Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
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Is this the ECM B fuse?
Okay the most common cause for the ECM B fuse to blow is in most cases caused by excessive amp draw from a failing fuel pump . In order to determine if in fact that is the cases you are going to need to do some testing while the problem is present. I have enclosed the steps to do this in the link below.https://dl.dropboxusercontent.com/u/104923897/ECM%20fuse%20B%20Nov%2026.pdf
Let check the fuel pump first as its a very common cause for this fuse to blow.
If you dealing with the ECM B fuse then the HO2S sensors are not on that circuit. Are you sure its the ECM B fuse?
The HO2S sensors use the ECM one fuse and if thats the fuse that blowing and stops blowing when you disconnect the bank one HO2S sensor then that would point towards a failing HO2S sensor. Need to know for sure which fuse is blowing.
Yes the ECM B fuse is the 20 amp fuse, one other thing on that circuit that could be shorting could be the orange power feed wire to the ECM (computer). That being said, the most common cause for this fuse to blow is a failing fuel pump or the wiring to it.
That I am not sure of but if you have the right fuse and it holds with the HO2S unplugged then perhaps is affecting the ECM and causing the fuse to blow. If its hold with this sensor unplugged then that points to a shorted HO2S. Did you try replacing it and see if the fuse still holds?
Have a look at the enclosed wiring diagram for the ECM B fuse, you will see the only things on that circuit is the ECM, fuel pump and transmission control module. The O2 sensor is not on this circuit.https://dl.dropboxusercontent.com/u/104923897/ECM%20B%20wiring%20Nov%2026.pdf
Okay can you get it into closed loop and pull the fuel pump relay and see if the fuse holds?
No it will not but if the fuse holds then that points to a failing fuel pump and or the power feed to it. If the fuse blows with the relay out then I would have a look at the orange power feed from the fuse to the pin 57 at the computer.
Well it has to be something on that circuit. Its just a matter of narrowing it down.
Okay I will open the post back up for you, perhaps someone else has something new to add.
Hi, My name is ***** ***** for the delay.
I will do my best to assist you.
it always blows the same ecm fuse?
it does sound as if you have a bnad fuel pump,,the pump is pulling too many amps,perhaps the pump motor is just bad..
if you have just replaced the pump it should be under warranty..
replace that pump with another one
the pump is getting hot and pulling too manyamps when hot,that is why it will run for a while after you replace the fuse
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Hi My name is***** see you got a lot of free pizza. Thank you for your service. I hope you get this resolved.