Toyota Nation Forum banner

Camry alternator

1K views 6 replies 4 participants last post by  okpara 
#1 ·
Hello all I am new to this forum, and I would really appreciate if some one can enlighten me some more on the different functions of the pin terminals on my alternator. I have a Camry 09 2.4L with an OEM alt ( 27060-0T041 ). I am just looking for further information on what does pin terminal IG, L, S, M is responsible for and what symptom/symptoms that occur when any one of these terminals breaks connectivity to the alt. For instance what happens when M terminal loses connectivity to the alt. Thanks in advance
 
#2 · (Edited)
IG, L, S, M...

Let's see

IG, is conencted to your ignition switch and energizes your coils
L, makes the 'low charge' warning light go off on the dash
S, 'senses' the actual battery voltage
M, reports the raw, unregulated output of the alternator.. think of it as a 'bypass to the alternators regulator'

If IG fails your coils wont energize and the alt wont make power
If L fails your wanrning light on the dash won't come on, or it will be on all the time depending on the design
If S fails you may either overcharge or undercharge as the true battery voltage will be mis-read.. in some designs the alternator may not charge at all if S fails
If M fails it will either throw a CEL for P2503 (low charge/voltage) and/or throw the 'low charge' light in the dash...

Think of M as a more refined version of L to warn you when teh alternator is on the fritz. Typically L would only warn you after your alternator was well dead and you'd be stranded with no juice to get home. M on the other hand is hooked up to the ECU which constantly monitors the output of the alternator (BEFORE regulation... ie raw, maximum UNREGULATED output)... if it gets below as set paramater the CEL fires to warn you AHEAD OF TIME that your alternator is about to crap the bed... presumable preventing you from being stranded...


///
 
#5 ·
Camry alternates are prone to failure, my '07 went and then my '06 went in almost complete meltdown. Certain years have a special clutch on the pulley so if you have to replace it be aware.
 
#7 ·
Hey @ Blackness,

I have one more question, as you stated the " M" terminal is a refined warning indicator of the ALT state, my question is if there is a break in connectivity from the M terminal to the ECM, does the alt perform to it's full capacity or does the ECM also play a role in controlling charge rate.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top