GM Automotive Technicians Technical Discussion and Fixes for Feb 12, 2009

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Open Help Requests for GM

	Help Request	Answers
	1989 Buick Reatta 3.8L Poor Idle Quality, Hesitation, Surge, Stall, Misfire VIN: IG4EC11C8K this vehicle came in for stalling. Had a code for maf sensor but signal is good. checked for vac leaks and found large leak at intake manifold gaskets (repaired it). Vehicle still stalls and runs very lean o2 sensor test confirms this as voltage remains at or ...	View
	1995 Buick Park Avenue 3.8L Excessive Emissions, No Start, Stall VIN: 1G4CW52K2S no start. cranks good.spark plugs are drownded with gas.removed spark plugs and cleaned. still no start. plugs again flooded.no codes in computer system. all scan data looks good.no leak down on injectors base pulse with on cranking is 4.4 ms.tested ignition c...	View
	1997 Buick LeSabre Custom 3.8L Misfire VIN: 1G4HP52K9V fellows i have a buick kicking my --- it misses at high rpm, mostly above 2000. some what on decel although not as badly. if you hit the entrance ramp to the highway and floor it, it will register several hundred misfires on 2&5 within a minute. i have checked... Trouble codes: P0300	View
	1997 Buick LeSabre Limited 3.8L oil presure VIN: 1G4HR52K3V hi guys... car came in for no start.found intake let go.remove and replace upper and lower gaskets and plenium.changed oil 3 times.no more coolant found in oil.now car starts and runs good when cold but when hot looses oil presure.cold presure is 40psi once ho...	View
	2001 Checker MONTE CARLO 3.4L blower motor risisstor VIN: 2G1WW1ZE71 heater control only works on high and not in positions 1,2,3 or 4. i the past year we have put in two new resistors already and now it's back again. i don't have a amp meter to check the blower motor draw but i'm leaning towards the blower motor drawing to muc...	View
	1996 Chevrolet C1500 Suburban 5.7L No Start VIN: 1GNFK16R7T I have this 1996 Suburban 1500 with a blown fuse, the ECM-B fuse. 5 or 6 months ago it came in with this fuse blown, no fuel pump working. We replaced the fuel pump and it has been fine until now, the fuse blew again. Replaced it and the pump runs, although af...	View
	1999 Chevrolet Astro 4.3L ball joints VIN: 1GBEL19W8X Does anyone have an easier way of getting these damn rivets out of control arms after the head is cut off is there a special tool for pressing them out on the car	View
	1999 Chevrolet K1500 Suburban 5.7L Poor Idle Quality, Hesitation, Surge, Cuts out, MIL Lamp on VIN: 1GKFK16R1X Thanks in advance for taking the time to read and respond to this one. This Surburban is giving me a major headache! Customer tuned it up himself and replaced the listed parts. Came to me running rough, checked cap and rotor and found rotor loose, fixed that ... Trouble codes: P0171, P0340	View
	2000 Chevrolet Venture Warner Bros. 3.4L cooling system VIN: 1GNDX13E5Y Customer came in with overheating problem and complained of coolant loss. Pressure test showed no vissible leaks (as well as, no pressure drop) to the exterior. Oil looked normal. Over flow tank was completely filled up with coolant (came running out when I op...	View
	2000 Chevrolet Blazer LS 4.3L 1-2-3-4 shifts-lean o2 sensors VIN: 1GNDT13W7Y this thing came in with no down shift if you shift it man. it shifts down it also had a code p1875 in it i removed the wire harness to check for breaks or shorted wires found nothing now code p1875 does not come back but still shifts very fast if you look at t...	View
	2001 Chevrolet Monte Carlo SS 3.8L air flow VIN: 2G1WX15K21 cust complain noy blowing hard out of vents checked other cars seems to be same	View
	2001 Chevrolet Tahoe 5.3L speedometer VIN: 1GNEC13T81 Found that vehicle has vss out from pcm, don't know what aftermarket radio could do to stop speedo, It seems to be cluster, but expensive has anyone seen this problem before, thanks in advance!	View
	2001 Chevrolet Malibu 3.1L Surge VIN: 1G1ND52581 hey guys need some help with this one. we replaced the head gaskets do to overheating every thing was routine but 3 day later (i dont think it related to the repair but dont know ) it developt a surge on accl. i got it to do it twice. once it was on light trot...	View
	2002 Chevrolet Venture LS 3.4L no spark VIN: 1GNDX03E42 was driving good, start misfire I drive like 50miles home then start overheating, at home I put lower inteke gaskets put everyting back and guest what NO START CHECK FUEL PRESSURE OK, CRANCKING GOOD BUT NO START I CHECK SPARK,THERE IS NO LIGHT, ANY HELP WILL...	View
	2004 Chevrolet Suburban 1500 Z71 5.3L tpm VIN: 1GNFK16Z34 GM techs I cant get TPM system to go into learn mode,my tech 2 says to KOEO foot on brake turn exterior lamp switch from off to on 4 times in 5 secs.then a chirp will be heard from horn then i can use tool to relearn position of sensors or check for signal str...	View
	2005 Chevrolet Express 1500 LS 4.3L No Start VIN: 1GCFG15X65 hey guys! this van died while drivingat 50 mph comming to an exit slowing down. it would not start back up, and the batt was dead all the way, i mean no lites no nada! lol. would not even jump start. i put a batt in and it was fine, as far as cranking ect. but...	View
	2007 Chevrolet HHR LS 2.2L MIL Lamp on VIN: 3GNDA13D47 Car came in because it failed the state emissions test, found p0171, smoke tested and found no vacuum leaks, car runs like a champ, STFT changes between -3 to 5 %, but LTFT is almost always pegged to 30%. Found a TSB that says to replace injectors with a diff... Trouble codes: P0171	View
	1994 GMC Jimmy SLE 4.3L 2-3 shift VIN: 1GKDT13W0R hi we have a 94 gmc jimmy here the trany dose not have a 3rd gear. when driveing the truck it will just tach out when it should go into 3rd. it will go in to 3rd if you manualy shift it. the trany pan was leaking and it was 3 quarts low before this happend. sh...	View
	1997 Pontiac Sunfire GT 2.4L runs rich VIN: 1G2JD12T8V hi guys, my #1 tech on holidays. this vehicle came in barely running, can get to run better if play with accelerator but runs rich, also backfires sometimes through the throttlebody, i am thinking that could be timing chain related but would like some ideas be...	View
	1999 Pontiac Grand Am SE 3.4L Starting VIN: 1G2NE52E9X this car was hauled in with very little imformation. colege girl her dad trailered it to me. intermitant no start. started with the basics, good spark , fuel pressure 43psi koeo. crank rpm present. being a 3.4 was unable to check injector pulse at injector eas...	View
	2003 Pontiac Vibe 1.8L headlights VIN: 5Y2SL62873 customer states headlights come on by themselves while vehicle is sitting in driveway turned off, first time cust operated dimmer switch and lights shut off, second time customer had to disconnect battery after operating headlight and dimmer switches. I am ass...	View
	2004 Pontiac Grand Prix GT2 3.8L Blower Motor VIN: 2G2WS522X4 Vehicle came in with new blower motor and resistor. Blower still not working. Scaned bcm had code U1000 & U1153. Cleared codes. U1000 comes right back. When i test for power at the blower motor wires i have 4 volts at the feed wire and ground. When i test the ...	View

Fixes & Summaries for GM

	Fix/Summary	Answers
	1997 Cadillac Eldorado 4.6L head gaskets VIN: 1G6EL12Y7V THANKS EVERYONE FOR POSTING I got a lot of useful tech info. thanks to thoughs of you that said Cadilac requires installing inserts when changing head gaskets. Thanks to you guys that had experience to post a est. labor time that sure helped to tell my custome...	35
	2004 Cadillac CTS 3.2L MIL Lamp on, will not run evap . VIN: 1G6DM57714 A thank you to [...], kj1058, d kasura, blackhole, shop@planethax, and a [...]. I have waited until consumer had car for a week to be sure that repair is complete and correct. A) this vehicle really needs to be between 1/4-3/4 fuel level or it will absolu... Trouble codes: U0001.	7
	2005 Cadillac SRX 4.6L steering VIN: 1GYEE63A25 had customer take back to cadilac they said new power steering pump was defective brought it back and i put another pump on it and it did not fix it customer is contacing gm customer relations to see if they can get this resolved thanks for all the respones i ...	9
	1996 Chevrolet P30 Fwd Cont 7.4L Mechanical VIN: 1GBLP37JXV The responses i got were not much help. I realize the vent closing problem is do to loss of vacuum. I checked the cat's and they do not seem to be the problem because inlet and outlet temps indicate they are working properly. I tested the KV's for all cylinder...	7
	1999 Chevrolet Express 3500 LS 5.7L No Start VIN: 1GAHG39R8X I removed the timing cover on this truck and was disappointed when nothing much seemed out of the ordinary. The reluctor ring on the crank was intact and secure, no measurable thrust on the crankshaft, no chunks of metallic debris floating about. I did find ... Trouble codes: P0336, P0339.	9
	1999 Chevrolet Tahoe LS 5.7L TCC Solenoid VIN: 1GNEK13R7X Thanks to all that replied to this post. After giving the customer all of the options, customer has decided to replace the entire transmission with a GM rebuilt unit. I hope this solves his problem. He figure diagnostic time was a waste. We will see if ...	14
	2001 Chevrolet Impala LS 3.8L fast idle VIN: 2G1WH55K01 well after testing everything i could think of finally decided to go to computer which is located in the airbox. found a mouse nest with several chewed through wires. repaired wires and all problems are fixed. thanks to all who replied! Trouble codes: P1810.	11
	2003 Chevrolet Trailblazer LTZ 4.2L ignition lock cylinder VIN: 1GNDS13S53 Ended up knocking off black part on end of lock cylinder and using a small pick was able to push the bar on the side of the cylinder in enough to get the cylinder to turn to remove it.	16
	2006 Chevrolet Silverado 1500 LS 4.3L Air Bag System VIN: 3GCEC14X96 Thanks to those who responded, after several tries to locate the correct resistors without luck I took the vanatage to the circuit. Found intermittant 30 ohms of resistance in the white wire between the srs controller and c221 for the drivers deployment loop. ...	2
	1995 Geo Prizm 1.6L Misfire VIN: 1Y1SK52561 well the coil fixed it - doesn't make any sense to me as the miss was always #2 never moved & only after warm up thanks to all who helped out	7
	2001 GMC Jimmy SLE 4.3L Surge, Cuts out, Misfire, MIL Lamp on VIN: 1GKDT13W81 Shimed crank shaft position sensor with [...] shim car didntrun bad Trouble codes: P0335.	6
	2003 GMC C4500 Topkick C4C042 6.6L no accelerator funct VIN: 1GDE4E1123 FIRST THANKS TO GARY,ANDREW,GAIL,JOHN,AND WILLIAM THERE WERE NO OVERLAPPING SUGGESTIONS,CHECKED FOR OUTSTANDING TSB'S, CHECKED OUTPUT SIGNAL OK, CHECKED PTO SIGNAL OK, CHANGED FUEL FILTER DI NOT CHECK FUEL PRESSURE REGULATOR AS THIS IS INTERMITTANT THE VEHICLE...	5
	1993 Pontiac Grand Prix SE 3.1L Excessive Emissions, Poor Idle Quality, Poor Fuel Economy VIN: 1G2WJ14T7P Hi folks Sorry it has took so long to close. We found the throttle shaft worn, and it caused the minimum idle to be off, and tps to change voltages when the throttle returns to close. We replaced the iac for the high idle concern and reset the minimum idle. Th...	16
	2000 Pontiac Grand Am SE 2.4L Horn VIN: 1G2NF52TOY Hi Guys sorry for the short post with out telling you what I had allready tried. I did print out the wiring and checked it out OK, look at the shifter cable and ignition lock cable to see if wires where chafed OK, Look for wires grounded or chafed in engine co...	2
	2000 Pontiac Bonneville SSEi 3.8L Starting VIN: 1G2HZ5412Y The fix for this car was a new Theft module, 2 new keys and a relearn all done by local GM dealer because we do not have a Tech 2 scanner.The no start was because of the VTD(vehicle theft deterrent system) and the dead battery was because the VTD was not allow...	9
	2003 Pontiac Grand Prix SE 3.1L Mechanical VIN: 1G2WK52J83 Thanks to all of you for helping us decide what direction to go on this car. I informed the customer the oil pump relief valve must have stuck causing excessive oil pressure. The pump was replaced 6 months ago by another shop. Robert from Onterio mentioned ...	8

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