Allroad 2002 2.5TDI Quattro AUTO TRANSMISSION Question

[bigandy82]

First post... heregoes.

Hi, I have a condition with my gearbox which I'vebeen trying to find an explanation for for some time now... I'vesearched more posts than I can think of but nothing pinpoints thesymptoms that my car has.
The car is an AudiAllroad 2002 2.5TDI Quattro.
Engine code: AKE
Gearbox code: EYJ (Ibelieve)


Symptoms:
when I drive thevehicle 1^st gear changes to 2^nd fine. When Ichange from 2^nd to 3rd it revs high before it engages, theexact same for 3^rd to 4^th then it's finefrom 4^th to 5^th. This doesn't happen all thetime but it does happen a lot. To me it feels like an electricalfault, not mechanical.


I've scanned it withVCDS and have found the following fault code:


Address 02: Auto Trans Labels: 01V-927-156.lbl
Part No: 4Z7 927 156 H
Component: AG5 01V 2.5lTDI RdW 2121
Coding: 00001
Shop #: WSC 00000
VCID: 4B95AD5C79C81779CBD-515E

1 Fault Found:
18265 - Load Signal
P1857 - 35-10 - Error Message from ECU – Intermittent


Has anyone ever experienced this or can at least point me in the right direction of fault finding to the answer?

Andy.

[Scott K]

http://www.audi-sport.net/xf/threads...ittant.218846/
Have a look here. Seems to be related to alternator connection to gearbox, MAF or injector harness??
The part number 4Z7 927 156 H is the gearbox transmission module.
This is the Ross Tech advice.
http://http://wiki.ross-tech.com/wiki/index.php/18265/P1857/006231
Good luck.

[Tel2]

I have a somewhat similar problem which I have been unable to match anywhere. I even took it to an auto trans specialist this week who is also baffled!

The problem almost only occurs when the vehicle is cold. After a few miles it goes away. The are times when it refuses to change from 1st to 2nd automatically. You can get to 30mph and it still won't change. As soon as you flip it to manual mode you can change it with no problems. It also has the same delays between the gears mentioned by bigandy82. This usually only applies to the lower gears and it will rev between gears. Again this tends to disappear as the vehicle warms up.

There are no warning lights. All the gear lights on the dashboard are displayed correctly. Once the code 01119 came up (transmission shift-range gear position signal). After deleting the code it has never come back.

The auto trans specialist originally thought it was going to be the "switch" from my description but after test driving it 3 times from cold he is convinced it is not as all the lights are correct and there are no fault codes. His guess is that it is the gearbox ecu but he does not deal with them! That is an expensive item to buy and non trivial to get at under the driver's seat so I am looking for anyone who has come across a similar problem and can confirm the correct resolution.

The gearbox is a ZF5HP19 on an Allroad 2.5TDi 2005 C5

Thanks for all and any help.

[Audi A6 Allroad]

Hi Andy, my A6 ALLROAD was also experiencing the same problem with the delayed gear changes after a cold start. I observed it all started when at the local garage the mechanic decided to put a thicker Engine oil 5W40 because of the high mileage (mine was at 188000 then. If you can check for any oil leaks especially engine oil and transmission oil leaks just under the car only then you can start to get hold of the problem. I controlled the Oil leak both the engine oil and the transmission oil by using Wynnes Stop Leak oil additive from Halfords. It's about £6 a can of additive which you will be using just in case there is an oil leak. For the transmission Leak you will have to mix the Transmission Leak Stop oil additive while topping up the transmission oil, it's £6 a can. Lastly use Castrol Edge 5w30 fully synthetic engine oil on each oil change. I followed this after controlling the oil leaks and my car is driving better than before. I hope it helps. Remember, the thicker engine oil takes longer to warm up especially in the winter. Cheers

[Scott K]

Those engine oils will both be the same in cold conditions as they are both 5W. The second number is the viscosity at 100C I think.

[Tel2]

Thanks for the suggestion. There are no oil leaks from either the engine oil or the transmission oil. Your post did raise the question in mind though on whether I should change the oil for a thinner one and see if it makes any difference but the subsequent post from Scott K seems to indicate that the oil is the same in both cold and warm conditions.

Since my last post I have tried to isolate which ECU may be at fault. One of the tests I performed was to disconnect the battery for 6-8 hours and then reconnect it, effectively doing a cold re-boot of the module. This stopped the problem for around 2-3 days so it would seem to indicate a fault in one of the ECUs. Which ECU is at fault is the problem as I understand they are all constantly talking to each other and affect each other's control. Any ideas would be helpful, thanks.

[Scott K]

Try cleaning the MAF or removing it and see how it runs. It might be giving bad readings to the ECU.

[Tel2]

Can I do that by just disconnecting the sensor and seeing if it changes anything? There are no error codes showing which might indicate a problem with the MAF.

[Scott K]

Can try that. The original post listed the faults and I think the load signal can sometimes be from the MAF as it supplies info to the ECU. The MAF comes out quite easily and the wires are often coated in carbon so a clean can help.

[Audi A6 Allroad]

Hi, There should be no harm in putting a good quality fully synthetic oil (closer to 5w30) to ease off the idle speed of the engine immediately after a cold start in the morning. In A6 ALLROAD, the system set gear change intervals are pre set at around 0-5mph for 1st gear; 6- 15 for 2nd gear but if you're going uphill it will hold until you reach 20mph. The 3rd gear should be switched automatically at 21mph; 4th gear at 31mph and the 5th gear at 41mph unless you choose to switch the gear in manual mode. In both modes the gear change intervals will remain nearly the same. The very Common Mistake is when the driver start over riding the gear change from the button at the steering wheel while the car is being driven in AUTOMATIC. This can lead to the fault code suggesting a problem with the "gear range/interval".