What does "CO" mean on a digital fuel gauge?

September 29, 2014, 09:18:54 PM

The readout on my digital cluster for the remaining gallons of fuel has started reading "CO" all the time. I've never seen that before. Anyone know what it means?

What does "CO" mean on a digital fuel gauge?

Reply #1 – September 30, 2014, 04:59:25 AM

Circuit Open. Bad sender or a problem in the circuit.

What does "CO" mean on a digital fuel gauge?

Reply #2 – September 30, 2014, 09:40:58 AM

The shop manuals have a detailed list of alpha-numeric codes but Foe must have found it already or else I would have looked it up.

From my diy link below in my signature, there resides the following information.

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Troubleshooting the Digital Speedo
Hold the Trip Reset button in
turn the ign switch to run
advance through the tests by pressing trip reset
a steady tone and a "P" on the display says it passed.
example
first display will have
54 in upper left and step number 1 in upper right, P in the center
here are the displays for a passing speedo

54 1 P
78 2 P
E4 3 P or F
nothing 4 P or F
nothing 5 P or F
nothing 6 P or F
nothing 7 P or F
1p 8 P or F

display test prove out is step 9
=========================
Tach/Multi guage diagnostic

all codes are Hexadecimal format and can range from 00 to FF (binary 0000 to 11111111)or (decimal 0 - 128) . While active in the various modes, they can be used as a "wiggle test" to check for shorts and intermittant circuits. Anyway,, display will be in hex format.

hold the guages button in and turn the ign key to RUN
Advance through the tests by pressing the guages button.
A steady Tone and 8 bars lit is a passing test
No tone with 24 bars lit is a fail

To enter the Fuel computer self test
Press and hold the Select button atleast 5 or so seconds until the test display appears then advance thru the tests by pressing on Select over again.

The shop manuals have a detailed list of alpha-numeric codes but Foe must have found it already

What does "CO" mean on a digital fuel gauge?

Reply #3 – October 16, 2014, 03:56:34 PM

Thanks for the info. I took a quick peek under the car and saw the problem right away. The car has been sitting outside again for several months and something chewed through the wires. I'm just glad I won't have to drop the tank to fix it.