Control Assembly: Service and Repair

A/C Control Head -E87-, Removing And Installing

The A/C control heads are coordinated differently, the allocation must be observed when replacing the A/C control head and observe notes as well.


NOTE: In the period from week 36 to week 44, 1998, there was a running change in production from version 1 air conditioner to version 2 air conditioner. The two versions can be differentiated by specific characteristics .


- In vehicles with air conditioning unit "1" only A/C control heads with part number and including index "G" can be installed.
- In vehicles with air conditioning unit "2" only A/C control heads with part number from index "H" can be installed.

- Vehicles with 8 cylinder engines are only equipped with air conditioning unit version "2".
- Starting with model year 2002, A/C Control Heads -E87- are installed that communicate with other control modules via the CAN-bus system
- Check DTC memory before removing A/C Control Head -E87-.
- After replacing A/C Control Head -E87- always:
- Check or enter new coding.
- Carry out basic setting.
- Check DTC memory.

- The display panel on A/C Control Head -E87- changed from °C to °F and back by pressing and holding the "Recirculate air" button, then pressing the temperature "+" button for the driver's side.
- If A/C Control Head -E87- remains on after the ignition has been switched off, test for short circuit to B+ in the wiring to terminal 1 of connector -D- (connection for auxillary heater) using wiring diagram.
- If a new control head is installed and its display panel flashes (for about 2 minutes) when the ignition is switched on, code the A/C control head and carry out basic setting.
- If the two display panels do not light up when the ignition is switched on, restore voltage supply to terminal 58d (dimming) for -E87- according to wiring diagram (Read Measuring Value Block "function 08") and (electrical testing).

Removing and installing
- Vehicles without Radio-Navigation system
- Remove radio.
- Remove center trim section of instrument panel.







- Remove bolts -A-.


NOTE: After removing the two lower screws -A-, the clips located in front of the fastening straps on A/C Control Head -E87- should be tipped forward and removed using a screwdriver.


- Remove A/C control head -B-.

- Vehicles with Radio-Navigation system
- Remove Radio-Navigation system.







- Remove bolts -A-.
- Lift A/C control head -B- up slightly and remove in direction of arrow.


NOTE: In these vehicles, A/C control head is held underneath by latching tabs -C- and -D-.


- All models







- Press back harness connector release catches -F- and disconnect harness connectors -A- through -D-.
- Press back harness connector releases catches -G- and disconnect harness connector -E- (for rear window heating).


NOTE:
- The display panel and control buttons are illuminated with LEDs (which cannot be replaced).







- Different versions of A/C Control Head -E87- are available as replacement parts depending on vehicle equipment (for example, with or without openings for heated seat switches).
- To remove heated seat switch, press back retainer tabs -A- and pull switch -B- out of A/C Control Head -E87- from behind.
- If Instrument Panel Interior Temperature Sensor -G56- is giving an incorrect reading, make sure intake grill on panel is not obstructed.