Mercedes-Benz Tech Tip: A/C Compressor Clutch Won’t Engage – UnderhoodService

Mercedes-Benz Tech Tip: A/C Compressor Clutch Won’t Engage

Some owners of 1997 Mercedes-Benz E320 3.2L vehicles may complain that the EC light on the climate control push-button panel is continuously lit. This light is on because the A/C compressor clutch won’t engage. To correct this problem, refer to the following service procedure.

Problem:
A/C compressor clutch doesn’t engage; EC light on the climate control push-button panel is continuously lit.

Affected Vehicle: 1997 Mercedes-Benz E320 3.2L.

Service Procedure:
1. Read and clear DTCs in the A/C control module using a push-button on-board procedure. Turn the key to the ignition “ON” position.

2. Set the left temperature selector on “HI” and the right temperature selector on “LO.”

3. Within 10 seconds, press and hold the “REST” and “EC” buttons simultaneously for six seconds, then release.

4. The Light Emitting Diode (LED) in the recirculation button should begin to blink. The display should read “di A.”

5. Press the right “Auto” button to display DTCs. Keep scrolling through the list by pressing the right “Auto” button until the display shows “E FF.”

6. To erase DTCs, press and hold both “Auto” buttons simultaneously for three seconds and release. The display should show “D FF.” Switch off the ignition.

7. Restart the engine. If the “EC” button lamp is illuminated, press and release the “EC” button. The lamp should go out. If not, recheck for DTCs Key On Engine Off (KOEO), then recheck compressor operation.

Courtesy of IDENTIFIX.

For additional information, visit www.identifix.com.

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