2003 Olds Alero 2.2 Alternator

[348tripower]

Anybody know if the output voltage is computer controlled? I can't find the answer.
Thanks and Happy New Year,
Don

[rooster]

Appears to be PCM controled! The auto zone web site has alot of diagrams for that car!

Whats wrong with it?

http://www.autozone.com/autozone/repairinfo/repairguide/repairGuideContent.jsp?pageId=0996b43f8036e73c

[wayne petty]

the V6 aleros use a CS130D style of alternator.


reading...  

this can be read online.. or there is a link to download a PDF file there

http://www.motor.com/article.asp?article_ID=1606

Are You Smarter Than a 'Smart' Charging System is the article


and this tidbit of info to explain some theory..

Tech Tip: Two Main Types of Voltage Regulators
There are two different types of voltage regulators used in automobile alternators. "A" type, "B" type.

"A" Circuit Type Voltage Regulators
These send full (positive) power to one brush, while the voltage regulator controls the output by varying the ground (negative) to the other brush. It does not matter which wire in the regulator field you power and which one you ground, as you can swap them around with no trouble. Early GM internally regulated alternators, such as the 10Si Series Alternator, used the "A" circuit type voltage regulator. Later Ford units, such as the 3G, 4G, and 6G also use "A" circuit type voltage regulators.


"B" Circuit Type Voltage Regulators
This second type of regulator sends ground to one brush inside the alternator. Then the voltage regulator controls the positive power to the other brush, which connects to the rotor coil inside the alternator. Controlling the positive power into the rotor coil allows you to turn the alternator on and off. Ford used "B" circuit type voltage regulators in early Motorcraft externally regulated 1G alternators and GM used them with the Delco type CS130 and CS144 series alternators.




cliped from the end of the article just in case it vanishes
its important to read the entire article from the site..


Regulated Voltage Control Explained

Regulated Voltage Control uses information from the battery current sensor, calculated battery temperature and system voltage to determine what the perfect voltage to supply the battery with is. In addition to nurturing the battery into longer life by maintaining proper state of charge, RVC allows the charging voltage to drop below the 13.8 to 14.8 volts to which we're all accustomed. If the battery can maintain an 80% SOC with 13 volts at a particular temperature, why would we want to charge it at 14.8 volts? Higher voltage comes at a price of increased drive belt load. Every bit counts with today's fuel economy goals. Additionally, light bulb life is increased with a slightly lower charge voltage. Depending on the model and year, the newer GM RVC charging systems may include up to nine different charging rates strategies, among them:

Battery Sulfation Mode. No sense hammering a battery that has given up the ghost!

Start-Up Mode. Gets the battery back up to greater than an 80% SOC quicker.

Fuel Economy Mode. Alternators that put out less voltage help engines use less fuel.

Headlamp Mode. Okay, it's time for a little more voltage now that the lights are on.

Referring to the RVC graph in Fig. 2 on page 44, you can see how much thought has gone into tailoring the alternator's charge output to suit various scenarios. An interesting sidebar note would be the ramp-up in field current that the RVC systems sometimes introduce on deceleration. When you're cruising in Fuel Economy Mode (lower charge voltage), you can charge harder during a brief period of deceleration without sacrificing fuel economy or overcharging the battery. In fact, when there's a greater alternator load on the engine during deceleration, that load contributes to engine braking—something that's good for brake pad life as well. Think of this as a mild form of what hybrid vehicles do with regenerative braking.

Speaking of hybrid vehicles, DC-to-DC converters (high voltage in, conventional 14 volts out) come online whenever hybrid systems are powered up. This may occur with the key on and the engine off. The DC-to-DC converter receives serial bus messages from a BCM or PCM on the vehicle responsible for the equivalent of RVC functions. This allows a hybrid vehicle's DC-to-DC converter to tailor a perfect charge rate into the vehicle's 12-volt battery.
RVC Operation & Diagnostics

To be clear, GM's RVC systems use alternators with field currents that truly are controlled by logic external to the alternator. You'll see two things right off the bat on RVC vehicles tipping you to the presence of this latest technology: First, you'll see a two-wire voltage regulator connection instead of the familiar four-wire connection. Second, you'll notice a funny-looking sensor or module wrapped around either the negative or positive battery cable. It may remind you of an inductive current probe, because that's what it is.

There are two types of these systems—stand-alone RVC (SARVC) and RVC. The former was used for a few years (mid-2000s) on light-duty trucks and SUVs. The current sensor in the SARVC system is built into a full-fledged electronic module complete with a Class 2 serial bus circuit to receive and transmit information. You probably won't find the data PIDs for this system in the PCM. The SARVC module is also known as a generator battery control module (GBCM) and is located within a list of body modules on the scan tool. Not all aftermarket scan tools can read this module, but they will display PIDs like Battery Voltage, Battery State of Charge, Regulated Voltage Control Current and Generator L Terminal Signal as a percentage.

The RVC systems use a Hall effect type current sensor that sends a PWM signal at 128Hz to the BCM. This sensor stays powered up long after the ignition switch is turned off. The reason is that this sensor also reports to the BCM any news of excessive parasitic current draw. This is also a scan tool PID—nice to know when diagnosing a battery rundown problem on a RVC-equipped GM vehicle. And speaking of PIDs, since the BCM is the module in charge of logic for this system, you'll find up to 20 PIDs under a heading titled Charging Info when searching for charging system PIDs within the BCM. Although the BCM is the "brains" for the non-stand-alone RVC system, it's the PCM that actually carries out the commands to control the L terminal with a PWM output to control the alternator's charge rate. To find output PIDs, go into the Powertrain section on your scan tool. You may encounter output PIDs in the section of the PCM titled Electrical/Theft. As with earlier non-RVC, four-terminal CS series alternators, the L terminal can be commanded on and off by going into the PCM and selecting output control.

On RVC vehicles, you'll see the charge voltage fluctuate while driving or even while running the engine in the bay. The changes will be subtle, as the rate of change varies from 10 to 20mV per minute. Charging rates as high as 15 volts are observable on some vehicles, depending on current demand and battery SOC, along with values as low as 12.9 volts. The PWM signal from the PCM to the L terminal on these two-wire regulators varies from 10% to 90%, with the latter being the higher voltage command (15.5 volts). If this circuit goes open, the default charge rate from the alternator is 13.8 volts.

One way to outsmart the smart charging system is to disconnect the current sensor or SARVC module. On some systems you'll see 15.5 volts with the engine running and a light electrical load applied. This should tell you if you're dealing with a good, old-fashioned alternator problem or a vehicle wiring or module problem. Naturally, DTCs will be set that will have to be cleared. Don't forget to look in the Body Controls section of your scan tool when clearing codes, in addition to the PCM.

But no matter how complex these systems seem, it all really comes down to a battery, an alternator and some modules monitoring and controlling voltage regulation. By knowing how these new systems work, you can keep outsmarting the latest smart charging systems that show up in your bays!

[348tripower]

Appears to be PCM controled! The auto zone web site has alot of diagrams for that car!

Whats wrong with it?

http://www.autozone.com/autozone/repairinfo/repairguide/repairGuideContent.jsp?pageId=0996b43f8036e73c

Intermittent charging

[rooster]

Appears to be PCM controled! The auto zone web site has alot of diagrams for that car!

Whats wrong with it?

http://www.autozone.com/autozone/repairinfo/repairguide/repairGuideContent.jsp?pageId=0996b43f8036e73c

Intermittent charging

I guess this means you can be driving down the road and the battery light on the dash will light up and go away now and then!

Got any codes?

Voltage drop test NEG and POS (loaded) may be a good place to start! Try to get a reading when the dash light is on and off!  This might give you some direction!

[wayne petty]

Intermittent charging

perform this 4 part voltage drop test...   just to prove that everything is hooked up properly.. especially the battery cables under the rubber boots.




please throw in an alternator output stud  to the battery positive post..


post results by number

1...__________

2..___________

3..___________

4..____________

alt output to battery positive post.. ___________________