GM Automotive Technicians Technical Discussion and Fixes for Sep 14, 2007

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Open Help Requests for GM

	Help Request	Answers
	1998 Buick Park Avenue 3.8L Driveability VIN: 1G4CW52K4W Actually this issue is with my personal car. If it was a customer, they would probably shot me by now...since I have been working on this off and on for the past 2-3 months. Here's the issue. My 3.8L 1998 Buick hesitates from either a stop...or a roll and go....	View
	2000 Buick Regal LS 3.8L Poor Idle Quality, Cyl 4 misfires VIN: 2G4WB55K14 This will not cause fault codes, but I have a rough idle and high misfire counts for cylinder 4 only when viewed on Tech 2. The counts are higher at idle than when cruising, seems to be vacuum related but cannot find a vacuum leak, with propane or smoke machin...	View
	2004 Buick Rendezvous CX 3.4L Differential VIN: 3E54S58950 Hey guys got a fun one. The AWD disengage light is on i have replaced the valve in the rear end,cleaned the conn, coming through the body,was alot of corrision,now i have the right volts to the act. on the rear. Test drove the car about a mile sure enough the ...	View
	1990 Cadillac Eldorado 4.5L bttery VIN: 1G6EL133XL cust states if vehicle sits for acouple weeks battery goes dead.we have checked for drainsand found nothing. at hook up reading is.33 after ten minuites drain drops to .02amps. at no time did we see anything higher. i'mwondering if something is wakeing up and ...	View
	1993 Cadillac DeVille 4.9L Stall VIN: 1G6CD53B4P This vehicle has an intermittent stalling problem which occurs mostly when the A/C or the heater are on. The vehicle will stall on decel, while turning, and while applying the brakes. Since this problem occurs 10-15 times a day the vehicle has become unsafe to...	View
	1998 Cadillac DeVille Concours 4.6L Suspension VIN: 1G6KF549XW thanks for checking this one out! car came in with service stability light on. it originally had codes c1255, 1281, 1282 and 1287 stored. 1255 indicated an internal problem with abs control module and since all powers and grounds were good, we replaced with a ...	View
	2003 Cadillac DeVille DTS 4.6L MIL Lamp on VIN: 1G6KF57993 The AIR pump is bad due to water/design issues. Is this system covered by 5/55 Warr? No local dealers will cover it. Trouble codes: P0410 (Secondary AIR problem)	View
	2004 Cadillac CTS 3.6L Anti-theft VIN: 1G6DM57784 Hello everybody. Vehicle was towed in after it went to a car detailing shop. Engine was not touched, only interior and exterior were cleaned. When customer went to pick up car it would not start and showed 'starting disabled - remove key' message. Once here we...	View
	1990 Chevrolet P30 Step-Van 7.4L no power VIN: 1GDKP32N1L hello-need to ask a few questions about the ignition system on this truck-we have the base timing set at 4 degrees with connector apart-when we re connect the timing connector back to gether it still stays at 4 degress-i would have thought it would maybe bounc...	View
	1993 Chevrolet Lumina APV 3.8L Cuts out, Stall VIN: 1GNDU06L0P Hi guys this is me again thanks for your help.I replace the coolent sensor with other one the engine check light is off .but the problem with black smoke coming from the E.G.R.&tail pipe was thier.THANKS to you guys I removed the front pipe from the menifuld.t...	View
	1994 Chevrolet Corvette 5.7L cooling fan VIN: 1G1YY22P4R Hi and thanks in advance; I have used this sight many times but this is my first request. I have a 1994 Corvette that runs fine and everything works with no warning lights on. The problem is the primary cooling fan runs all the time even from dead cold. The Mo...	View
	1998 Chevrolet Express 2500 LS 5.7L Misfire VIN: 1GCGG25R3W Ok here it goes. Vehicle will start cold ok, after about 15- 45 seconds starts to skip on #7cyl and an occasion #3 and #4 but very rarely. You can mash the throttle and it cleans out but if you hold it at high ilde (anything above idle) after about 30 sec. sta...	View
	2000 Chevrolet K2500 7.4L password VIN: 1GCGK24J9Y I have a very intermittent no start with this truck. It has a P1631C in the history codes. The enable is on yes and the disable is on no the most likely state is reversed. I have not seen this no start in the shop yet but it has been towed for this condition. ...	View
	2002 Chevrolet Silverado 1500 4.3L blower motor VIN: 1GCEC14W32 the bolwer motor is running strong but there is no air flow thru any of the vents air flow wont blow a match out and all the mode doors i see are working please help thank you	View
	2005 Chevrolet Silverado 1500 5.3L Poor Idle Quality, Surge VIN: 1GCEK19B05 Have this truck that when it idles the idle kind of goes up and down or surges and when you are running down the road seems when you let off the gas pedal keeps wanting to go or accelerate a little then will eventually come down checked for intake leaks found ...	View
	1996 Geo Metro LSi 1.3L MIL Lamp on VIN: 2C1MR5294T Good Morning. We are having a hard time understanding this EGR system. The PO400 code will reset on a 5 mile test drive. We are only getting 4 - 6 inches of vacuum to the EGR valve. Is this enough? All components test out according to Alldata diagnostics. The ... Trouble codes: P0400 (EGR Flow Malfunction)	View
	1997 GMC Jimmy SL 4.3L No Start VIN: 1GKDT13W6V hEY GUYS THIS ONE TOWED IN NO START FUEL PRESSURE KEY ON 60 PSI CRANKING 45 PSI HAVE SPARK I TRIED A KNOWN GOOD COMPUTER STILL SAME PROBLEM HELP PLEASE.	View
	2005 GMC Sierra 1500 Denali 6.0L air bag/rear view mirror VIN: 2GTEK63N75 thanks to anyone that can help i have this denali which belong to my boss, came in shop with air bag light on and compass in rear view not working. scanned air bag system no communication(suspected fuse). found air bag fuse under hood blown. rescan for codes ...	View
	2002 Pontiac Grand Prix GT 3.8L Anti theft VIN: 1G2WP52K32 I need some help on this passkey 3 system. This car has the passkey module on the steering column near the lock cylinder. From what I've been able to find this system has a transponder in the key. Is this correct? If it's in there it must be really small! I ha...	View
	2002 Pontiac Grand Prix GT 3.8L passenger side window VIN: 1G2WP52KX2 Window would not go up or down. Diagnosed as window motor in passenger front door. Replaced window motor. Now it goes up and down but from the drivers door only. Passenger door switch does not work. I don't usually do this kind of work, so not familiar with ho...	View
	2004 Pontiac Grand Prix GT2 3.8L I - Shaft VIN: 2G2WS52294 Hi iATN techs, thanks in advance for the help. This '04 Grand Prix is my sister's car. The problem is the steering noise in the intermediate shaft which I did read on the posted TSB. I have not had the shat out yet. What I want to know is why does to TSB say N...	View
	2000 Saturn SC2 1.9L MIL Lamp on VIN: 1G82Y1271Y will pass test air pump run no amp spikes have vacum to solondid took off air pipe have air come thru to the head can see change in upstream o2 sensor Trouble codes: 410 (sec air)	View

Fixes & Summaries for GM

	Fix/Summary	Answers
	1987 Buick Regal GNX 3.8L piston oil ring VIN: 1G4GJ1175H I very much want to thank everyone who offered their help and suggestions. I heard many suggestions involving the lubricant of many choices and many similar stories, but I opted to take another leak down test after trying my best to give it a chance to "recove...	16
	2002 Buick Rendezvous CXL 3.4L Interior lighting, radio,pwr windows,locks,gauges VIN: 3E5DA03E32 Special thanks to everyone's quick replies. I have confirmed that the BCM Did correct the issues w/ this Rondevoux. We offered to perform the repair but the customer decided to take it back to the puchasing dealer due to the fact that we did not have a Tech 2 ...	8
	2002 Buick LeSabre Custom 3.8L MIL Lamp on VIN: 1G4HP54KX2 Thanks for all the quick replies. I learned something here about MAF sensors--that cleaning them does not work. Even though cleaning it restored the vehicle power, it was not hitting a high enough flow on WOT. New MAF seems to have solved problem, it's been... Trouble codes: P0171, P0131.	20
	2003 Buick LeSabre Custom 3.8L Cuts out, Stall VIN: 1G4HP52K13 Well after 500 miles and two tanks of fuel a new MAF seamed to do the trick. I never actually saw anything abnormal with the readings it just would shut down while coasting or give a slight hic-up at freeway speed. Several replies mentioned MAF so I took a gam...	20
	2000 Cadillac DeVille 4.6L fourth gear VIN: 1G6KD54Y7Y Thanks Guys, I think this old lady will just leave it as is. I got some suggestions about possible shift solenoid problems but since she only goes to the grocery store, doctor appointments and the hair salon, fourth gear is not a priority. The repair money wi...	3
	2004 Cadillac CTS 3.6L Key / Ignition VIN: 1G6DM57794 Thank you all for the help I shipped the vehicle off the the dealer and it was the Ecu they replaced it under warranty. Thanks Again for all the help.	10
	1992 Chevrolet S10 Blazer 4.3L No Start, Cuts out, Stall VIN: 1GCCT13W5N after making new grounds and checking everything that i could possibly do, i have decided that this one is better gone. the customer was not upset, but i am for not fixing it. he has had this thing to 3 dealers and other independent shops. sorry for letting yo...	24
	1994 Chevrolet C1500 Suburban Silverado 5.7L air flow VIN: 1GNEC16KXR Thanks for the help guys, some of the evaporator cleaning suggestions where too scary for me. I know the evap was possibly restricting the air flow but if you saw how meticulously these people clean their cars you would understand why I think this is just anot...	15
	1998 Chevrolet Malibu 2.4L Poor Idle Quality, Hesitation, Cuts out, Misfire VIN: 1G1ND52T3W Thanks everyone for all the replies (14) which led me to solving this problem. I knew that one test which I needed to perform was a fuel pressure test (why in hell does GM not add a fuel test port to many of it's vehicles...wankers!) Here is a really good so... Trouble codes: P0172 (Fuel Trim System Rich).	14
	1999 Chevrolet Express 3500 LS 5.7L No Start VIN: 1GAHG39R6X Thanks for all the help, most were right on the money. The problem was a burt connection, gray wire terminals inside the round connector near the trans crossmember. I found Power going in to connector,but no power coming out,I Bypast round connector with a wir...	14
	1993 GMC K3500 Sierra SLE 6.5L overdrive VIN: 1GTHK33F2P We finally got it. It turns out to reset the TCM we had to set the voltage on the TPS using a DVOM. We started with abase line of 0.5vdc in the DVOM. I also found a poor ground in the wiring and we overlayed the wiring to the TCM. It Took all 3 repairs to make...	6
	1996 GMC C3500 HD 7.4L timing VIN: 1GBKC34J8T Sorry about the long wait, this truck had many problems, bad starter, bad starter cable, bad brakes, too many problems to list, but everything is fixed and the truck is running like new. The timing problem was the distributor was 90 degrees off, I moved...	13
	2000 Oldsmobile Intrigue GX 3.5L No Start, LONG CRANK VIN: 1G3WH52H2Y Thanks to all that replied to this question... Vehicle was fixed by replacing ignition switch. The key to this repair was that while cranking,the check engine light would flash on the dash. When vehicle would not start light would flash and one time wh... Trouble codes: U1016 (commuication error).	4
	1991 Pontiac Bonneville LE 3.8L Cuts out, Misfire VIN: 1G2HX54C2M Several of you were on the right track especially Michael who first responded. The harmonic balancer, replaced by customer, had the sensor rings out of alignment throwing the timing off(defective part)swaped out for new one at the part store and wala it runs l...	8
	2000 Pontiac Bonneville SE 3.8L Brake pads / rotors Rear VIN: 1G2HX54K8Y Well this is a first. No full and complete answer, only a summary. I have contacted the client ad reviewed with them what's going on. the noises has been reduced greatly but still when heated - lots of stop and go driving the groan noise will re appear under h...	6
	2003 Pontiac Grand Am SE 3.4L No Start, MIL Lamp on VIN: 1G2NF52E13 The Grand Am is done,finally. After getting the replies and other information together I felt more confident to diagnose this thing. I started with the normal power and ground checks to the PCM which told me that the module was bad, but when I installed it I s...	7
	2004 Pontiac Grand Prix GT1 3.8L Heater operation VIN: 2G2WP52204 At this point the vehicle has not come back and the customer has expressed no further problems. Thank you all for your input. If it does return I will post again but I don't suspect it will. Based on our assessment of the problem and the help of you guys we di...	14

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