Quote:
If you have an automatic transmission on your B5, take a minute, lift the hood, identify the sealing bellows where the A/C core comes through the firewall, and use a zip tie to make sure the seal is tight. This bellows is above the passenger's feet, below the cabin air intake and filter. I had to join two zip ties together. Here is my tale:
- While driving at freeway speeds, the car suddenly jerked, followed by two more jerks. Afterwards, drove okay, though seemed to have problems downshifting - possibly explained as transmission going into limp-home mode.
- After allowing car to cool, again drove at freeway speeds, where car again jerked several times, then seemed to not go into overdrive. Set the following trouble codes:
Thursday, 15 December 2005, 17:09:10
VAG-COM Version: Release 504.1-D
Control Module Part Number: 8D0 927 156 J
Component and/or Version: AG5 01V 2.8l2V US D89
Software Coding: 00000
Work Shop Code: WSC 00000
2 Faults Found:
00652 - Gear Monitoring
- 27-10 - Implausible Signal - Intermittent
00268 - Solenoid Valve 6 (N93)
- 31-10 - Open or Short to Ground - Intermittent
- On audiworld.com, received the following post:
"according to ETKA your transmission has three solenoid valves. Part number#:01V 927 331. I don't which one is faulty on yours or how many are bad. They list for $73.53 each, to give you an idea. So, if they end up replacing the solenoid it will be the cost of that, transmission filter & gasket, fluid, and labor. ECS sells the filter and gasket for $29.95 and the fluid for $12.95/L. It may cost around $500...I could be off on that though.
"the solenoid will be located in the valve body of the transmission just above the transmission pan. So, they have to remove the pan and filter to get to it. It will call for a new tranny filter and fluid also, which is not a bad idea at this point considering the year of your car and the issue you are reporting. I have heard of this being the only problem in some cases and changing out the solenoid fixes things. However, I don't know if that will be the case for you..we can only hope."
- Reputable German repair shop Frank's Automotive says their live-data system indicates car shifts into overdrive, but has issues with reverse and first. Reverse doesn't work, first has hard shifts.
- Reputable transmission shop Sierra Clutch and Transmission says there are four $240.00 solenoids and three $75 solenoids - they can't tell which is N93. They pulled the pan, and there are no metal shavings - indicating it is either a solenoid, or a broken seal passing pressure. The hard shift into first was explained as the transmission going into limp-home mode, and raising internal fluid pressures. A rebuild at the transmission shop is under $3,000, plus hard parts. The evidence in the pan shows no hard part issues. They recommend going to the dealer for diagnosis, possibly $200. The dealer may also have a Technical Service Bulletin regarding the issue.
Lasher Audi Dealership found the following:
- Selector is in correct gear. No more diagnostic available without disassembly.
- There are issues with knowing what's going on in valve body and, could still be an issue with clutch pack.
- It's coming down to a teardown. Dealership charged me $74, and recommended Aamco on Arden. Dealership washed and vacuumed the car.
- Called Aamco, didn't catch agent's name, discussed, felt marginalized. They wanted $138 for diagnostic.
- Dropped off at Sierra Clutch and Transmission. Barry says teardown costs $595, promised to have it torn down by Friday.
- Barry called to say he had two guys out sick with the flu - he's a little behind
- Barry called to say the clutch pack for first and reverse was fried. He estimated $2,495 for the rebuild, however, they also required $312 for three galloons of Audi's transmission fluid. I gave the okay. Barry says one of his employees broke a rib snowboarding, and he's behind.
- The transmission's finished, but they can't clear the trouble code. They are putting it on a truck and taking it to Neillo Audi, who is backed up and will see it Thursday.
- Car continues to set N93 troublecode. Neillo dealership advised Sierra to replace transmission valvebody.
- There is a chance a failed solenoid caused the clutchpack failure. Barry is trying to find a reasonably-priced replacement valve body.
- Barry at Sierra sourced a remanufactured valvebody, charging me their price, $400. The valve body includes the electrical connector. After installation, transmission is still setting N93 trouble code. Sierra describes the trouble code as P0758 for Solenoid B.
- On boot, the transmission cycles through the solenoids for a test. Likelihood of new valvebody setting same troublecode is nill.
- Sierra again communicated with Niello dealership. Niello advised checking eletrical continuity between processor and transmission. Sierra returning car to Niello for pin-point tracing of wiring. "Brian" is the Niello service writer. They start at 1.5 hour book rate for pin-point test.
- Because of the car's failure mode - cruising at highway speeds with sharp jerks - there is a chance eletrical failure caused the transmission to spontaneously shift into reverse, causing the clutch pack failure.
- Barry: "Every now and then we get one that just bites us in the butt."
- Left message for Niello Service Writer Brian, advising car also has intermittant failures with cruise control and heater solenoids, both of which share electrical connectors in the area of transmission controller.
- Brian called to say they had found plugged drain in transmission ECU compartment. Says sunroof drains feed into this area, but water was not exiting. Transmission ECU was wet. They advised changing out the ECU and harness, which will require removing the dash. Audi lists the ECU for $1,900, and Niello typically charges an additional 20%. Round-trip labor on the dash is ten or twelve hours, at their $105 US per hour shop rate.
- I put it on a flatbed truck and dragged it home. The dealership charged $115 to find the flooding, the tow company charged $123 for the transport.
- The Neillo dealership dug out the TCU, and it's flopping around on the floor. I took a look, and it's dry. Also, they broke a tab on the trim cover for the eletrical connectors. I guess you can't get good labor at a dealership when you're only paying $105 US per hour.
Label on the transmission computer:
BOSCH
Getriebesteuerung 085
0 260 002 408 GS8.33
ZF 0 501 005 747
OOOO 8DO 927 156 J
001 724D0889
GCBC17960377 Made In Germany 664
Label on the connector:
81
284 336 356
873
GCBC004807 0 260 002 408
- I got some free time to read the TCU codes. It set N89, G93, N92, and N93. The G-code seems out of place, but they all trace to the same connector on the valvebody.
- Curiously, they're all intermittant. The shop said it was setting the code immediately.
- I cleared the codes, and carefully drove around the block, not going faster than 15mph. Afterwards, I read the TCU, and no trouble codes were set.
- Called Neillo, to get them to confirm the failure mode. They won't return my calls.
- Neillo dealership said the sunroof was draining into the compartment for the transmission computer. Actually, the sunroof drains to the exterior of the A-pillar, outside the passenger compartment.
- Where did the water enter? I'm thinking it's the A/C drain.
- Why didn't the water drain out? The dealership said the right front floor drain was clogged. I am unable to find a drain. The floor has some places where there are openings going back into the body - perhaps the drains are in there.
- I lifted the carpet where the transmission computer lives, and the underside is soaking wet. The actual transmission computer is in a weather-sealed box. I propped up the carpet, away from the floor, so there's some air circulating to dry it.
- Three of the four questionable transmission pins are on the bottom side of the harness connector. Water in the connector could cause them to short to each other. The connector has what might be water scale where it plugs into the TCU. There are no water markings on the outside of the TCU case.
- Cautiously, I drove down side streets to the grocery store, about a three-mile trip, at speeds under 35mph. Afterwards, I read the TCU, and no codes were set.
- So, I have a dilemma: the transmission, etc., just cost me $3,300. Do I spend another $550 on a junk-yard computer, or do I risk another $3,300 on the computer I have?
- I might open up the TCU, and take a look to see whether I can find damage, specifically, where the electrolyte of capacitors might have leaked onto the circuit board.
- Received the following post on audiworld.com:
"Open up that TCU, and make sure it is thoroughly dried out. Get some contact cleaner, and clean up the contacts on the harness/TCU.
"Next find the source of that leak. Remove the battery, and test the drain at the bottom of the battery tray. It's common for that to clog, and if it does, I'm fairly certain you'll end up with water in the footwells. Apparently there is also a drain for the HVAC system on the passenger side of the car...check that one too. One of those two is your culprit.
"And as you now know, the dealer is an idiot for suggesting it was the sunroof drain.
"Once you've tested, located, and fixed the drain problem, dry out the car completely, put everything back together, and monitor for codes daily (or twice daily) for a month. Assuming no more codes are thrown...I would probably forget about the new TCU. If you still encounter a problem, then you can revisit the issue, but I think you'll be okay. Cross that bridge when you get to it.
"Thank #@$%! you towed that car out of that shop. They were bleeding you for money with their guesses and conjectures. Doesn't sound like there was any end in sight if you had continued following their recommendations (well, short of you emptying your bank account)."
Replied:
"Sounds like a plan. I'll have to bend tabs to get into the TCU, but it shouldn't be a big deal."
- Drove the car to the gym, a distance of ten miles. The car set no transmission trouble codes.
- Drove the car to work, 25 miles each way. I drove during the height of rush hour, so I wouldn't have an opportunity for fast speeds. After work, checked trouble codes, and there were none for the transmission.
- Removed battery and associated brackets. The two drains were clogged, but not enough to cause a leak into the passenger footwell. The drains exit under the car behind the engine. Reviewed the Bentley manual for information on the A/C evaporator drain.
- It was raining. I went out to where the car is parked in the driveway to examine the A/C evaporator drain. By chance, I felt the carpet to the right of the drain, and it was wet. Water was dripping out of the heater box.
- At the base of the windshield is a plastic piece with weatherstripping. This weatherstripping has deformed, allowing water to drip into the cabin outside air inlet. This inlet is directly above the cabin inside air inlet. Water has been dripping through, onto the carpet, soaking the transmission computer's compartment.
- Now, all I gotta do is fix it.
- Working my way up from the wet area, I found the lower windshield valence was distorted, right in an area where the leak would go through the air inlet and soak the carpet. The local recyling yard had a replacement.
- The car is leaking some kind of oily fluid. I can't find the leak. I'll start monitoring, and see which level goes down.
- I'm leaving little dots on the driveway. They're just to the right of the driveshaft.
- So I crawled underneath and took a look. I can't see where anything's leaking.
- The fluid is the color of oil, but kind of watery. Neither the water or oil levels are going down.
- On these Audi ZF transmissions, there's no dipstick. You can't check the fluid without a lift and a special tool. The transmission fluid is a proprietary color, and probably not the usual pink.
- The transmission started slipping. I think I now know what's leaking fluid.
- We're within the warranty period, but the shop can't get me in this week.
- Dropped off the car. They had to run it on the lift for twenty minutes before the link manifest, but it's in the junction between the transmission and the rear housing. It's very small, but they're unable to tighten the join enough to stop the flow.
- They're going to remove the transmission and reseal the housing.
- Finally got it back. No charge. I'd like to emphasize Barry and Sierra Clutch and Transmission did a great job, and even with the delays, I recommend them for German ZF transmission repair.
- I've been driving it for a week, and it's sweet.
- Two months have gone by, and everything's fine. No fluid leaks, no trouble codes, and beautiful shifts.
- I cleaned the car today. Afterwards, we drove to the store, and Beth (my wife) commented on water dripping on her foot (it's sandal season).
- The glovebox is still off, so she tried to reach up and feel from where the water came, but couldn't isloate it.
- Set up a test, where I laid upside-down in the passenger footwell, while Beth sprayed a jet of water from the hose at the base of the windshield.
- After several minutes of focusing water around the windshield, I was unable to feel water in the passenger footwell. We opened the hood, I resumed my position, and she began spraying water around the firewall.
- I finally felt a few drops. Beth focused her spraying, and it became a torrent.
- It's the seal around the A/C evaporator. It's still tight where it seals to the firewall, but it's loose where the high and low pipes come go through.
- I put two zip ties around the seal to give it a little help, then repeated our failure mode where Beth sprayed water on it.
- No leaks.
- Rainy season is predicted to start Monday. We'll see whether there're any leaks.
- Had two days of hard rain. Today's weather is dry. I dug up the transmission computer, and everything's dry. I'm gonna call it "fixed."
Came across this while looking up some ATF stuff for Russell's A4 thread.
It just reminds me time and time again that one must be careful with some shops. What was originally intended to be a routine transmission rebuild can turn into a nightmare.
Just an interesting read...
