anyone know what Generator L-Terminal Circuit ECM, PCM means? I just installed 60 lb injectors and 2.8 pulley got this code car runs good

 

hmm any stuttering when you accelerate slowly?

 

Here's what GM says:


If your needing any of the links from this, just holla. Most still point to GMDealerworld.com and prob wont work for ya.
http://fr33k.5gbfree.com/P0621.htm

fr33k

 

sounds like your alternator is overcharging slightly. Possible due to the smaller s/c pulley. Not a big issue

 

agreed^

 

interesting that we havent seen this before considering how many people run 2.8s and smaller.

 

It wouldn't be the alternator overcharging would it? The trouble tree says this code is for the turn on/off of the voltage regulator is incorrect.

"The ECM/PCM monitors the state of the generator turn ON signal circuit. With the engine running, the ECM/PCM should detect a high generator turn ON signal circuit, or when the charging system malfunctions. If the ECM/PCM detects a low generator turn ON signal circuit, DTC P0621 will set."

Probe your red wire on your alternator connector with it disconnected and with the engine running and see if you have 4.5-5.5volts goin to it.

 

Unless your "Battery Charge" warning lamp is ON (small pic of battery) or there's a CHARGING SYSTEM FAULT message on the DTC - you can safely just ignore this DTC. (for now at least just clear it and see if it returns)
It sets sometimes when you disconnect the battery, or disconnecting certain harnesses under particular power moding conditions.

PS> Changing your supercharger pulley DOES NOT change the pulley ratio to the alternator...
Wop