2004 chevy silverado, check engine LED not working

[borshch]

2004 chevy silverado, MIL check engine LED is not working.
(my GM MDI is still not working,) so will need to test it by applying voltage to pin 1 and GND?
how much Voltage should I apply to that LED to test it ?

[Speedoman57]

I have always done 2.5 to 3v

[dllas]

I think a GM MDI is too new for testing these. You want a GM Tech2 amd it supports gauge sweeps and light tests.

[borshch]

I think a GM MDI is too new for testing these. You want a GM Tech2 amd it supports gauge sweeps and light tests.

“GM MDI” is just and interface, but “tech2win” is software

I have tech2win with ALLSCANNER vcx nano interface (my GM mdi interface died),

but there’s no option to test MIL light in tech2win.

[clusters]

To illuminate the MIL, power up the cluster and with a test light attached to ground, touch it to Pin A1. The PCM grounds the MIL circuit to activate the light, but a test light is safer than a jumper. :)

There is an option in Tech2win to test the MIL, but it illuminates all the warning lights. In the active test menu choose lamp test.