Toyota Repair: efi computer, faulty computer, computer side

Question
Dear Ted,  Thanks for your speedy response to my EFI computer question yesterday.  Check light only flashes once (repeating after several seconds)  when the T and E1 terminals connected and ignition on.  This is the code for normal operation. Does this point to a faulty computer?  Computer ground points show only 1, 10, 14 and 15 mV voltage drop, less than Alldata's recommended maximum of 30 mV

Answer
If the light flashes continouly twice per second with no pauses in between it is normal. Less voltage drop is better so that's not the problem.
It's possible that the computer itself is causing the problem, check all the connections for any corrosion on either the computer side or the connectors, there is no way to test the computer so it is replaced after eliminating all other possibilities that can cause the problem, this can be time consuming, the computer will only trigger a check engine light if it sees a faulty input signal from one of the sensors on the engine, it compares the input signal to it's built in logic and if the signal exceeds the parameters the check engine light comes on but if the computer has a problem and doesn't recognize a failure it won't store a trouble code.