GM Automotive Technicians Technical Discussion and Fixes for Sep 12, 2005

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Open Help Requests for GM

	Help Request	Answers
	1998 Buick Regal LS 3.8L starting VIN: 2G4WB52K8W this vehicle was towed in no start key turn and nothing happen using alldata flow chart check crank signal and pcm bcm fuse is good check crank signal at pcm its good, ground starter enable at pcm the car starts flow chart lead to replace pcm i replace the pcm...	View
	1989 Cadillac DeVille 4.5L no comms VIN: 1G6CD5157K Long one - bear with me. Vehicle arrived for A/C check, "Service A/C" lamp illuminated on dashboard. Being a caddy owner myself, I immediately tried using the onboard diagnostics to gain access to the system, expecting to pull an "F" series code. Using the OFF...	View
	1994 Cadillac DeVille 4.9L ride control VIN: 1G6KD52B7R bought the rear struts, and i the dealership told me to by pass the sss any help would be appreciated	View
	1998 Cadillac DeVille 4.6L Electronic VIN: 1GEEH90Y2W if the a/c system is sitting on 60 degree's you turn key off 15 20 min later turn key back on the temp go's from 60 degrees' to 90 degree's without commanding it to . removed control head tested voltage and v dropped grnd's no problem found , no trouble code's...	View
	1990 Chevrolet Corsica LT 3.1L Hesitation, Surge, Cuts out VIN: 1G1LT54T5L Here is a mystery to me. I have this Corsica here that intermitently under load goes fubar. Road testing this vehicle the o2 MV go down to 0 valve train gets noisey and vehicle loses all power. have tested just about everything with no results found. replaced ... Trouble codes: 44 (lean exhaust)	View
	1992 Chevrolet G20 Chevy Van 5.7L No Start, Cuts out, Stall VIN: 248A7RVL81 i have checked all ingtion system is not losing spark even changed icm and still stalls.check fuel presuure in spec but when van stall loses all fuel presure and when you try to start no inj pulse until key is rest then will start every time then stall in 30 s...	View
	1992 Chevrolet G20 Sportvan 4.3L MIL Lamp on, running lean VIN: 2GBEG25Z1N This Vehicle came in with a check engine light on and a quick scan showed a CODE 13(o2 SENSOR OPEN,SHORTED OR BAD.) I replaced the o2 sensor and cleared the code and let the vehicle go...and lo and behold it came back and you guessed it...the light was on and ... Trouble codes: 13	View
	1993 Chevrolet K1500 Cheyenne 5.7L Poor Idle Quality VIN: 2GCEK19K2P This vehicle has an intermitant rolling idle. It will rev up and down about 3to5 times and then go back to a normal idle. It may take up to 2 hours for this to occur. All scan tool data looks normal when this occurs and fuel pressure remains constant. The only...	View
	1993 Chevrolet C1500 Cheyenne 5.7L door locks VIN: GCDC14K4P2 while replacing a window motor, The wiring for the door lock fell out of its connector shell. I put the wires back where I thougt they should go now the door will lock/unlock with security system, And only lock with the button depressed it will Not unlock when...	View
	1993 Chevrolet Camaro 3.4L No Start, Poor Idle Quality, Cuts out, Stall VIN: 2G1FP22S4P Car will cut out at idle & under load, usually all of the time. But, at times, car will run fine (even for 20 miles or so). At first, it would cut out intermittently, but now we can get it to act up almost all of the time. It acts like ignition is cutting out....	View
	1997 Chevrolet Malibu 2.4L Misfire, MIL Lamp on VIN: 1G1ND52T8V I have a misfire on no, 3 cyl not all the time car was at dealer 2 weeks ago for a no start they put a bcm in i saw the bill ... anyway the customer then had the coils the tower and plugs and boots replaced by someone else the he brings it in to my place and s... Trouble codes: 300 (random misfire), 121 (tps out of range)	View
	1997 Chevrolet Venture 3.4L compressor VIN: 1G12345678 Van came in with no cooling.Leak test found compresser shaft seal leaking. Replaced compressor with used one (cust, request) and replaced orfice tube.Came back next week with system freezing up after about 20 min of driving.Presures normal,fan works ,replaced ...	View
	1999 Chevrolet Tahoe LS 5.7L Misfire, MIL Lamp on VIN: 1GNEC13RXX Thanks in advance for your help! This vehicle came to us 6 months ago with a P0300. This is the first one we ever converted from csfi to mfi per factory tsb 00-06-04-003b. We keep geting a P0300 after customer pulls a steep hill under load. We have replaced ca... Trouble codes: P0300 (multiple missfire)	View
	2001 Chevrolet Suburban 2500 6.0L tech2 connection to the car VIN: 3GNGK26U6Y I cant get into the computer in the car, still we have the nevest updating in our computer.tech2. It wont let me into the air bag section. the air bag light is always on.	View
	2001 Chevrolet Silverado 1500 4.8L Poor Idle Quality, hard start VIN: 1GCEC14V4Y Truck starts ok when cold, idles normal and runs fine. After the is shut off for a for a short time (3 minutes) it will crank and start after aprox 30 seconds of crank time and run rough. If it sits for about 3 hours it is ok. I check the injectors for leaking...	View
	1991 Geo Tracker 1.6L No Start VIN: 2CNBE18U2M i need help this is one of those cars that someone else couldn't fix. i have three of the basics to make this thing run except injector pulse. the computer has power and ground (according to alldata has no power or ground coming from ecm for inj pulse also ohm...	View
	1990 Oldsmobile Cutlass Supreme 3.1L No Start, Cuts out, Stall VIN: 1GMBP2YT22 HELP... my first post so fogive me if it's not what you are used to. I have a fine chariot of a 1990 ols cutlass w/3.1l mpi. It runs great...for about 10 minutes. I can't even say it gets hot, but more like warm. Wathcing the snap on scanner it seems the rpm s...	View
	1999 Oldsmobile Intrigue GX 3.5L cylinder head or camshaft VIN: 1G3WH52H6X the noise seems to come from both ends of the engine at the rear cylinder head and lower down as well but I didn't want to just start tearing engine down and waste customer's money . Customer suggests he would sooner replce engine instead of tearing it down ju...	View
	1988 Pontiac Sunbird SE 2.0L No Start, Poor Idle Quality, Stall VIN: 1G2JD11K3J this car is driving me nuts. car came in 2 weeks ago with a stalling complaint. car never made it here we ended up towing it in. found no spark replaced module cap, rotor car started test drove gave car back to customer. 2 days later cust. calls car wont start...	View
	2001 Pontiac Aztek 3.4L Misfire VIN: 3G7DA03E21 We replaced the intake gaskets on this vehicle. Then the customer returned saying the MIL was flashing and it was running poorly.We scanned it and found multiple misfires. we then replaced the wires and plugs. The misfire went to #1 cyl. We checked the coils a... Trouble codes: P0300 (Multiple cylinder misfire)	View
	2001 Pontiac Grand Prix GT 3.8L Surge, Misfire VIN: 1G2WP52K21 help me i'm an ex gm tech. no ses light the vehicle only misses go up a mountain with light thottle at 50 mph with tcc lock up and misses looking at the mt2500 on all 6 cyl going down a flat road its not noticed. the customer lives on the mountain. the tcc cut...	View

Fixes & Summaries for GM

	Fix/Summary	Answers
	1987 Buick Century Limited 2.5L No Start VIN: 1G4AL51R3H after the weekend and reading replies, i was not getting any communication from new ecm. i swapped ecm's and now have communication. vehicle started right up. wish i could explain more what happened but why ruin a good thing. either the contacts were worn on t...	12
	1993 Cadillac Eldorado Touring 4.6L Surge, MIL Lamp on VIN: 1G6EL1290P I want to thank all who offered help with this. The problem turned out to be the 'a' wire going from the ign. module to the crank 'b' sensor. We created our own problem when replaceing the Ign. module. The wire got pushed out a little bit so at idle or light c... Trouble codes: 83 (crank sensor a/ b).	5
	1987 Chevrolet R10 Custom Deluxe 4.3L Hesitation, Cuts out VIN: 1GCDR14ZOH ok, thanks to all of the members that have helped me with this problem. it was the distributor, customer wanted a complete reman from the dealer installed, runs like new. as for the fuel pressure, rechecked after dist install, and it was still at 17 psi, check...	12
	1997 Chevrolet Lumina 3.1L Poor Idle Quality, Misfire, MIL Lamp on VIN: 2G1WL52M3V very sorry! i couldn't get the vehicle back in time to get more info. i think everyone that replied had good info. thank you! i will try to update when i finally have answers. we think i have a valve problem since it had a plugged injector for too long and pro... Trouble codes: P0300.	12
	1998 Chevrolet Blazer 4.3L Blend Door VIN: 1GNDT13W4W This must be a little known secret, but after replacing the blend control motor which can be done by just 'tilting' the dash back and reaching through the glove box opening. No need to remove any of the dash pad as the motor only has two screws. The trick, m...	7
	2000 Chevrolet Silverado 1500 5.3L MIL Lamp on VIN: 1GCEK19T2Y Well, this one is fixed. Thanks to many of you talking about the vent soleniod. We did check all the lines for external leak by pressureing up the tank and soaping all the lines to the canister. None was found. After removing the vent soleniod and seeing all t... Trouble codes: P0446.	7
	2000 Chevrolet Venture 3.4L Transmission VIN: 1GNDX03E6Y you guy did it again. I have fixed the transmission problem. Lane, Serge and Bruce, you guys hit the nail right on the head. I functional checked the solenoids-all worked normal. I opened the transmission pan-found piece of metal from the transmission brake ba...	3
	2001 Chevrolet Prizm 1.8L exhaust valve VIN: 1Y1SK52831 after reading through emails, talking to a toyota service manager, nobody had a real similar experience. we did pull cylinder #3 and #4 piston for comparison and found #4 oil ring stuck in piston groove, which made me feel better about oil useage but not the b...	7
	2001 Chevrolet Blazer Xtreme 4.3L door locks,horn VIN: 1GNCS18W61 We checked all grounds and did not find a concern.It an intermitant with no codes in any modules.We have horns disconnected temp. and will try to repair this car again on cust next visit.	4
	2002 Chevrolet yukon 6.0L blows fuse VIN: 1GKFK66U12 thanks for all the help we drop the tank and the pump had signs of arking we replaced the pump and harness and the truck has not blown a fuse and test better now thanks a lot for your replies	16
	2004 Chevrolet Colorado LS 3.5L Lighting VIN: 1GCDT19604 hi guys. thanks for all the info. scott from texas was right on the money. bcm was bad. after i got scott's email i checked my wiring again just fine. them body control modules are just in a plastic housing so i open it up & the computer board had corrosion at...	2
	1997 GMC Savana 1500 5.7L 3-4 shift VIN: 1GDFG15R5V After checking fluid and finding it burnt replaced transmission. All is fixed. Thanks to everybody that replied.	9
	1999 GMC Jimmy SL 4.3L abs VIN: 1GKDT13W9X We'll after much time hunting down this fix, I hate to say it but I had to replace a sensor that had a good waveform, with a known good part. I drove this car with a scanner, found no problem. I scoped both front wheel sensors and the waveform looked good. Now...	5
	1985 Pontiac Firebird 2.8L Excessive Emissions, Poor Idle Quality VIN: 1G2FS87S2F had some good replies, most said regulator or return, few said a pump. i tried two new aftermarket regs. i hooked up a couple of similar fuel rails from other gms to the cars fuel lines, with no luck. i checked both lines coming from the tank, i even ran the r... Trouble codes: 34 (maf sensor or circuit too low).	12
	1997 Pontiac Firebird Formula 5.7L Radio, windows VIN: 2G2FV22P3V BCM fixed the problem. Chris and Dennis, your comments put me on the right path. I found code 23/33 (RAP shorted to ground or battery). Wiggling the harness connectors at the BCM would produce the problem on command. We ordered a new one from our dealer and in...	3

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