Work Instructions After Disconnecting the Battery

Work Instructions After Disconnecting The Battery

Effect of disconnection or total discharge of the battery on electrical systems in the vehicle, subsequent measures

INFORMATION:
- In order to avoid triggering the alarm siren (installed on right next to the battery) of vehicles with M 536, the battery must be disconnected with the ignition on.
- All loads must be switched off beforehand.
- Never disconnect battery with engine running.
- Never start engine without securely connected battery.
Do not use a boost charger to start the engine.
- Whenever possible, use jump leads with overvoltage protection.
- Always disconnect both battery terminals before carrying out welding work on the vehicle.
- Wiring harness plugs of control modules or other electronic components must be connected or disconnected with the ignition off. Exception: vehicles with the additional equipment M 536 (alarm siren with tilt sensor).

Control module memories

Problem Remedy
Values and faults stored in the control If possible, all fault memories should
modules can be deleted if the battery be checked and, if necessary, printed
is disconnected or completely discharged. out before the battery is disconnected.

Supply voltage fault entry

Problem Remedy
The entry "supply voltage" could Delete the "supply voltage" entry from
be stored in various control modules the control modules in question.
if the battery has been completely
discharged.

Test drive after connecting the battery

INFORMATION: The fault memories of all vehicle control modules should be read out again after the test drive.

2470 DME control module

INFORMATION: With all DME systems, the engine must run for several minutes before the engine control module can relearn the idle speed and mixture adaptation values.

Problem Remedy
- After disconnection of the power After the battery is connected.
supply, the idle speed might change With the DME ME 7.8, it is necessary
or fluctuate briefly until the throttle to carry out a learning and adaptation
adjusting unit (ME 7.8) is readapted. routine as described below:

- The mixture adaptation is also lost. Switch the ignition on for 1 minute without starting the engine. Do not actuate accelerator pedal.

Switch off ignition for at least 10 seconds.

This completes the adaptation of the throttle adjusting unit.

6452 Power windows

Problem Remedy
The limit positions of the power windows Manually close each power window as
are deleted from the control module when far as it will go, then press the rocker
the battery is disconnected and connected. switch for closing the window again.

The limit position of the respective power window is now stored in the control module again.

90 25 Instrument cluster
The trip counter is set to 0 when the power supply is disconnected.

9030 Clock

INFORMATION: In the case of vehicles with PCM, the date and time are deleted when the battery is disconnected.

Problem Remedy
The time is deleted when the power Enter the current time again.
supply is disconnected.

9023 Fuel level display

Problem Remedy
- If the power supply is Fill the tank; then the fuel level
interrupted by a discharged or sensor is in operating range and
disconnected battery with the its display precision is guaranteed.
tank containing less than 19 l,
the calculated value for the
range on remaining fuel in the
instrument cluster will be
incorrect or deleted.
- If the tank contains less
than 19 l, it is possible that the
fuel level warning light is no longer
activated.
- If the power supply is restored
with the fuel level at less than 19 l,
it is possible that the fuel level
display may subsequently display an
incorrect value.

This may lead to the vehicle breaking down.

9120 Radio

Problem Remedy
The radio reverts to the Code Input the radio code.
function when the battery is
disconnected and is thus no If the code card is unavailable, the
longer ready for operation. radio code can also be read from the DME control module (under "Vehicle data").

It is also possible to gain this code from the Porsche IPAS.

9110 PCM

Problem Remedy
- The PCM reverts to the Input the PCM code. If the code card is
Code input function when the unavailable, the PCM code can also be
battery is disconnected and is read from the DME control module (under
thus no longer ready for operation. "Vehicle data").

- When the power supply is It is also possible to gain this code from
disconnected, the built-in GPS the Porsche IPAS.
receiver loses the so-called
almanac containing the satellite
orbital paths.

- The date and time are Switch on the PCM with a free panoramic
deleted when the battery is view for approx. 20 minutes (to load
disconnected. GPS almanac).

- Radio stations stored by The date and time are also adopted once
the customer are no longer displayed. the GPS almanac has been loaded; it may be necessary to change over to summer time (daylight-saving time).

- If the telephone card was This time is transferred to the instrument
inserted and the telephone was cluster. If the time then manually
ready for operation, the changed by means of the instrument
telephone is subsequently disabled. cluster, this time is adopted by the PCM and synchronised with GPS time.

The stored stations are displayed again when station buttons 1 to 6 are pressed.

The telephone is enabled again when the telephone PIN code is entered with the SIM telephone card inserted.