So as I was traveling on the interstate, an unusual thing happened. All of the dummy lights suddenly lit up, all of my gauges went to zero, and an alarm began to sound (a beeping from the dash) Everything returned to normal soon after, but the check engine light came on and stayed on. It was later discovered that the passenger side knock sensor was snapped off. The problem is now solved, but I'm just curious if the unusual circumstance occurred when some object from the road struck and broke that sensor. Has anyone ever experienced something like this?

Something that impacts several different circuits at once usually has to do with a bad ground or a short. It could be that the knock sensor shorted and caused a reset condition in the computer or caused another circuit to short.

I am no expert on these however I do like to guess sometimes. :D Normally the all lights on and zeroing of the gauges occur when the power cycles resetting the dash. So my guess is that the object breaking the knock sensor caused enough of a short term short that the dash resetting the dash.Mike

"Dummy lights" HUH. Well they got your attention! :BSorry, couldn't resist! I would also go with the sensor shorting very quickly! Goofy things can and do happen. At least it didn't die on you!!!

I had a similar situation with my Dodge Caravan, though in my case it was a cell in the battery that was going bad. While starting in the low voltage condition all the gauges would go haywire. As soon as the engine started and the alternator began adding the proper amount of voltage to the system the engine control monitor (ECM) would reboot and all the instruments would work normally again. It was very disconcerting to say the least.

gearheads help me out with this please | Good Sam Community

wa8yxm
Explorer III
Jun 18, 2015
mabynack wrote:
Something that impacts several different circuits at once usually has to do with a bad ground or a short. It could be that the knock sensor shorted and caused a reset condition in the computer or caused another circuit to short.

That almost happened to my daughter one day on her way to school.

The first part (Lights on,gauges to zero,engine died) happened,, the came back on part did not.

Bad grounds.. New harness.. Thankfully I had insured that car for that.
ArchHoagland
Explorer
Jun 18, 2015
A bit more information on your motorhome would help. Those symptoms are common on one brand.
Peg_Leg
Explorer
Jun 18, 2015
I used to drive for a auto auction. I once had a Caddy that had a bad alternator and when the battery voltage got to 10.5 v. The tranny warning came 1st then everything avalanched from there very quickly to a complete shut down. Todays computer systems won't accept low voltage conditions.
outofplace
Explorer
Jun 18, 2015
We have had a couple vehicles that this is happened with and after each on the Alternator took a crap
dodge_guy
Explorer II
Jun 17, 2015
late bloomer wrote:
dodge guy wrote:
"Dummy lights" HUH. Well they got your attention! :B

You betcha! Along with the "poop your pants" alarm it definitely did.

I heard they can be loud. Especially when your not expecting it!
late_bloomer
Explorer
Jun 17, 2015
dodge guy wrote:
"Dummy lights" HUH. Well they got your attention! :B

You betcha! Along with the "poop your pants" alarm it definitely did.
Geocritter
Explorer
Jun 17, 2015
I had a similar situation with my Dodge Caravan, though in my case it was a cell in the battery that was going bad. While starting in the low voltage condition all the gauges would go haywire. As soon as the engine started and the alternator began adding the proper amount of voltage to the system the engine control monitor (ECM) would reboot and all the instruments would work normally again. It was very disconcerting to say the least.
dodge_guy
Explorer II
Jun 17, 2015
"Dummy lights" HUH. Well they got your attention! :B

Sorry, couldn't resist! I would also go with the sensor shorting very quickly! Goofy things can and do happen. At least it didn't die on you!!!
the_bear_II
Explorer
Jun 17, 2015
X-3 on short/reset
mlslcan
Explorer
Jun 17, 2015
I am no expert on these however I do like to guess sometimes. :D Normally the all lights on and zeroing of the gauges occur when the power cycles resetting the dash. So my guess is that the object breaking the knock sensor caused enough of a short term short that the dash resetting the dash.

Mike