I've been trying to troubleshoot this exact same problem with a repair shop but I don't know where to get the details on the problem. This doesn't seem to be a TSB yet it is listed under TSB's on this website. Any help would be greatly appreciated. Has anyone else experienced this type of problem before?





1999 Chevrolet Blazer

Bulletin #:
3777

Sequence #:
10018585

Date:
01/01/1901

Component Name:
110000 electrical system

Make:
Chevrolet

Model:
Blazer

Year:
1999

Summary:
Fuel and temperature gauge inoperative, low fuel and battery light on, prndl inoperative. *tt

 

im guessing your fuel gauge does weird things. like jumping around showing full when its not things like that. the most common cause is a bad fuel sending unit. most of us have all gone through it.

 

Just contact your local repair shop or the local dealership. They can give you a print out of this. Take the TBS number with you or call them.

If you have no luck let me know. I can hit my local dealership to get you a copy of it. They give me loads of things. Reminds me I should set them all up with a free lunch one of these days. They have been supper helpful with TBS info and stuff.

 

We have searched the TSB on alldata.com but it doesn't conform to a GM TSB number. I would be in your debt if you could get information on this. My repair shop looked at the problem this morning. Found out the power to the computer connection under the dash is dead as well. They can't read the computer. All the fuses checked out fine both visually and with a test lite.

I have searched these forums but have not come up with anything conclusive.

Buy them lunch for and send me the bill if you can get the info.....

 

Here's what you are looking for (I think....lol):







Subject:
Fuel and Temperature Gauge Inoperative, Low Fuel and Battery Light On, PRDNL Inoperative - keywords charge cluster dash electrical fuse generator indicator IPC lamp voltage wire #PIT3777 - (11/10/2005)

[align=left]



Models:
1998-2000 Chevrolet S-10 Pick Up and Blazer [/align][align=left]




1999-2000 Chevrolet Silverado [/align][align=left]




1998-2000 GMC Sonoma and Jimmy [/align][align=left]




1999-2000 GMC Sierra [/align][align=left]




1998-2000 Oldsmobile Bravada [/align][align=left]




Equipped with 4.3L L35 only [/align]


[hr]

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
The fuel gauge and temperature gauge are inoperative and the low fuel and battery lights are on. The PRNDL indicator is inoperative on A/T vehicles. These symptoms can be intermittent. When using a scan tool the inputs are normal when viewed on the powertrain data list, but read zeros when viewed in I/P data list. The gauges will sweep when using the scan tool. This can be caused by an open in circuit 241 to the VCM connector C4 pin 13. This is the ignition 3 feed to the VCM. It is one of the inputs used to determine the ignition lock/switch position. When this circuit is open the VCM sees the switch as always in the crank position, while in this mode the class 2 serial data is in a reduced function state, the Tech 2 will still communicate with the various modules and no DTCs will set.
The following is a matrix indicating what inputs are used to determine the ignition switch position at the VCM.





Position

Ignition 0

Ignition 1

Ignition 3


Unlock

B+






Run

B+

b+

b+


Crank

B+

b+


Recommendation/Instructions:
Check for B+ at VCM connector C4 pin 13, this circuit 241 should only have battery voltage when the ignition switch is in the run position.
Note:Both the 2 wheel drive and 4 wheel drive S/T vehicles with a 4.3 L engine use fuse #15 (4WD) in the IP fuse block and the related wiring (circuit 241) to the VCM for this crank input.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.





GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.


WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

 

^^^^ This dude's a beast^^^^ Luckily, I don't have this problem, but i'm saying "thanks" anyways lol
Oh, and when are you gonna posting some burnout vids of the Landau?

 

This summer when I get the car back out of the garage....I'm going to need new rear tires anyway, (one is worn pretty badly from before I put the posi in) so I intend to get my brother to video the Caprice smokin' both of the rears...until one pops! I hope it don't tear my quarter panel off...

 

Wow, this info is great! Thank you very much lastcoupe. I will have my repair shop review this and see if they can figure out what's going on. They suspected something with the ignition switch before I read this. Hopefully, they can figure out why the ECM is not communicating with the adapter under the dash. There is still no power. Hope I don't have to replace the computer module.

 

Update to my problem with the computer port under the dash. Did you know the cigar lighter fuse powers this port? I do now. I must have needed the same amperage fuse for something else because it didn't have one and I don't use the cigar lighter for anything.. I put a new fuse in the cigar lighter slot and bingo, the computer port works again. Go figure!

Thank you GM for not putting this information in your owners manual.

[:@]

 

Yup, it's a common known fact that GM combined the power circuit for the DLC with the lighter and they aren't the only manufacturer to do so. I find it difficult to understand how this is GMs fault because you removed the fuse after which you said checked out fine both visually and with a test light... Going along with a phrase used by Bill over in your other thread about the OBD2 port power, if GM were to document EVERY component on each circuit in the Owners manual, it wouldn't fit in the glovebox... But then again, that's what the Service manuals are for...

I also do not know how a 'shop' missed the missing fuse either... When attempting to diagnose a power supply issue, you should first ensure that ALL fuses are installed.

Oh yeah... *HOLY OLD THREAD*