Power Diagnosis

Waking up the vehicle
Registration of the waking in the JBE
As of model year 03/2007 for the 1 Series and 3 Series, the K-CAN wakings can be detected by the JBE2 and allocated to the individual control modules. The last 50 CAN messages that woke the K-CAN bus are saved in the energy history memory in the JBE. The relative time from the instrument cluster and the kilometer reading are also saved as marginal conditions.

However, no distinction can be made between authorized and unauthorized wakings.

Note:
If the test module is unable to interpret the waking CAN message, "unknown control module" is displayed as waking. This can have the following possible causes:
- JBE was unable to recognize the waking CAN message properly.
- The saved CAN message cannot be allocated to any control module.

Brief description of components
Waking registration in the junction box electronics
The JBE contains another processor, a so-called co-processor. As the JBE itself 'goes to sleep in the idle state, thus switching off the main process, the JBE would not notice a brief waking.
With the other processor, the K-CAN bus can be permanently monitored and the waking attempts saved in the energy history memory.

System functions
The wakings are recorded in the time span between terminal "R off" and terminal "R on". Due to the electrical processes in the idle state of the vehicle, wakings also occur when the vehicle is fully intact. This means that when these wakings are evaluated the wakings that normally occur are to be taken into account:

Authorized waking






Recording wakings

Normal (A) Vs Failure (B):

Difference between normal case A and failure frequent waking B (see illustration above).
1. Terminal R OFF
2. Waking FRM (8 minutes after terminal R Off): Consumer shutdown only if the vehicle is not locked.
3. Waking instrument cluster (KOMBI) (40 minutes after terminal R Off): Query of the coolant temperature. Waking does not always occur, only under certain conditions.
4. Waking instrument cluster (KOMBI) (80 minutes after terminal R Off): Query of the coolant temperature. Waking does not always occur, only under certain conditions.
5. Authorized wakings: see table above.

Notes for Service department
General information
Troubleshooting in the event of a problem with too many unauthorized wakings
The vehicle is not permitted to wake any of the control modules not mentioned above. In the event of faults in the energy diagnosis test module or in the service function for analysis of the waking, they are recognized as unauthorized wakings.

In the event of faults (frequent unauthorized waking), the following possible causes are to be checked:
- Defective peripherals of the cause (for example defective sensor or switch).
- Defective control module.
- Wake-up cable for causes or CAS connected to the PT-CAN (for example, loose contact).
Diagnosis instructions
Observe the instructions in the diagnosis system: Test module energy diagnosis, service function for analysis of the wakings and possible fault memory entries of the cause.