Hood Open Warning - Except it isn't
 

Hi -
I've got a 2001 C240. The hood open warning just started coming on, but I had not opened the hood and it appears to be secure. I've open and closed it, according to the manual, and with some force, but the warning still comes on. Where are the sensors located? Any advice? I was just going to lubricate around the latches and sensor areas to see if it would take care of it.
Thanks!
WW

Did you install a CL-style grille recently? I got that too when I had that grille, but i opened and closed it and it was gone. :nix:

No - No mods - just came home with a load of groceries in the trunk and it started when i pulled into the driveway. 2001 with only 8K miles.

My 07 did that for about a month or 2 on and off. The sensor is located on the drivers side on the radiator support. Look for the hole that the hood catch goes into and the sensor is there.

Mystery solved. Facing the bonnet, there are left and right hood latches. The closed hood switch is on the left under the latch. It was being held in place by a plastic cage with snap-lock fasteners, and it had come loose and the whole assembly was hanging down out of view. I'm surprised it hadn't come loose sooner.
Thanks all for the replies!
WW

Mine started acting up again :rolleyes: The sensor is secure and plug is secure.

Boy, my car is really starting to wake up the electrical gremlins :(

Same with me.
Once i installed the CL style grille, you have to slowly pull it down and then slam it fast but gently to get it secured correctly. What an aftermarket flaw :P

The 'Hood Open' gremlin popped up on me after replacing the hood struts (shocks or whatever you want to call them). This is the first time I've ever seen this warning - the whole display turns red and can be cleared but comes back every time you stop. On my '03 c230 the sensor is located on the drivers side latch assembly. I pushed on the sensor where the wires go in and it seemed to snap back in place. All good now but crossing my fingers that that was all it took.

The sensor mounting tabs get weak or break off and the switch falls down. Usually have to replace the sensor itself once they get bad enough.

My 2003 C230 Coupe did this (and other miscellaneous electrical problems) and it turned out to be clogged drains in the wiper well that caused water to overflow into the fuse box. Cleared the blockage, dried everything out and problems solved.

Had this start happening me this week (07 W203 C180), immediately before it's yearly NCT so the fault immobilising the windscreen wipers was an issue! Gave the connection a clean with contact spray then used a cable tie to keep the metal down on the switch (after unsuccessfully just trying to bend the metal so it would work as previously to no affect). Worked to get me through the test but it's still coming up on the dash intermittently, I'm thinking it'd would just be worth ordering the part and switching out as seems relatively easy to change? Anyone have the part number to share?
wouldn't mind also seeing any pics from anyone else who's gone the cable tie method, I'm thinking maybe if I adjusted where the tie is it might sort it better.
(Had posted this in the E class forum first as seems it's common with them too

TL;DR- 2003 C32. Hood warning comes on intermittently, wet or dry, after car is thoroughly warmed up. I am positive it's not the switch, given said switch is currently disconnected and sitting on my desk.

As posted in C32 sub-forum...
https://mbworld.org/forums/c32-amg-c...sor-issue.html