Engine/Transmission (1998.5 - 2002) Charging system P0622 code

[HEYBOSS]

There's no check engine or gauge lights on.

While back comparing friend's truck data and codes on scanner, I found the P0622 code on the trans/ecm which means alternator field not switching.



Did a diagnostic check per diagnostic troubleshoot tree and all came up OK. Only thing I notice is the charge needle is one needle width over the 14v mark, and now with the cold weather is two needles width over. I put a volt meter on the Battery and it reads around 14. 4v



I wonder if anyone has this code and if their gauge reads the same?



TIA.

 

[Straight6Jeff]

Fred,



Howwya been? In the cold weather, the systems will read a little higher voltage... improved conductor conditions, less voltage drop thru the system. Electrical systems like cold, they function better. So the increased gause reading should not be a problem, as long as it doesn't peg to high (like 16v for prolonged periods)



As far as the codes, I wonder if it could have been related to when your heater grid relay leads were loose? that's a bunch of current to have a bad connection point. Also check your alternator leads. I found that mine was rubbing against something, I don't remember what it was now, but there was a little insulation missing from the lead wire. Tha's about all I hav eot offer right now, as I would just be talking out of my ring steak about anything else. Maybe the above originates from there also. I need a coffee

 

[HEYBOSS]

Doing good Jeff.



That's what I figured it reading a little higher on cold weather as this has the Batt. temp sensor.

I've replaced the grid heater solenoids when new due to loose connections and burnt the solenoids. I checked all battery, alternator connections and per diagnostic troubleshoot tree it all came up OK. I seem to think it could be a bad ecm just kicking up the code for no reason.



The code is a hard code, as soon I clear it, shut the key off and restart engine, it comes right back! Every thing seems fine and the only way I found the code was just fooling around with the scanner, other wise would never know it.



Fred.