Voltage at ALDL not reading new tool from fiero store (Page 1/1) Superm1952 OCT 12, 04:09 PM ALDL questions. Recently purchased ALDL reader from fiero store. Two fieros both 1986 v6 GT's.... #1 fiero the tool works as it should. #2 fiero Not a thing. This is what I have done on #2 so far: All fuses are good. Battery is fully charged. I tested the good fiero at the ALDL for voltage it fluctuates between 3.26 and 4.2 it does not hold a solid voltage but tool works fine. #2 fiero reads a solid 5.01 yet nothing. Where am I at with this. #2 fiero has a replica dash so no chk engine light. At this point I have reached the end of my knowledge as to where I should be at this point. I hope someone can give me a direction as to where to start or how to continue. Very frustrated. The other fiero (replica) knocks it right out but this recently acquired #2 has got me very frustrated. Thanks in advance. Skip Fl. phonedawgz OCT 20, 04:33 PM First thing I would do is swap ECMs and see if the trouble is in the ECM. If all you are doing is scanning it won't make any difference. An AT ECM is different than a 4 speed or 5 speed manual. The only difference between the 4 speed and 5 speed ecms is the shift light. But the short of it is you can swap them and see if one of your ECMs is bad. Next - On the ALDL connector - Pin A is ground, and pin B is the trigger pin. If B is grounded the ECM goes into a mode that flashes the check engine light. If there is a 10K resistor between pin B and ground, the ECM spits out data at a rate of one packet every 1.25 seconds. The tool reads that data. So the only thing that makes the data spit is the 10K reistor. You could try putting a 10K resistor from A to B and see if the data starts spitting out. You could also look at the Pin B wiring. On a V6 Fiero pin B of the ALDL connector runs to the ECM via a White/Black wire and terminates at the ECM on pin A9 in Connector C2. You should be able to verify this wire with an ohm meter. I would not expect it to be bad. Hit me up on Facebook if you have more questions - Timm Bacher - The one in titletown, not the one in Germany. There are only two of us in the world.