GM Automotive Technicians Technical Discussion and Fixes for Dec 9, 2008

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Open Help Requests for GM

	Help Request	Answers
	1987 Buick Regal GNX 3.8L Poor Idle Quality, Hesitation, Stall VIN: 1G4GJ117XH Cold start . Starts and stalls. Cold hesitation. Pinch off return line and get pressure up in the 50 to 60 psi range and hesitation and stall are gone . Idle is horrible at 50psi. Ohm check coil pack , Block learn / intergrator 128 131 once warm. compression g...	View
	1992 Buick LeSabre Custom 3.8L Brake Lines VIN: 1GHR5314NH I'm looking for a diagram of the output ports from the ABS unit. When this car 1st came in someone else had done some brake work, and only one would grab. Real weak pedal, some of the problem was corrected with the Master that was leaking. Now it has a good fi...	View
	2002 Buick Century Custom 3.1L Misfire VIN: 2G4WS52J12 Customer came in for several problems. She had complaned for some time about it losing coolant and the transmission would shift hard at times. finaley we got a trouble code P1811 max adapt and long shift to set. she said that when she was passing a car on the ... Trouble codes: P1811	View
	2005 Buick LeSabre Custom 3.8L Internal Mode Switch VIN: 1G4HP54K75 Customer was out of town when they experienced a no-crank, no start. They had it towed to a nearby dealer, but it restarted when the key was turned. ("Probably needs a starter", they were told) They made it home with intermittant problems. Eventually it restar...	View
	1994 Cadillac DeVille 4.9L MIL Lamp on VIN: 1G6KD52B3R Vehicle came in this mourning, complaint of jerking and running rough wih check engine light on. Pulled codes 26 codes from memory, cleared. After clearing 16 codes return immediatedly, 80, 79, 78, 77, 105, 102, 114, 112, 110, 128, 126, & 125. I checked batter...	View
	1997 Cadillac DeVille 4.6L battery VIN: 1G6KD54Y7V I have a 1997 cadillac deville with a current draw problem. Customer says it will drain the battery over a couple of days. Performed current draw test and found 1.4 amp draw. traced the complaint to two possible problems. #1 the radio will pull about 900ma for...	View
	2001 Cadillac Catera 3.0L Poor Idle Quality VIN: W06VR54R41 Hello to all, Need some help on this Catera. Vehicle came in po171 po174 po302 po303 po305. and a high idle problem vehicle had high idle prior to misfire replaced plugs and coil packs misfire gone still idles around 1100-1200 checked fuel pressure @ 30 PSI KO... Trouble codes: P0171, P0174	View
	1991 Chevrolet Lumina Euro 3.1L No Start VIN: 2G1WN54T8M HELP!!! This car is kicking my butt! Car came in sputtering and running rough...tested injectors and found three bad...no suprise there! Replaced injectors and sent customer on their merry way. Car came back two days later on the hook with no start condition. ...	View
	1995 Chevrolet K1500 5.7L Hesitation, Cuts out VIN: 1GTEK19K2S We inherited this problem child from another shop. The truck runs fine at idle and up to 2000 rpm and will then cut out with anything more than 40% throttle. The previous shop replaced fuel pump and filter thinking it was starving for fuel. My first impression...	View
	1998 Chevrolet S10 LS 2.2L No Start, Cuts out VIN: 1GCCS1944W vehicle will crank but not start sometimes. will loose spark for only short time while cranking but will start after 3 or 4 revolutions. vehicle will then act like it is fluided. then after cranking for awhile it will start . then it will be at least 8 to 10 t...	View
	2000 Chevrolet Tracker 2.0L Front Axle VIN: 2CNBJ13C4Y Everything works the way it should except there is no signal to the vacuum pump mounted on the inside front bumper. I have checked all the fuses. I am not sure if it is controlled by the pcm or not.	View
	2000 Chevrolet S10 2.2L Misfire VIN: 1GCEC1944Y Hello IATN techs! Having a little trouble with this S10. Customer complaint was a severe hesitation when you accelerate to WOT. It also randomly misses at times, never more than once or twice. He wanted a tune-up so we replaced plugs, wires, and even tried two... Trouble codes: P0200 (Injector Control Circuit), P0303 (Misfire Cylinder 3)	View
	2001 Chevrolet Express 2500 4.3L Poor Idle Quality, Stall VIN: 1GTGG29W81 van has intermittent idle issues that started a while back. We noticed it when the intake manifold started to leak. It seamed that the ais motor was not working at that time so we replaced it. we test drove after the repair and shipped it, thinking it was all ...	View
	2002 Chevrolet Tahoe LS 5.3L MIL Lamp on VIN: 1GNEK13Z32 this truck came in with miss fire codes, we did a tune up first(Could actually see the spark plug wires arching), customer came back a week later with a new missfire, tested convertor for excessive back pressure - OK . tested fuel pressure OK. Located #3 injec... Trouble codes: P0171, P0174	View
	2002 Chevrolet Trailblazer LS 4.2L MIL Lamp on VIN: 1GNDT13S82 Vehicle came in to my shop do to not passing emmision test,I scanned it and it showed thre [...],P0172 and P0340,I did order the cam sensor and did not install it yet,but I'm testing the fuel trims and can not figure out why it is lean and rich at the sam... Trouble codes: P0171 (system lean bank 1), P0172 (system rich bank 1), P0340 (cam sensor sygnal problem)	View
	2003 Chevrolet Tahoe LT 5.3L tach light VIN: 1GNEC13Z83 Has anyone fixed a inop tach light? It looks like a circuit board issue. Does anyone think by just removing the instrument panel and putting it back could cause it. The customer says we damaged it.I seriously dought it. Please advise. Thank you Larry [...]	View
	1991 GMC C3500 HD 6.2L converter Worked great for 2 week,s Is it posible crank runout would cause this problem ? [tras, presure ok] or falty conv, Any input to solve this problem would be welcome,, Thanx Wes..	View
	1999 GMC Sierra 1500 SL 5.3L instrument cluster VIN: 1GTEK19TXX this truck came in with odometer,high beam indicator,message center,seat belt light,charge light,not working.turn signals and service engine light only lights that work.scan tool will communicate with bcm,no codes in the bcm.engine codes U1064 which says loss ...	View
	1994 Pontiac Grand Prix SE 3.1L heat VIN: 1G2WJ12M6R The vehicle came in with a coolant leak and no heat. After pulling in bay I filled system with coolant and started. Of course leak was from around water pump shaft. Also the coolant was very dirty and only at -15. After replacing water pump and flushing coolin...	View
	2000 Pontiac Bonneville SE 3.8L locks, windows,mirrors VIN: 1G2HX54K8Y I'm testing the simple bus interface from the driver door moudule to the other doors. I'm trying to decide if I have just one or two problems. First I have battery voltage on the tan and white communication wire which tells me I have current bleeding over and ...	View
	2003 Pontiac Grand Prix SE 3.1L ign lock cyl ctrl actuator VIN: 1G2WK52J83 This vehicle came in because the customer said she cannot get her ignition lock cylinder to return to the "OFF" position when turning off her car, running her battery down overnight. She brought in her own ignition lock cylinder, I recoded it to her key, and ...	View
	2006 Pontiac Grand Prix 3.8L Poor Idle Quality, Hesitation, Surge, Cuts out, Stall, MIL Lamp on VIN: 2G2WP55206 The car came in with app sensor codes I went through the test all wiring tests ok it has a 5v ref like it should but was setting the codes. According to the test it said to replace the app sensor so I did. It ran ok for a few minutes and than started setting t... Trouble codes: P1125, P2138	View

Fixes & Summaries for GM

	Fix/Summary	Answers
	1998 Buick Park Avenue 3.8L warning lights VIN: 1G4CW52K7W This vehicle did not have the 2 positive battery cables at the battery that many said to check. I did check the grounds and they were all good. The connections at the instrument cluster were tight. I told the customer that it was probably the instrument clu...	14
	2001 Buick Regal LS 3.8L Hesitation, Cuts out VIN: 2G4WB55K71 unbolted exhaust system and drove vehicle had plenty of power replaced the cat and muffler and no more issue.thanks to all that helped.	13
	1998 Cadillac DeVille Concours 4.6L Radio, windows VIN: 1G6KF5498W A recieved a few responses. Ignition switch, door switchs or possilby in the BCM. I think the problem is in the BCM, due to customer finances he opted to have me install a battery disconnect switch inside the vehicle. Problem solved	5
	1995 Chevrolet K2500 Cheyenne 6.5L Power Streering VIN: 2GCFK29S2S First of all I would like to thank all that took time to respond to my post. We replaced the Power Steering box again, this time used heavy duty application (8600GVW) even though truck calls for 7200GVW box. ACdelco techline pointed us in the right direction(o...	7
	1997 Chevrolet Venture 3.4L Timing cover VIN: 1GNDU06E2V Thank you so much. I was overwhelmed with mails from all of you. The job can be done without oil pan removal. It was a very straight forward job, no surpises at all. All being said and done the job only took a few hours. You guys are great.Thanks	21
	2002 Chevrolet Trailblazer LS 4.2L using motor oil VIN: 1GNDT13S02 We haven't fixed this yet- Customer is still pondering his options.I agreed with Kent- we should try some GM Top engine cleaner soaking the rings for a few days if they are stuck. The engine was very dry externally. Larry suggested that the PCV system may be r...	9
	2004 Chevrolet Cavalier 2.2L Day time running light VIN: 1G1JC52F74 Thank you all for the help you've given us, many good info where pass... Most of you point at the splice in the wiring behind the left head light, in our case, it check ok. We did push farther and find a resistor behind the bumper cover under the right head ...	14
	2006 Chevrolet Colorado LT 2.8L Cuts out, Stall, Misfire, MIL Lamp on VIN: 1GCCS14896 Sorry I didn't post sooner. Replaced the cam actuator solenoid. had some debris and all screens but that took care of it. Thanks to all for your responces Trouble codes: P0014, P0106, P0300.	5
	2007 Chevrolet Equinox LT 3.4L ABS Motor VIN: 2CNDL63F77 Hello all, the noisy Traction control was fixed by replacing the ABS motor and valve assembly. After the repair we drove the vehicle and the regular noise from the motor valve assy. was heard. We did however still have a loud ABS noise when locking up the brak...	3
	1998 GMC K1500 Sierra SL 5.7L Brakes VIN: 2GTEK19R6W Found that the parts store sold me the wrong master cylinder. Replaced with OEM matched to VIN number. Works fine.	16
	1998 GMC Savana 3500 6.5L Cuts out, Stall VIN: 1GTHG35F1W The injection driver module was the fix. The GR. wire at the module had a square wave form, but, the red wire did not have wave form. Trouble codes: P0251 (injection pump cam system).	3
	2001 GMC Savana 2500 5.0L Excessive Emissions, Misfire, MIL Lamp on VIN: 1GTFG25M11 THERE WAS A PROBLEM WITH COMPUTER HASNESS GOES TO THE FUEL INJECTORS.REPLACED THE ELECTRICAL PLUG AND THAT WAS IT.THANKS FOR THE REPLIES. Trouble codes: P0300, P0200.	4
	2000 Oldsmobile Bravada 4.3L transfer case VIN: 1GHDT13W5Y This truck has been gone for 3 weeks and the customer says it is working fine. I replaced the transfer case control module to fix the problem. I monitored the front and rear speed sensors with a dual channel lab scope and the frequency and amplitude of the A...	4
	1994 Pontiac Grand Am SE 2.3L Turn Signals VIN: 1G2NE5531R I would like to thank everyone for taking time to try and help me. This flasher was dead as could be, so even when turning on, there was no click or nothing. Talked to the local GM Dealer, and even they couldn't tell me where this was located. On this particul...	9
	1999 Saturn SL2 1.9L Hesitation, Surge VIN: 1G8ZK5275X Thank you for your help I definitely went brain dead on this one. As you all suspected backpressure from the exhaust was causing it. I asked a new tech to check the catalytic converters for me and since he had worked as a diagnostic Tech for Toyota dealership ...	7
	2003 Saturn Vue 3.0L shift lock VIN: 5GZCZ53B03 Thank's for the replies. I ordered a new shift lock solenoid from Saturn and I think this would have fixed it. Before the part came in the customer traded it on anew Audi. The circuit looks simple enough. What I planned on doing is checking the resistance of t...	4

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