low voltage

[jj_long81]

hello. check engine light does not work. i test at bulb. .93 volts when in diagnostic mode. selinoid is clicking. the same voltage is measured at diag connector and at computer brown wire .93 volts. why? still thinking my ecm is bad. i dont want to buy if im over looking somthing. ive checked all grounds. checked all fuses. i found a 30 amp fuse for my fan that had gotten hot and melted a bit but it did not blow. could this be related to my check engine light not working?

 

[Wajulia]

Sorry, but it sounds like the ECM is bad.

I included the trouble shooting chart for NO CHECK Engine LIGHT.
Good luck.

 

[Wajulia]

I also include a pinout of the computer connectors to help you in the troubleshooting

 

[jj_long81]

thank you. that is very helpful. ill go look now. my conclusion was a bad ecm too but i also read a thread here that somebody had a simallar problem and it was the prom not makeing contact at all prongs so after removing the plastic housing and inserting the prom the problem went away. ill try that too then ill break down and buy the new ecm. unless somebody else has any suggestions. thanks.

 

[Wajulia]

If the ECM is operation and the PROM is in wrong, there will be a code that the PROM is wrong (51 if memory serves me right) Check engine light will still work properly

Good luck

 

[VetteV8]

i found a 30 amp fuse for my fan that had gotten hot and melted a bit but it did not blow. could this be related to my check engine light not working?

If the fuse is melting and/or the fitting has done the same thing, then this is an indication of too much resistance, so likely dirty contacts; also the fuse may be the problem, as these are mostly from aluminum, and these get surface corrosion too.
To get rid of the problem: clean contact surfaces, and the fuse too.

Clearly, this has nothing to do with your Check light.
Cor

 

[maxmachz]

Check the big plug that goes into the printed circuit on the gauge cluster. Also check the printed circuit sheet as well.