GM Automotive Technicians Technical Discussion and Fixes for Jan 13, 2010

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Open Help Requests for GM

	Help Request	Answers
	1988 Buick Electra Park Avenue 3.8L MIL Lamp on VIN: 1G4CW51C1J i have a problem with this 1988 buick park ave. we have replaced the ecm, with gm part, tps, all the wiring test good but no voltage to tps on the 5 volt wire. all other sensors that use a 5 volt reference is good and 5 volt reference is present. haven't repla... Trouble codes: 22 (tps signal voltage low)	View
	1995 Buick Riviera 3.8L No Start, Stall VIN: 1G4K22K7S4 Hello all! I am wanting some insight on the intermittinent buick. This car dies and normally restarts right away with no hesitation. It fails very little on a cold day, but in the shop or on a warm day it fail a lot more. It has to be good and hot and will onl...	View
	2001 Buick Rendezvouz 3.4L Poor Idle Quality, Misfire, MIL Lamp on VIN: 3G5DBO3E12 now the car runs bad has a po300 random misfire.my helper for some reason thought he should remove the harmonic balancer could we have upset the air gap for the sensor? Trouble codes: P0300	View
	2002 Buick LeSabre Limited 3.8L Suspension VIN: 1G4HR5K72U Hi,I'm trying to find info on this. On the panel it will say, Service stability System . It comes on about one time a week. Just driving straight down the road at about 30 or 40 mph. Car feels fine. I did not think the 02 Buick had this system but I could be a...	View
	2004 Buick Century Limited 3.1L MIL Lamp on VIN: 1G4HR54K14 Have a repeat offender PO442 Evap leak, smoke checked several times, looked for connection problems as suggested in archives, finding no leaks, suspect tank pressure sensor, except for the vent solenoid nothing fails when in shop and takes several weeks for li... Trouble codes: P0442	View
	1996 Chevrolet Tahoe 6.5L Trans,tech,speedo VIN: 3GNEK18R7T Greetings, The owner of this Tahoe was driving along when suddenly the speedometer and the techometer quit working. At the same time the transmission quit shifting and seems to be stuck in second or third. We've checked all the fuses and took it for a test d...	View
	1996 Chevrolet Blazer 4.3L No Start VIN: 1GNCS13W1T Customer said truck is hard starting first time in the morning. Fuel pressure is good (55 to 60) and will maintain 55lbs for a couple of hours(at rest). Pressure does drop off to 0 overnight but returns on the first key on. Spark output seems fine (jumps an in...	View
	1997 Chevrolet Blazer LT 4.3L Cuts out VIN: 1GNDT13W3V This vehicle occasionally stalls, usually at idle. Before it stalls, the tach will fluctuate and then the truck will stall. The truck restarts immediately. The fuel pump was replaced 6 months ago and the plugs, cap, rotor and wires were replaced 2 days ago. Th... Trouble codes: P1106, P0108	View
	1998 Chevrolet Astro 4.3L Misfire VIN: 1GNDM19WXW Thanks in advance. I have a simple igntion arc coming from the bottom of the coil wire to the coil. It only happens when trying to start cold. It will continue to crank until it catches which takes 1 to 4 key cycles. Once it starts, there is no problem. It is,...	View
	2000 Chevrolet Blazer LS 4.3L hvac VIN: KJKIUI8976 THIS [...] IS THE SHOP/COURTESY VEHICLE...coolant guage only getting 1/4 up...when i removed thermostat housing to change thermostat very little coolant came out despite rad full and expansion tank full...therefore when i tried to top up rad after thermos...	View
	2001 Chevrolet Silverado 1500 5.3L compression VIN: 3GNFK16T11 vehicle towed in for stall. restarts but runs roung. found all cylinders on right bank misfiring. compression between 50-80 psi. left bank 200-220 psi. found converter plugged. removed, cleared cylinders and retested. right bank still low compression. code(s) ...	View
	2001 Chevrolet Malibu 3.1L instrument cluster VIN: 1G1ND52J51 Hello this Malibu has an intermittent problem happened last night after I started the car, in the dash operational=RPM guage, cluster lights, odometer. Inop=coolant guage, fuel guage, also low fuel dot on. Indicators stuck on= theft system, sevice engine soon,...	View
	2002 Chevrolet Venture LS 3.4L Cooling Systems VIN: 1GNDU3E62D van came in 1 mth ago, overheating. found low coolant added 2 liters and could not locate any leaks. customer drove again. problem returned, coolant bottle is full but rad is low and system is air locked. after bleeding many times and testing with water pump b...	View
	2004 Chevrolet Avalanche 1500 5.3L Excessive Emissions, Poor Idle Quality, Misfire, MIL Lamp on VIN: 3GNEK12T14 Truck is sort of intermittant but it always adds fuel to bank 1, and around 25% at idle though the pulse width looks the same as the other bank. Will sometimes run very well, next time VERY rough idle. Usually, #1 cyl will miss most, and some for #3, but now w... Trouble codes: P0300, P0171 (Lean bank 1)	View
	2004 Chevrolet Trailblazer LS 4.2L Mode Actuator Motor VIN: 1GNDS13S34 This vehicle came in with the mode actuator door only switching between floor and defrost. Any setting other than these two produces no change. When the mode selector switch is set to blow on both vent and floor the engine begins to stumble and if the mode sel...	View
	2005 Chevrolet Equinox LS 3.4L rear drive shaft VIN: 2CNDL73F25 just looking for input on rear drive shaft problems on these equinox. i've checked with local drive line shops and there is no rebuild kit for the front cv joint on the rear drive shaft. you have to buy the whole drive shaft from dealer at $1100.00. has anyone...	View
	2005 Chevrolet Silverado 1500 5.3L Misfire VIN: 1BGTYUII66 Fuel trim bank 1 is stuck at +25% WITH IGNITION ON and engine off. I have dis-connected battery and tried again, same results. STFT are at 0 on both banks. Plugs are black with soot on bank 1, beautiful on bank 2, cant find any intake leaks from the outside, ... Trouble codes: P0300, P0171	View
	2007 Chevrolet Corvette 6.0L anti theft VIN: 1G1YY36U67 The DIC displays NO FOB with either (2) FOB in hand. Would start with FOB in glove box slot. Tried reprograming FOBs and now will not start with FOB in glove box slot. Tried both the unboard reprogramming method and the Tech2 pass thru system. FOB will work on...	View
	2003 GMC Yukon SLT 5.3L Instrument cluster/ Heater blower VIN: 1GKEK13Z73 Hello techs! The instrument cluster on this Yukon is dead. Only the 'check engine' light and dash lights work. The heater blower works intermittent, don't know if it's related. BCM has U1000 (class 2 data link malfunction) as a current code. Heating/AC module ...	View
	2004 GMC Sierra 3500 6.6L No Start, MIL Lamp on VIN: 1GTHK33214 vehicle towed in with no start. checked codes had p0335(ckp circuit a), p0105(lost communication ficm), p0106(lost communication gpcm). cleared codes. po105 comes back everytime, only have to turn key on for code to come back. vehicle cranks over great, but no... Trouble codes: P0335, U0105 (lost communication fuel injector control module), U0106 (lost communication glow plug module)	View
	2005 GMC Savana 1500 5.3L stoping distancee VIN: 1GDFH15T65 thank you in advance. customer is complaining about his van stopping. on test drive i did find a very soft brake pedal and at higher speeds you can push brake pedal almost to the floor when stopping. if you mash on brake pedal as hard as you can you cannot mak...	View
	2006 Hummer H3 3.5L Excessive Emissions VIN: 5GTDN13636 Our customer want to change fuel filter. But we're not found the fuel filter location. We uses GM EPC, but there is don't have fuel filter location illustration. The vehicle is Hummer H3 SUV 2006. Can any one tell me the H3 fuel filter's location? And in our r...	View
	1995 Oldsmobile Aurora 4.0L leak VIN: 1G39R62C4S There is a major trans fluid leak running out the bottom of the bell housing. The leak is a pressurized leak ( pumps out at least 1 quart per 90 seconds while engine is running) The leak started suddenly on a very cold day here in southern MN. I thought the pu...	View
	2001 Oldsmobile Aurora 3.5L Poor Idle Quality, Misfire, MIL Lamp on VIN: 1G3GR62H41 Vehicle came in with complaint of rough idle, smooth under all other conditions. We verified complaint, no misfires (a few random ones on cyl #1, very spotty) on scanner at off idle or while driving, but once rpm drops to below approx 1000 constant misfire sta...	View
	1999 Pontiac Grand Am SE 3.4L Mechanical VIN: 1G2NE12E2X Hi all, got this Grand Am that’s giving me a headache. Had never seen this car before and it came in for an intake manifold leaking coolant. Ran it long enough to verify head gasket leak also. Replaced the head and manifold gaskets and head bolts, all surfaces...	View
	2000 Pontiac Grand Prix SE 3.1L Surge, Cuts out VIN: 1G2WJ52J4Y no pending, or stored codes. heavy surge/cuts out @2200-2500 rpm steady throttle. symptom will cease when throttle is opened (rpm/load increased) scope traced tps signal (good, no glitches) monitored crankshaft position sensor (good, no glitches) symptom does ...	View
	2002 Saturn SC2 1.9L Poor Idle Quality VIN: 1G8ZK52772 high idle sometimes,1500-1800rpm replaced iac and decoked throttle body will slowly walk down to correct idle speed but on decel stays high then slowly walks down coudnt find vaccum leaks tps works correctly coolant temp ok --help	View

Fixes & Summaries for GM

	Fix/Summary	Answers
	1993 Buick Park Avenue 3.8L interior VIN: 1G4CW53L3P No fix found, problem is intermittent, smells at random, unable at this time to find any fault with hvac system, exhaust/carpet/ convertor, hood seal, wire looms all normal. Will replace blower motor, it is original, see if helps, will take time as happens onl...	12
	1995 Buick Park Avenue 3.8L door locks VIN: 1G4CW52K9S yes, the door lock relay is located under the driver's seat. big thanks to all who took time to reply, especially kenny [...] for sending me a diagram. the problem i had was that fuse #1 in the relay center (above right kick panel) had a direct short to groun...	9
	1994 Chevrolet Corvette 5.7L Cuts out VIN: 1G1YY32P3R Thank you for your input! The majority of IATN responses to our help request suggested replacing the lock cylinder and reprogramming the BCM. We reviewed our test procedures, rendered our findings, described the IATN system and the 6 suggestions we recieved n...	7
	2005 Chevrolet Trailblazer LT 4.2L Drive-axles VIN: 1GNET16M55 Found that the transfer case internal pump failed allowing the arm to over travel, which was setting the code. replaced transfer case retested no futher troubles.	9
	2005 Chevrolet Impala 3.4L Steering VIN: 2G1WF52E45 Thanks for all the help & replies,special thanks to michael& jackie for the bleeding air out of system using a vacum pump puting system under 10 inches vacum and turning wheels left to right with car turned off about 10 times,bleed air out.Flushed lines cleane...	20
	2005 Chevrolet Silverado 2500 HD 6.0L Tailights VIN: 1GCHC24U95 First, Thank You everyone for responding. I inspected the ground circuit this morning, and found a loose connection at the frame near the fuel tank. Apparently the ground for the fuel fill nozzle, and the brake harness Share the same grounding location. Possib...	12
	2009 Chevrolet Corvette 6.2L Keyless entry VIN: 1G1YY36W19 After replacing the RCDLR the vehicle appears to be repaired. I believe that it was cold tempature related. Thanks for all the help.	8
	2003 GMC C5500 Topkick C5C042 6.6L Mechanical VIN: 1GDE5E11X3 Hello to everyone that took time to lend a hand, here is the fix. Do you know the metal fuel return lines that run under the valve pan covers? Well as I was removing the heads I was going to pull the injectors out before removing the head bolts and when I went...	5
	2006 Hummer H3 3.5L Wheel sensor VIN: 5GTDN13616 Thanks to all that replied to this request. Yes the ABS code will disable the 4 wheel drive control. My daughter had the left rear wheel sensor replaced at the dealership that she works at part time and has had no problems since. Thanks again George	3
	1997 Pontiac Sunfire SE 2.2L Mechanical VIN: 1G2JB1246V Well it looks like I am putting in another engine. Thanks for all the input I will let them know not to over rev and that its not a race car. Mike	13
	1997 Saturn SC1 1.9L No Start, MIL Lamp on VIN: 1G8ZH1271W I would like to thank every one for their help on this one. With the issue only being first thing in the morning, I had to wait tell it had cold soaked over night to run any test and confirm my repairs. I first checked for leak down yesterday from the fuel pum... Trouble codes: P0133 (O2 Sensor B1S1 Response Too Slow), P0326 (Knock Sensor Out Of Range), P0341 (CMP Sensor Out Of Range), P0351 (Ign. Coil A Problem), P0352 (Ign. Coil B Problem), P0463 (Fuel level Sensor).	16

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