Test 14: Lock Signal From Driver Door Switch
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 1999 Mercedes-Benz E430, 1999 Mercedes-Benz E320, 1999 Mercedes-Benz E300, 1999 Mercedes-Benz CLK430, and 1999 Mercedes-Benz CLK320. However, it is still accessible from the selected car via links, so may be relevant.
Connect Hand-Held Tester (HHT) to Data Link Connector (DLC) located in engine bay. Monitor door control module readings. Use key to mechanically lock vehicle and hold key in lock position. If YES is displayed on HHT, system is okay. If NO is displayed on HHT, perform TEST 22: DRIVER SIDE DOOR CONTROL MODULE VOLTAGE SUPPLY TO LEFT FRONT DOOR LOCK SWITCH and TEST 23: LEFT FRONT DOOR LOCK SWITCH under SYSTEM TESTS.