PeachParts Mercedes-Benz Forum - View Single Post - No check engine light when O2 sensor Disconnected. Bulb OK

ps2cho · #4 10-29-2010, 03:34 AM

M.B. Doc -- You are right on the money. After about 15minutes driving I saw the light come on.

OK -- so I have established the ECU recognizes the O2 sensor, now going back to the test procedure: Do you put the DMM inline between the two wires or do you need to measure it using an alligator clip and ground the other side of the DMM? Which is the correct way? I want to double check my basic tests before going further.

0.48v stuck is what it is reading. I want to make sure that is correct and then we can talk about why from there.