GM Automotive Technicians Technical Discussion and Fixes for Feb 23, 2005

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Open Help Requests for GM

	Help Request	Answers
	2000 Buick LeSabre Custom 3.8L Electric Window, door lock, power mirror VIN: 1G4HP5K9Y4 We got this one last week, customer complaint was the passenger front and both rear the windows door locks and passenger side view mirror are inop, Customer stated this happend all at the same time. But the driver window door lock and side view mirror works, T...	View
	1997 Cadillac Seville STS 4.6L ebtcm VIN: 1G6KY5299V hello all, having trouble with an abs/tcs unit. any help/suggestions appreciated. vehicle came in with abs and tcs lamps on solid. codes: pcm p1602, ipc u1255(current) u1040(hist), tcs no data, rss c1783 c1785. after clearing ipc u1255, rss c1783 c1785, no tcs...	View
	1984 Chevrolet Corvette 5.7L no shut off VIN: 1G1AY0784E Greetings, This vette towed in for new longblock, transplant went well and now the fun begins. In the column, we can turn key and provide power to the dash, and accesories, and turn the key back and shut them off. When we turn the key and actually start the c...	View
	1985 Chevrolet Cavalier Type-10 2.0L No Start VIN: 1G1JE27P2F checked coil and found no spark voltage from the coil but 12 v at the input wire. ground is good and still nothing. i suspect the ignition module and have checked the reference voltage and tested ok. there is no amps/volts coming through the ignition module. u...	View
	1987 Chevrolet Corvette 5.7L Misfire VIN: 1G1YY2184H Hi all! Got a corvette here with 3 dead cylinders (5,6,8). Tried plugs, wires, and a used cap and rotor. Also checked compression, noid light on injectors, and ohmed injectors. Ignition pattern looks fine on scope. All checks within spec. This missfire is alwa...	View
	1995 Chevrolet Lumina APV 3.1L engine VIN: 1GNDU06D4S Hi all, This is the old fashioned 3.1 with distributor. When customer booked in the vehicle, I just figured the intake was leaking as there was very cloudy oil and much coolant foam in the valve cover. Well, this engine has the old fashioned paper intake gaske...	View
	1995 Chevrolet S10 4.3L battery discharges at random VIN: 1GCDT14Z2S this is the bosses moms truck :( and she listens to every barstool bandit out there. this s-10 will start and run 9 out of 10 times it is started but will on occasion fail to start and the battery is totally dead. ( no lights, no dash lights, nothing). she cla...	View
	1996 Chevrolet C1500 Suburban 5.7L Rear heater core VIN: 3GNEC16R8V Rear a/c heater module was removed to replace the expanision valve (pluged due to a blowen compressor). No heat has come out of this unit from that day to this. Seems that coolant will not circulate through the core (air lock). I have very good heat from the f...	View
	1996 Chevrolet Blazer 4.3L Transfer Case VIN: 1GNDT13W7T I am trying to troubleshoot the Electronic Transfer case system on this vehicle. It has the 3 buttons on the dash, not the floor shifter system NV 233. Basically the lights flash on the dash, & the 4WD system doesn't really respond.It came in with a P1875 code...	View
	1998 Chevrolet Express 3500 5.7L distributor gear VIN: 1GCHG39R2W I replaced the lower intake gasket on this van 4000 miles ago for a coolant leak. now the distributor drive gear is worn out. it is worn more on one side than the other. could the intake somehow be installed off center. i cant see how this could happen, but ma...	View
	1998 Chevrolet Express 3500 5.7L distributor gear VIN: 1GCHG39R2W I replaced the lower intake gasket on this van 4000 miles ago for a coolant leak. now the distributor drive gear is worn out. it is worn more on one side than the other. could the intake somehow be installed off center. i cant see how this could happen, but ma...	View
	1999 Chevrolet Malibu 3.1L overflow resevior VIN: 1G1ND52J6X Hi guys, Student's 3.1 that idles all day w/o overheating, but drop it in gear and drive less than 1 block at low to mid speed and we are blowing coolant out the pressurized overflow. I'm leaning towards a head gasket problem. Had classic lower intake manifol...	View
	2000 Chevrolet Impala 3.8L No Start, Cuts out, Stall VIN: 2G1WF55K4Y Vehicle driver complained of intermittant stalling will restart most times. When it stalls the brake indicator, ABS light, and "Battery" on message center comes on. The first time the vehicle was in the shop had Codes P0230 & P0748. Performed flow chart for P... Trouble codes: P0230 (Fuel Pump Control Ckt Problem), P0748 (Press Control Solenoid Elect), C1233 (R/F Wheel Speed Sensor Short/Open)	View
	2003 Chevrolet Silverado 1500 HD LS 6.0L XM Radio VIN: 1GCGK13U93 We replaced the VCM and reprogrammed it with the lastest calibration. Since the install the XM radio will not work. We have tried having the signal sent from XM numerous times as well as reprogramming the radio control module. We also performed a vehicle theft...	View
	1999 GMC Jimmy SL 4.3L blower motor VIN: 1GKDT13W9X car came in with no blower mtr. operation. the lights on the control pannel would not lite (a/c etc.) replaced the blower motor controler still no blower motor. the motor will run on high speed when we ground blk wire from controller to motor. we have no power...	View
	1999 GMC C1500 Sierra SL 5.0L alternator VIN: GZX6D20001 he vehicule comes for voltage variation check computer fuse look good ...change alternator ...everything is good ...one day later came back with the same problem ..last y rempalce it with napa alternator 105 amp...today replace it with 135 amm with the same pr...	View
	1994 Oldsmobile Cutlass Supreme S 3.4L timing belt VIN: 1G3WH55X8R i have a 1994 olds with a broken timing belt twin cam and i have no information as to line up the marks .if possable can some one scan a piture or tell me were they go ,mazda jaguar guy thank for your help	View
	1992 Pontiac Trans Sport 3.8L Starting VIN: 1GMDU0615N We hooked up to our scanner, showed code 42, replaced crank sensor, still would not start. We then replaced ing. module, still no luck. We then replaced the ECM, still nothing!! We then called our Snap-on hot-line, they were of no help. Fuel pressure is OK. HE...	View
	1994 Pontiac Grand Prix SE 3.4L MIL Lamp on VIN: 1G2WJ12X6R Trying to make the peices of this puzzle fit. Customer states these 2 symtoms appeared on the same day. 1)Intermittant MIL (1640) WARM engine only. Poor driveability COLD (cts below 40f) engine only. These symtoms don't happen at the same time. Start cold, poo... Trouble codes: 1640 (quad driver a)	View
	1995 Pontiac Sunfire SE 2.2L Misfire VIN: 1G2JB5241S Car was brought in for external coolant leak at cylinder head (common for this engine), and a misfire at idle. The head was resurfaced and the gasket was replaced. The leak is fixed, but two and a half weeks later, I still cannot find the cause of the miss.I h...	View
	1997 Pontiac Grand Prix SE 3.8L shift interlock system VIN: 1G2WJ52K4V complaint was intermittant shift interlock operation, at times unable to shift out of park. inspect and ck. interlock circuit, verify failed btsi solenoid. inspect and replace assembly. (isold as a complete shifter/solenoid unit. after replacement, worked mult...	View
	1998 Pontiac Bonneville SSE 3.8L supercharger VIN: 1G2HZ521XW I just replaced head gaskets on this car and shortly after starting I noticed a slightly rough sound coming from the supercharger area. I checked the boost guage on the dash and it shows -8 and when you rev the motor it drops down to -10. I know very little ab...	View

Fixes & Summaries for GM

	Fix/Summary	Answers
	1988 Cadillac DeVille 4.5L Poor Idle Quality, Hesitation, Surge, Stall, Misfire, MIL Lamp on VIN: 1G6CD515XJ Thanks to all of you who sent me information. I installed the updated ground stud and bracket that Cadillac offers. There is a TSB on it. It mounts at the rear of the starter. I also ran a ground wire to the distributor base and to the alt. It made no differen...	10
	1994 Cadillac Fleetwood 5.7L starts and stalls VIN: 1G6DW52P2R thanks to the help of james mccloskey from automotive eleltronics of plmouth meeting pa. he show me how to dignost this cadd ,it had troble with the ccm or in this case body computer. thanks scott aidrich, odin01,marc [...] for responing Trouble codes: 46 (pass key).	4
	1994 Cadillac DeVille 4.9L Mechanical VIN: 1G6KD52B2R The vehicle was repaired by removing the transmission and replacing the lower roller clutch assy with the updated parts. Thanks to all who replied. Good day. Perry	16
	1998 Cadillac DeVille 4.6L Blower motor VIN: 1G6KD54Y4W Thanks for all the great replies. I ended up fixing this one with a thought that came to me this afternoon, thinking back to my old sable with auto a/c... No engine heat, no blower motor. This vehicle HAS to be running and see some kind of ECT to operate the b...	9
	1985 Chevrolet G20 Sportvan 5.0L windshield wipers VIN: 1GBEG25H8F thanks to all who replied stating the delay module under the dash was bad. A new delay module took care of the problem. thanks, Chad	24
	1993 Chevrolet G20 Sportvan 5.7L battery VIN: 1GBEG25K2P I would like to thank everyone who responded to my post. The answer to my problem was a new battery. The drain was as many of you said borderline. I also put a higher amperage battery in its place. Thank to all.	14
	1997 Chevrolet K1500 5.0L Transfer case VIN: 1GTEK14M9V Thanks for the 5 replys.Cesar from new york and Duane from michigan hit it on the nose by telling me how to read the codes manualy.This lead to a encoder motor code.On close inspection one screw was broke on motor and allowed water and dirt in and caused a sho...	5
	1998 Chevrolet Tracker 1.6L timing VIN: 2CNBJ136XW sorry it took me soo long to post the fix for this nightmare,but i noticed that the crank gear was chewing into the front cover of the block so i decided to pull the gear off and had to fight the bolt all the way out,come to find out some one had put alot of b...	15
	1998 Chevrolet Blazer 4.3L 4 wd VIN: 1GNDT13WXW thanks to thoes who replied after a long search I found a broken wire under the dash in the harness going to the tccm. thanks, Chad	23
	1999 Chevrolet C1500 Suburban 5.7L Poor Idle Quality, Hesitation, Cuts out, Misfire VIN: 3GNEC16R7X Well I finally managed to fix this headache, I found the intake was leaking a little antifreeze into the PCV system, and also had some poppet valves hanging up. I performed an injector kill test about 5 times and noticed that cylinder #1,#3,#7 rpm's didn't cha...	27
	1999 Chevrolet Blazer 4.3L Charging VIN: 1GNDT13W3X Well, I finally heard from the customer today and he tells me that everything seems to be working fine. Most everyone told me to check the power and grounds, which turned out to be the problem, the leaking positive connection at the battery and/or the connecto...	23
	1994 GMC K2500 Sierra SL 6.5L MIL Lamp on VIN: 1GTGK24F0R well this one is out the door. i need to thank everyone that replied. it did try the manual prosedure for tdc relean about 100 times with no luck .so i sent it to the dealer, they also couldnt get it to relearn. they thought it may be the injection pump. we ha... Trouble codes: 88 (Top dead center offset).	5
	1996 GMC Safari SLE 4.3L Poor Idle Quality, Hesitation, Surge, Cuts out, Stall, Misfire, MIL Lamp on VIN: 1GKDM19W9T car is finally fixed. multiple problems due to someone working on intake and shorting out 5 wires to ground. was unable to find where short was at so ran new wires. 1. both cam signal and ground wires shorted 2. both crank signal and ground wires shorted. afte...	7
	1997 GMC Safari SLE 4.3L Gauges VIN: 1GKDM19W6V Ok, this one is fixed. I should have known that anytime there is a strange electrical problem better start checking grounds, which I did. They all seemed good. So I pulled out the cluster assy and checked at the back of the cluster. On pin out B-13 Black wire ...	9
	1989 Oldsmobile 98 Regency Brougham 3.8L MIL Lamp on, Code 44 VIN: 1G3CW54C3K Thanks for all of your help. The vehicle was fixed by cleaning the EGR valve. IAC counts came back to normal and MIL light has remained off for several hundred miles. Again, thanks to all who replied. Trouble codes: 44 (Lean Exhaust).	14
	1998 Pontiac Grand Prix SE 3.8L 3-2 downshift VIN: 1G2WJ52K9W I have recieved some great information from some members here. Unfortunately on this one something beyond my transmission skills was going on here. I had replaced the pc solenoid due to not passing the amp to pressure test spec sheet available on alldata. Also...	7
	1999 Pontiac Sunfire SE 2.4L Excessive Emissions, Poor Idle Quality, Misfire, MIL Lamp on VIN: 1G2JB52T3X i would like to thanks everyone who responded!!! according to the state of ct. dmv the selling dealer is required to get any vehicle sold to pass emissions. therefore this vehicle has been sent back to selling dealer, as per customer request and ct dmv. th... Trouble codes: 0300 (random cylinder misfire).	12
	1996 Saturn SL1 1.9L Excessive Emissions VIN: 1G8ZH5282T Thanks to all that responded. The 'root' problem was the O2 sensor. Saw a slop job on a no name O2 and replaced it with a 'name' aftermarket. Bad move. GO OEM on this one. The aftermarkets have worked well for me dozons of times on GM's but not this SATURN (GM...	9

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