suprised of they are true OEM.

jedblack

Hey Guys,

If you see my first post on this thread you'll get some history...

So ever since I bought my wagon I've had a rough idle and the Ignition Coil has been burning up (it's on its 3rd, 2 by previous owner, 3rd by me, all within the last 13k miles). The new coil has about 350miles on it and it holding, but my MIL came back on and I scanned and got the following...


Chassis Type: 4B - Audi A6 C5
Scan: 01,02,03,06,08,15,16,17,18,34,35,36,37,45,55,56,57 ,67,75,76,77

Address 01 -------------------------------------------------------
Controller: 3B0 907 551 BA
Component: 2.8L V6/5V G 0002
Coding: 07252
Shop #: WSC 00000
7 Faults Found:
17931 - Crash Signal from Airbag Controller: Implausible Signal
P1523 - 35-10 - - - Intermittent
16805 - Warm Up Catalyst: Bank 1: Efficiency Below Threshold
P0421 - 35-00 - -
17802 - Ignition Coil Power Output 2: Electrical Malfunction
P1394 - 35-10 - - - Intermittent
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-10 - - - Intermittent
16688 - Cylinder 4 Misfire Detected
P0304 - 35-10 - - - Intermittent
16686 - Cylinder 2 Misfire Detected
P0302 - 35-10 - - - Intermittent
18010 - Power Supply Terminal 30: Voltage too Low
P1602 - 35-10 - - - Intermittent
Readiness: 0000 0000


So, I have a couple questions...

1. I did not drive my car for a couple months and the battery went dead, is that normal or do i have a small short somewhere leaching the battery, if that is considered normal, then would the "P1602" code above be a result of that battery going dead?

2. Could the faulty POS's cause the Ignition Coil to burn up? I'm assuming yes, and that may be why I have a rough idle...

3. I've read that driving the car in this condition could lead to a failure of the catalytic converter(s), could that be what "Warm Up Catalyst: Bank 1" DTC is? is that a failed CAT or a failed oxygen sensor or both?

TLR
Could I indeed have two failed POS's(Is that a realistic hypotheses?), could it be causing my IC to burn up and cause a rough idle, is there a way to diagnose the POS, and finally... What are the part numbers for the POS's and is there a place where you know that i can get them relatively cheap?

Sorry for the long winded post, but this is been a thorn in my side for some time now...

thanks for the all the help...

The codes that keep reappearing are(in no specific order)...

16805 - Warm Up Catalyst: Bank 1: Efficiency Below Threshold
P0421 - 35-00 - -
17802 - Ignition Coil Power Output 2: Electrical Malfunction
P1394 - 35-10 - - - Intermittent
17803 - Ignition Coil Power Output stage 3: Electrical Malfunction
P1395 - 35-10 - - - Intermittent
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-10 - - - Intermittent
16688 - Cylinder 4 Misfire Detected
P0304 - 35-10 - - - Intermittent
16686 - Cylinder 2 Misfire Detected
P0302 - 35-10 - - - Intermittent
16685 - Cylinder 1 Misfire Detected
P0301 - 35-00 - - - Intermittent
16689 - Cylinder 5 Misfire Detected
P0305 - 35-00 - - - Intermittent

bigdadi

Would it be caused by MAF or IAC?