02E Transmission (Direct Shift Gearbox)
Troubleshooting
=> [ Control Module Malfunction Behavior ]
=> [ Troubleshooting, Special Information ]
Special tools, testers and auxiliary items required
• Vehicle diagnosis, testing and information system ( VAS 5051B) or subsequent unit
• or Vehicle diagnosis and service system (VAS 5052 )
Before beginning any service work, the cause of the damage should be pinpointed using "Guided Fault Finding".
Guided Fault Finding is performed using the vehicle diagnosis, testing and information system (VAS 5051B) or the vehicle diagnosis and service system (VAS 5052 ).
Thoughts Before Fault Finding
You should try to create a logical fault finding process.
- Make yourself aware of what kind of complaint is occurring and what fault finding possibilities you have.
• It must also be clear: You should not find faults that others have already found and recognize. Try to see if your problem already had a solution described in => Technical Problem Solving.
• It is possible for you to contact your Technical Support Center (TSC) or the importer in your country. You should use this possibility! It can save you time, effort and money.
• It can also be helpful to be acquainted with the Diagnostic Trouble Code (DTC) entries from other control modules. Always interrogate all control modules. Also, have the BUS topic in mind during fault finding. For example, in an instance like this.
• You should a have diagnostic protocol available when contacting your importer or TSC.
Control Module Malfunction Behavior
The control module works with developed software. This software has the ability to execute electrical functions, monitor and control within milliseconds. Everything modern transmission electronics have going for them is located in this control module. This should also be considered during troubleshooting.
However, no electronics can do what they were not designed to do. Likewise, it is not possible to detect electronically, for example, where the transmission housing is leaking or the oil is leaking. However, it is possible to detect the effects of low oil. A failure in gear monitoring would be recognized causing the control module to respond that both clutches are open (no traction).
You should know this during troubleshooting and also when working with the tester. It is possible that the cause for the malfunction might not be found during Guided Fault Finding.
Aside from the software that makes it possible for the transmission to operate, much was also done to protect the transmission in case of a malfunction (safety functions). And so, when necessary, malfunctions are saved and a replacement program is started.
Control Module Behavior During a Malfunction
If a component in the transmission malfunctions, the control module reacts with a replacement function. In order to protect the transmission as much as possible, four malfunction reactions are differentiated:
1. The malfunction is so minor that it is possible to continue driving with a replacement program while maintaining driving safety. The driver is not notified of this via the selector lever transmission range display. The display shows the selector lever position normally. When can changes in driving behavior actually be detected.
2. Individual lever positions blink in the selector lever transmission range display. This informs the driver that this gear can presently not be selected. An example: Reverse, lever in "R" and vehicle dives backward. If "D" is engaged in this situation, the letter " D" blinks in the selector lever transmission range display. In this case, the control module prevents 1st gear from being engaged to avoid damaging the transmission. The gear is only engaged when vehicle is stopped. If you want to test this, do so carefully!
3. The selector lever transmission range display is completely lit up and blinks. The selector lever position is indicated. An example of this: Transmission oil temperature is too high. Reasons can be, among other things: Towing trailer with too large of a load, auxiliary installations on front of vehicle, lack of cooling air.
4. Selector lever position cannot be recognized, selector lever transmission range display blinks, changes in driving and shift behavior can be clearly detected, reverse not possible. There is a serious malfunction, a sub transmission is switched off, transmission repair is necessary.
Troubleshooting, Special Information
Selector Lever Position Display, No "R"
Simultaneous lighting of all segments of the transmission range selector lever display indicates transmission is in emergency running mode. The vehicle does not drive in reverse.
Tip Function Malfunction, No Gear Selection
- Check the lock washers on the selector lever cable bracket on the top of the transmission.
• The washer - B - can get lost if it loses its residual stress. The - arrow - points to the cable adjustment screw.
Drive Faulty, Insufficient Oil
- Only add oil if it has leaked out, refer to => [ Oil and Oil Level Troubleshooting ] General Repair Information.
No Malfunctions Present
This especially depends on you. Experience shows that often a fault that is attributed to the transmission was caused by other components or units.
It has occurred that poor shifting behavior was a result of insufficient engine air supply. Do not make mistakes like this.
If such faults are to be eliminated, you can work sensibly with the VW tester.
Malfunctions Present
First inform yourself of what the faults stored indicate. The VW tester offers the Guided Fault Finding possibility. You can find many causes of faults when the Guided Fault Finding is used correctly.
Malfunctions Outside Transmission
If, for example, the fault: "Anti-lock Brake System (ABS) signal missing" is stored in the transmission and perhaps another control module also says: "ABS signal missing", you should not continue to suspect the transmission control module is defective.
The entry simply means: The transmission (and possibly other control modules) is waiting for a signal via the BUS but is not receiving it. In this case, the ABS control module has a problem. Under no circumstances should you remove the Direct Shift Gearbox (DSG) mechatronic. In this example, the fault points to problems with the ABS.