Instant/Average MPG computer stopped working!

[spyysee]

This is a strange one. My fuel rate stopped working. I really dont Know when that happened.
I recently replaced my fuel pump, but the guage seems to work.
Where is that data coming from?
Any Ideas?

 

[Ken]

The Helm Electrical Diagnosis manual states only that if the fuel mileage/instant fuel rate function doesn't work, to check the reset switch, and if that doesn't work to perform the following test:

FUNCTION SELECT SWITCH TEST

1. Disconnect the Telltale Assembly connector from the Instrument Cluster. Locate the wire terminal of the function that does not operate properly and measure the resistance between that terminal and terminal B1 (BLK) with the Switch being tested in the OFF position.

* If the resistance is infinite ohms, go to step 2.

* If the resistance is zero ohms, replace the faulty Switch or the entire Telltale Assembly.
​

2. With the ohmmeter still connected between the suspect terminal and terminal B1 (BLK), hold the suspect switch in the position to select the desired function.

* If the resistance is infinite ohms, replace the faulty switch or the entire Telltale Assembly.
* If the resistance is zero ohms, replace the Instrument Cluster.

​

Good luck.

 

[spyysee]

It's fixed!!??!
I went back to the fuel pump connections, cleaned the connector and monkeyed with a rusted ground.
It started to work again. hmmmmm. Sounds too easy, but I'll accept it.
Goes to show just how finicky the 'Vette is with electrical grounds.

 

[Mad-Mic]

that has happened on mine before. just disconnect the batter for 2 mins and let it reset and should be good to go. but this doesn't count cause you already fixed it and it was a bad ground