Check Guages light

[joel]

The last couple of weeks, my Check Guages light has stayed on longer than the 2 second self test cycle. All the guages come up to normal - well, the temp guage is pinned left since the engine's cold - and everything sounds normal. A couple of times I've shut down and cycled the key 3 times to see if I get any codes but I don't. Hmmm, stupid question, but do you have to be in ODO to get the codes? I usually run around in the trip mode of the odometer.



Anyway, anyone have any thoughts or suggestions?

 

[Mark_Kendrick]

Check the voltmeter. When My truck was new I had problems w/the alternator and it worked intermittently.



You alternator may not be charging well at low rpm.



then again I could be wrong

 

[joel]

Alternator shows what it always has

around 10 or so with the heaters on and a little over 14 with them off.



Hmmmm... .....

 

[Challenger-II]

I noticed that my '99 does the same thing from time to time... . never any problems though. It's probably normal.

 

[Alan Reagan]

Joel, On cold mornings, when the grid heaters are cycling, it sometimes takes longer for the lights to go out. The computer is taking inputs and the pull down of the voltage by the heaters drawing so much current is probably causing the computer to cycle through it's comparison's a few more times to make sure all is OK.

 

[mongoose]

my 99 is the same way. this winter, if i did not plug in, the grid heaters would pull the voltage down below the first mark. I would notice the check gauges light to stay of until the voltage come up to the first mark. I'm thinking it's going to be new battery time before next winter!

 

[Alan Reagan]

The firmware that does the checks has a certain fault tolerance to avoid setting faults until it is determined there is truly a fault. If you were driving down the road with the engine warmed up and the voltage dropped to 10 volts and continued to fall, a fault would be set. Once it is determined that the situation is not correcting itself, the code will be set in memory.

 

[Mark_Kendrick]

I'm glad to see that I wasn't totally off base. Weak batteries on a cold mornig would cause this. The grids pull mine down to 11-12v on a regular basis. It must not be low enough to cause a light.