Mercedes Repair Questions? Ask a Mechanic for Answers ASAP
Hi Earl, my name is***** are no fuses or relays for the hood switch circuit. The hood switch sends a ground signal to the rear signal acquisition module when the hood is closed. The blue wire at terminal C5 of the rear SAM needs to be checked for a ground signal. If there is a ground at the connector and the hood open warning continues to come on the problem will be either the connector to the rear SAM or a bad rear SAM. If there is no ground going to the rear SAM it would indicate a break in the wiring from the hood switch to the rear SAM.
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Just disconnect the plug at the rear SAM, close the hood and probe the blue wire with one lead of your ohmmeter and connect the other lead to ground. If the circuit is good you will read 0 ohms with the hood closed and OL or infinity with the hood open. If the circuit checks good you will need to replace the rear SAM.
The diagnostic chart may have it backwards. Try driving the car with the switch disconnected. If it still beeps try driving the car with the blue wire grounded. If it still beeps, and you are getting the signals all the way to the SAM, you will need to replace the rear SAM.
Hi, just following up with you on this question. Did you get this squared away yet?