Archived charging system problem

[mjlexus]

I just changed the alternator, and both batteries. I still have trouble codes P2502, P2509, P0622, what should I be looking at? The alternator is putting out 14. 06 volts.

 

[Missouri Mule]

Is everything up and running? Is the Voltmeter showing aprox 14 volts?



Did you erase the codes? Did the codes come back after erasing?



Year of Truck?



If your still having trouble with your truck then 2509 ECM/PCM Power input signal intermittent) could be your problem.



2502(charging system output voltage) with 14 volts you should be OK with that one.



622 (Generator field control circuit)?

 

[mjlexus]

The truck is a 2003 srw. Voltmeter says 14. 06. Vehicle is running, I will drive the vehicle today to see if I still get the 14 volts. Don't know how to erase codes other than disconnecting battery, which had to be done. If it is the ECM do I need to replace it? I did read the voltage regulator is in the ECM. Thanks Mike

 

[Missouri Mule]

Usually you need to have a scanner to clear codes.



I had thought if it was a 3rd gen it wouldn't have a PCM but I'm not sure when they dropped it.



With the batteries/alternator kicking out 14 + volts you should be OK just as long the check engine light isn't coming on.



In the 2nd generation and I would assume that the 3rd gen was the same there is a battery tempature sensor under the drivers side battery tray it sends tempature readings to the Electronic Voltage Regulator (EVR). The ASD relay sends line voltage readings to the EVR with these two inputs the EVR determines Alternator voltage output.

The tempature of the battery determines the voltage, with cold batteries the EVR cranks up the voltage with warm/hot batteres the voltage will be less.