Operation CHARM: Car repair manuals for everyone.
Home >> Porsche >> 2004 >> Boxster (986) F6-2.7L >> Repair and Diagnosis >> Heating and Air Conditioning >> Testing and Inspection >> Component Tests and General Diagnostics >> Air Conditioning H02 >> Control Unit Function

Control Unit Function



Control Unit Function

Replacing The Air-Conditioning System Regulator And Flashing Display

NOTE: If the air-conditioning system regulator is replaced, the display flashes after the ignition is turned on. In this case, a system test must first be carried out. The air-conditioning system regulator then learns the drive motor limit stops and the entire system is checked at the same time.

System Test
Special diagnosis routines can be run with this menu item.

1. Using the Porsche System Tester II No. 9588, select the menu item 'System test'.

The following conditions must be observed for the system test:
- Vehicle speed < 10 km/h
- Engine start detected and 10 seconds elapsed since engine start
- Terminal 15 supply voltage OK
- Sensor supply voltage (5 V) OK
- Engine temperature < 110 degree C
- Outside temperature > 3 degree C
- No fault stored
- Engine idling

2. If the above conditions are satisfied, press the >> key to continue.

The following tests are performed:
- Display of all segments in the control unit.
- The drive motors are traversed across the entire range once.
- The measured positioning travel is subjected to a plausibility test.
- Two different voltage values are set on the fresh-air blower and tested.
- The A/C circuit is tested via the DME.
- All fault paths are tested, and any faults are stored.

3. On completion of system test, the following text appears 'System test successful. Display fault memory with >> key.'.
4. Press >> key and, if necessary, remedy fault displayed.

After the system test, the air conditioning system regulator reverts to the state it was in before the test.

Modifying Coding
Under this menu item, the coding of the following functions can be extracted and changed:







PROCEDURE:
1. Using the Porsche System Tester II No. 9588, select the menu item 'Modify coding'. (The table appears.)
2. The display can be saved using the F4 key.
3. Using the Up Arrow and Down Arrow keys, select the coding to be changed and continue with the >> key.
4. Using the Up Arrow and Down Arrow keys, select the correct coding and confirm with the 'Coding' key (F8) .
5. The display at the top right changes to the new coding.
6. To review the coding, go back using the << key.
7. Select another coding (see Step 3) or end the procedure with the << key.
pro multis · About Operation CHARM