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LB7s use 96volts, LLY 48volts, LBZ 24volts.This was taken from an earlier post.So my question is as follows,Is it important to make sure you batteries are top shelf and not in the least down on voltage?:goodvsevil
 

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What do they use these volts for? Not sure what you mean. All the trucks use 12 volt systems.
 

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LB7s use 96volts, LLY 48volts, LBZ 24volts.This was taken from an earlier post.So my question is as follows,Is it important to make sure you batteries are top shelf and not in the least down on voltage?:goodvsevil
You mistook injector triggering voltage for vehicle electrical system voltage. :rolleyes:

Our trucks run on 12v, same as usual. BUT, if your truck is over 3 years old and still has the OEM batteries, checking them is a good idea.
 

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What I meant by that 96volt was if your 12volt battery system was poor or weak,would it not effect the 96 volt trigger at the injector pulse.Sorry about the way the question was worded.
 

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Hey Guys, I just wandered over from The Diesel Place. I have been following the thread that The Bac references in another thread about injector fire voltage. I bought my truck used in Jan 08., 78,750 miles on original injectors with fairly good records by original owner. He took delivery in April 03, and I just installed the third set of batteries in the truck according to the records, after reading up on the injector issues. I don't know if it makes any difference or not, but I am keeping a hot pair in mine to ward off the gremlins. My truck is covered until April 2010, but with my luck, they will fail for reasons outside the parameters and it will be on my dime. If new batteries every 2 to 2 1/2 years keeps the gremlins away, I will do that.

Jim
 

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Ahh learn something new everyday.
 

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LB7 Vin 1 98 volt's
LLY Vin 2 97 volt's
06 LLY Vin2 LBZ Vin D 42 volt's
 

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So with the voltages stated where you put you leads to read them?
 

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Henry, what are those voltage values for?

FICM voltages are LB7-96v, LLY-48v, LBZ-24v.

What we've found over time with the 03-up trucks is that the new electronics in the trucks are very voltage-sensitive. If you've had the cluster fail to "wake up" when you start the truck you know what I mean.
 

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Injector Operation LB7/LLY( prior to 2006)

The FICM uses two drivers to contol each injector.The High Side Driver(HSD) delivers 93 volts updated to 97 volts to the B+ side of the injector.Each HSD powers four of the eight injectors,Connector C1,terminal3,powers injectors1,4,6,and 7(Bank 1).Connector C2,terminal 118 powers injectors 2,3,5,and 8 (Bank 2).

Bank 1 is on the right side of the engine.The firing order is 1-2-7-8-4-5-6-3.

The Low Side Driver,(LSD) grounds the injector to turn it On.There is one LSD for each injector.

A peak-hold strategy is used to open the injectors.It requires up to 20 amps to open the injector and 12-15 amps to hold it open.

If a circuit fault occurs for a single injector, a P0201-P0208 DTC will set.In addition, A DTC will set for the bank that contains the injector.
A fault on bank 1 (1,4,6,7) will set a P1261 and fault on bank 2(2,3,5,8) will set a P1262.

(Loose one loose them all)
 

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Injector Operation LLY/LBZ(2006 and later)

Note: The FICM function are intergrated into the PCM on the 2006 LLY and the LBZ.

The injectors are operated at 48 volts Gm changed this to 42 Volts and require a peak current of 25 amps to open.The current is reduced to 15 amps to hold them open and then drops to 11 amps to reduce heat in the ECM.

There are four drivers that supply the high voltage to the postive side of the injectors.The injectors are grouped as follows.
Group Cylinders Group DTC
1 1&4 P2146
2 2&5 P2149
3 6&7 P2152
4 3&8 P2155

There is one circuit for each injector to control the ground and turn the injector ON.

If a circuit fault occurs for a single injector,a P0201-P0208 DTC will set.The group DTC will also set and Both injectors in the group will be disabled.

Loose one you will only loose two total
 

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Where did you find that info, Henry? None of that has been posted before....here or the Place.

I got that at a Duramax Seminar class.Also brushing up on the powerstrokes passed my class for those now I need to get hand deep in one lol.

Gm service information has not updated this info all the way, When they do I will post it in the spec area.
 
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