Do you already know which vehicle component is hidden behind the term fault memory? Are you guys familiar with the different diagnostic equipment? Good! Now the only question that remains is whether this error memory can also be read out and then deleted again without the help of additional technical devices. For all those who have also already asked themselves this question, we provide the corresponding answer in the following article.
So, how can the fault memory be read and cleared even without a diagnostic device? In many common vehicle models, it is possible to read out the fault memory without the aid of a diagnostic device by retrieving the stored messages via a type of “Morse code” – generated by the flashing of the engine control light. In the case of BMW and VW vehicles, there are also additional options for reading out and even deleting the memory. These methods make use of menus that can be accessed via the instrument cluster, air conditioning or navigation system, for example.
But how exactly does reading the memory with the “Morse” method work now? Instructions for this option as well as the various alternatives at VW and BMW can be found in the following sections. In addition, for all those who have not yet had so much to do with the fault memory, we clarify basic questions about this useful component and at the end of the article we present an alternative for using the memory with a diagnostic tool.
What is the error memory and what data is collected?
If you have not yet dealt with the topic of error memory and its reading or deletion, it is probably difficult to imagine at first how this should be possible without technical aids and why it is important at all to check the memory at regular intervals. For those of you who are also asking yourselves exactly these questions, we have compiled the relevant answers and information in the next sections.
Basically, the fault memory in your car is part of the complex overall system consisting of various control elements and numerous sensors, all of which are regularly checked via the so-called OBDII system. This system refers to an on-board diagnostic system that checks the critical components for functionality during ongoing vehicle operation and detects any irregularities and records them accordingly. These error messages are then stored in the error memory and can be read out via this if required.
In principle, all faults and technical defects in the vehicle are stored, including problems with exhaust emissions, faults with the axles or brake discs, a flashing engine control light or problematic oil or coolant levels. Each error that occurs is assigned its own four-digit numerical code during diagnosis, which is then stored in the memory.
However, not every stored error is actually relevant, as incorrect measured values may also occur under certain circumstances and cause an error message. Therefore, a basic distinction is made between static and sporadic faults, with sporadic faults being automatically cleared when they no longer occur beyond a certain number of drive cycles. Switching the ignition on and off again is considered a driving cycle.
If you want to get an overview of the current state of your vehicle, it is recommended to read out the memory and check the stored messages. If you set yourself a regular time period for this check, after which you retrieve the memory, you increase the likelihood of being able to detect and rectify faults and problems in your car at an early stage, before they develop into serious damage that can then cost a lot of money to repair. Therefore, it is useful for every vehicle owner to know about the function of the fault memory and use it accordingly.
Basic principle of readout without diagnostic device
If you have decided that you want to read out the fault memory of your vehicle, but do not want to spend any money on it for the time being, there is a method that allows you to access the data without technical aids. This works via a kind of “Morse method”, which allows you to display the saved messages in encrypted form.
However, the basic prerequisite for the applicability of the “Morse code” is that your vehicle must have an electronic accelerator pedal, which should already be installed in most current models, for example in Volkswagen models since 2001. If you own a VW vehicle, you can also see from the corresponding indicator light on the dashboard whether your model is really equipped with this accelerator pedal. The relevant symbol represents the letters “EPC” – for Electronic Power Control – for all vehicles of the VW Group, which are highlighted in yellow when they light up. As soon as you turn the ignition key in the lock, all installed warning and indicator lamps should light up once briefly, so that you can then easily check this. Since the electronic accelerator pedal is connected to the vehicle’s control units via a sensor, it is in principle possible to retrieve the stored messages via this. Further, crucial to this method is the check engine light, which is also located on your dashboard and is usually represented as a yellow stylized engine on a black background. By flashing them, the corresponding digits of the error codes are formed, with a total of four digits denoting a complete code. These digits are played back one after the other, with one flash indicating the number one and ten flashes indicating the number zero. Thus, almost innumerable codes can be formed, the meaning of which you can usually display via various lists and compilations on the Internet. For example, code range P0115-P0119 represents engine coolant temperature problems (P), range P0230-P0233 denotes a fuel pump fault, and digits P0780-P0784 indicate a gear shift defect.
If you want to try this procedure, you first have to fully depress the brake and accelerator pedals with the car switched off. In the case of an automatic transmission, the lever must be positioned on “D”. Then turn the ignition key to the “ignition” position, whereupon the engine control light should flash and play the digits for the stored error code at short intervals. Each code repeats itself a few times so that you have enough time to write it down.
Here is an example of a “mored” error code:
10 x flashing – PAUSE – 2 x flashing – PAUSE – 6 x flashing – PAUSE – 7 x flashing
This results in code P0267, which stands for a problem with the injector.
Special features for Volkswagen Group and BMW models
Now that we have taken a closer look at the general method, we would like to go into a little more detail for the common models of the manufacturers BMW and Volkswagen and present you with further possibilities of how you can not only read out the memory of these vehicles without a diagnostic device, but also – at least for certain error messages – delete it.
BMW
If you are the proud owner of one of BMW’s models, you have the option of activating the so-called secret menu to read out various messages from the fault memory, in addition to the general method via the check engine light, and access the stored data. Depending on the model and year of manufacture of the vehicle, different procedures are required to activate the secret menus and make the information available there. In the following, we would like to introduce you to three different ways to unlock the menus, and in the last section, we will provide you with a summary of the menu items that can be selected.
First of all, the activation option via the reset button of the trip kilometers should be mentioned here, which can be used for the E39, E46, E85 and Z4 models, for example. In a first step, you have to set the ignition to level 1 and press and hold the reset button for the trip odometer – usually the left button – for about five seconds. The trip odometer will be reset initially, but it will reappear as soon as you enter the corresponding menu. After holding the button for a long enough time, you should automatically get to menu 1. Now you have to press the same button as many times in a row until you get to menu 19. It is important to press the button shortly after each other and not to take a break, otherwise you will have to start from the beginning. If menu 19 is active, the messages “L off” or “L on” appear alternately on the display after a short moment, corresponding to “Lock off” or “Lock on”. Now you have to wait for the moment when the display “L off” appears and then press the left button again, which will unlock the secret menus and you should automatically land in the first secret menu. If everything has worked, you can now also scroll through the secret menus 1-21 with the trip odometer reset button and call up the information relevant to you. Activating a specific menu and the corresponding submenu is very simple and is done simply by waiting a short time as soon as the desired menu appears on the display. To exit the selected menu, you have to press the already known button again and hold it for a few seconds until you get back to the main menu and can navigate through the menus there.
Another way to unlock the secret menus is for example for the E38, E60 and E65 models as well as for the E81 and E90 models via the instrument cluster. To do this, the ignition must first be switched on and the right-hand button – known as the Check Control button – on the instrument cluster pressed. First the message “Check Control OK” appears and about 10 seconds later the message “Test No. 01”. As soon as you can read this in the display, you must press the left button so that the chassis number is displayed. The last seven digits of this number are then used to form the checksum, whereby letters can simply be ignored. Here is an example: The chassis number DG24387 results in the checksum 24. Once you have calculated this sum, you have to press the right button repeatedly until the message “Test No. 19” appears instead of “Test No. 01”. Afterwards, the left button must be pressed again until the displayed number corresponds to the cross sum calculated from the chassis number, i.e. 24 in our example above. After pressing the right button again, the menus should now be unlocked and usually do not need to be unlocked again. The operation of the various menus and submenus is analogous to the method already described above, whereby here the right button of the instrument cluster represents the “navigation button” instead of the reset button for the trip kilometers.
The third way you can activate the secret menus in your BMW is relevant for all vehicles that are already equipped with the navigation system I-Drive. And here, too, there are differences depending on whether an I-Drive CCC or an I-Drive CIC navigator is installed. For the slightly older CCC system, proceed as follows: by clicking Menu, you should get to the basic navigation system screen, where you should then hold down the I-Drive button for about 10 seconds. This is followed by a combination of turning the knob several times in this order:
– Turn 3x to the right
– Turn 3x to the left
– Turn 3x to the right
– 1x turn to the left
– 1x turn to the right
If you now press the button again, you should get directly to the secret menu.
And for the newer CIC navigation systems, the procedure is similar and also consists of a sequence of different turns of the knob. But first you have to select the submenu “Navigation” in the main menu, but do NOT press it. Then push the I-Drive button forward for 10 seconds, then release it and turn it in that order:
– Turn 3x to the right
– Turn 3x to the left
– 1x turn to the right
– 1x turn to the left
– 1x turn to the right
Once you have done this, the “Office” menu should be selected and as soon as you press the I-Drive button again, the navigation system should not switch to the “Office” menu, but to another submenu, which is called the “Service” menu. At the very bottom of this menu, you can then unlock the secret menus under “Settings”.
Overview secret menus
Now that you have surely found a way to unlock the secret menus for your BMW model, it is of course still interesting to know which menus are actually available and what information you can get in the respective submenus. Therefore, for the sake of completeness, the following list provides an overview of all available menus, whereby you will be particularly interested in menu 14, since you actually only want to read out the error memory.
But here now first the entire menu display:
Menu 1: Vehicle information
– Menu 1.0: Chassis number
– Menu 1.1: K-number speedometer combination
– Menu 1.2: BMW part number instrument cluster
– Menu 1.3: Coding/Diagnosis/Busindex
– Menu 1.4: Date of manufacture vehicle (format KW/J)
– Menu 1.5: Hardware Stand
– Menu 1.6: Software version
– Menu 1.7: Coding data
– Menu 1.8: CAN
Menu 2: Instrument combination test, i.e. all indicator lamps and displays flash simultaneously and all pointers are moved
Menu 3: Service interval display
– Menu 3.0: Service interval basis – calculation in liters
– Menu 3.1: Days remaining until inspection
Menu 4: Consumption
– Menu 4.0: Current consumption liters/100km (0128 corresponds to 12.8l/100km here)
– Menu 4.1: Consumption in liters/hour
– Menu 4.2: Average consumption in liters
– Menu 4.3: Average path 1 (Calculated from 4.2)
– Menu 4.4: Average consumption 2 in liters
– Menu 4.5: Average path 2 (Calculated from 4.4)
Menu 5: Range
– Menu 5.0: Average consumption liters/100km as basis for range calculation
– Menu 5.1: Current range in km
Menu 6: Tank information
– Menu 6.0: Tank capacity left/right (234123 corresponds here to 23.4 l left and 12.3 l right tank)
– Menu 6.1: Total tank capacity
– Menu 6.2: Tank content display Tank gauge
Menu 7: Motor/speed information
– Menu 7.0: Instantaneous coolant temperature
– Menu 7.1: Instantaneous outdoor temperature
– Menu 7.2: Instantaneous motor speed
– Menu 7.3: Instantaneous speed
Menu 8: Values from menu 7 in hex format
Menu 9: Onboard voltage
– Menu 9.0: Current on-board voltage in volts
Menu 10: Country coding
Menu 11: Unit coding
– Menu 11.0: Time unit (24h or 12h)
– Menu 11.1: Displacement unit (e.g. km/h)
– Menu 11.2: Temperature unit (e.g. °C)
– Menu 11.3: Consumption unit (e.g. L/100km)
Menu 12: Last ride
– Menu 12.0: Average speed of the last trip
– Menu 12.1: Travel time of the last trip (hours:minutes)
Menu 13: Test of the on-board computer chime
Menu 14: Error memory
– Menu 14.0: Number of stored error messages (maximum 10 pieces)
– Menu 14.1-14.10: Display of stored error codes
Menu 15: Port assignment
– Menu 15.0-15.11: Port
Menu 16: Dimensioning
– Menu 16.0: DIMMRAD-CAN
– Menu 16.1: PHOTO ADC
– Menu 16.2: DIMM-PWM-S Z
– Menu 16.3: DIMM-PWM-D K
Menu 17:
– Menu 17.0: DISP-HEIZ
– Menu 17.1: NTC1 NTC2
– Menu 17.3: CONTR-PWM
Menu 18: CC Test
– Menu 18.0: CC Test
Menu 19: Lock menus (Lock on, Lock off)
– Menu 19.0: here the sum of the digits must be entered (see above)
Menu 20: Correction factor consumption
– Menu 20.0: Correction factor consumption
– Menu 20.1: Setting 10s digit
– Menu 20.2: Setting 100s and 1000s digit
– Menu 20.3: Saving and displaying the set value
Menu 21: Reset
– Menu 21.0: Software reset – corresponds in its effect to disconnecting the battery
As already mentioned, you only need menu 14 to read the messages stored in the error memory, whereby a maximum of 10 stored errors can be displayed there. The first number in submenu 14.0 corresponds to the total number of messages and the respective submenus up to 14.10 represent the corresponding error code. You can make a note of it and then check the code lists available on the Internet to see what problem it points to.
If you want to delete the memory after reading it out, you can do this via the reset menu no. 21, whereby you have to go to the submenu 21.0. If you activate this, the software is reset, which is similar to disconnecting the battery and resets the error memory accordingly. It is important to note, however, that not all faults in all ECUs can be cleared via this menu on most vehicle models, so safety-related messages such as problems with the airbag, transmission or engine will remain and can only be removed once the damage has been repaired.
Volkswagen
While the fault memory of BMW models can be read out via the so-called secret menu, as described in the previous section, owners of various Volkswagen models, such as the Golf or Passat, also have the option of displaying relevant fault messages via the air conditioning system.
To do this, you must first turn on the ignition of your car and then press and hold the “Recirculation” and “ECON” buttons of the air conditioner simultaneously for at least 3 seconds. Now the first possible error code is displayed directly. By pressing the “Warmer” key, all other stored errors appear one after the other. If all stored codes have been output, the display shows the message “000”. If no error at all is stored in the memory from the beginning, the display “444” appears directly.
Once you have read out all the existing messages and noted down the corresponding codes, you can also delete the memory via the air conditioning system. To do this, simply press the “ECON” key again for at least 2 seconds after the end of the output – i.e. when the “000” display appears. As confirmation, if the deletion was successful, the message “444” is now displayed. To exit the error memory mode after reading out and deleting the memory, simply press the “ECON” key again briefly.
Alternatives to readout without device
Despite all the possibilities of reading and deleting the error memory without additional tools, we do not want to completely refrain from presenting you with the alternatives. These are worthwhile, for example, if you want to use other methods of vehicle diagnostics in addition to simply reading out the memory, or if you want to check several vehicles at regular intervals.
Basically, you need a suitable readout adapter for vehicle diagnostics using the device, as well as a mobile device on which you can display the error messages stored in the memory. An example of a well-functioning diagnostic tool is the Carly app, which we will introduce to you in more detail in this section. This app offers both reliable vehicle diagnostics and – depending on the vehicle manufacturer – various other applications, such as emissions testing or the coding of individual components and control units. With the help of the modern Bluetooth adapter, which automatically sets the appropriate configuration according to your car make and model and ensures instant and secure communication with your mobile device through the wireless connection, you can read fault codes from all relevant control units and receive both the original code itself, as it would be received by the specialist workshop, as well as an additional interpretation of the severity of the present problem. Deleting the saved messages is also possible with the Carly app. In order to detect any sporadic errors that are currently stored in the memory but have no relevance for the functionality of your vehicle and are deleted after a certain number of driving cycles anyway, you can first delete the list of messages after an initial readout of the error memory and then perform a new diagnosis. All further indicated problems are then to be taken seriously in any case and require a need for action on your part.
You may now be wondering what costs you can expect to incur when purchasing and regularly using the Carly app, and whether they are actually worth it for you. In principle, you will only incur one-off costs of around 60 euros for the necessary adapter, which in many cases – depending on the vehicle manufacturer and the relevant specialist workshop – already corresponds to a one-off diagnosis by a professional. If you want to continue using all the available functions of the Carly app without restriction, you will have to pay a monthly license fee of just over 6 euros for the use of the full app version “All brands”, which will be billed annually. However, if you can do without certain functions, you may also be able to use the free Carly App Lite and thus save the additional monthly costs. In addition to the wide range of options as well as user-friendly operation, another great advantage of the Carly app is that it can be installed on both iOS and Android devices, while many other apps are limited to one of the two operating systems and thus may be of limited or no use to you as well.
When should you visit a workshop in spite of everything?
However, even if reading out the fault memory is relatively easy for a layman, both with and without a diagnostic device, a visit to a workshop is still necessary in some cases. Thus, the interpretation of error codes often requires the knowledge of an expert. Although it is possible to find corresponding descriptions on the Internet that are assigned to the individual codes, even then it is not always clear how the errors can be fixed or whether they are relevant problems at all.
In particular, if the stored code indicates a safety-relevant problem, the corresponding messages usually cannot be deleted via the methods presented without a diagnostic device, so that in these cases the help of a workshop is required anyway just for deleting the memory, which can then of course also investigate the indicated problems on the vehicle accordingly and, if necessary, rectify them.
Also, employees of an auto repair shop that has, for example, a Gutmann diagnostic device costing about 10,000 euros and thus absolutely unsuitable for non-professionals, can get help with more complicated defects from the manufacturer’s hotline. Trained specialists take care of the respective problem and then give the workshop well-founded feedback on the specified error and its repair.
In any case, you should refrain from deleting the read-out fault memory before visiting a workshop, unless you are completely sure that the stored messages have no relevance.