GM Automotive Technicians Technical Discussion and Fixes for Jan 16, 2008

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	Help Request	Answers
	1993 Buick Regal 3.1L Surge, Stall VIN: 2G4WB54T5P Test drove, stalls and surges at idle at times. Idle relearn - highway & city - A/C on & off - Vehilce fine at times then cannot find idle at stops. Cleaned IAC - Checked for vacuum leaks & Monitored pids, Ok	View
	1995 Buick Riviera 3.8L speedometer and trans VIN: 1G4GD2214S Customer brought vehicle in with no speedometer and trans acting strange. Confirmed that the speedometer doesn't work and the trans appears to only have 2nd and 3rd. Following flow chart from Mitchell I checked the speed sensor and wiring, all seemed fine and ...	View
	2001 Buick LeSabre Custom 3.8L MIL Lamp on VIN: 1G4HP54K91 cah has to be out a week or so before check engine light comes on. Trouble codes: 440 (evap leak), 442 (452 - gsa cap), 452 (gsa cap)	View
	1994 Cadillac DeVille Concours 4.6L harsh engagemant VIN: 1G6KF52Y3R greetings to all we have this caddy that has a very harsh engagemant when going from park to drive also has acode 76 force motor problem,28 trans pressure switch manifold problem. i ohmed out the solenoid and that seems fine i spoke to my transmission rebuilde...	View
	2000 Cadillac Seville SLS 4.6L Air bags VIN: 1G6KS54Y4Y After crash replaced all Air bag compnents with used parts. All codes gone except B0051 (Deployment Command) All my info says it's a "latched" code and cannot be cleared. Do I need to have this thing "reflashed" to clear this code, or is there something I'm d...	View
	2000 Cadillac DeVille DHS 4.6L abs VIN: 1G6KE57Y1Y Car came in with brake light, traction control light, abs light and check engine light on. Engine light was a lean code. Replace upper intake gasket and boot and fixed problem. Then comes the abs,brake traction lights. codes were as follow U1040, P1571, P1644 ...	View
	1992 Chevrolet S10 Blazer Sport 4.3L Hesitation, Cuts out, Stall VIN: 1GNCT18W1N Vehicle tends to run ok cold in open loop with integrator & block learn readings at approx 128. Shortly thereafter as the O2 reads a consistent 9 mv the integrator & block learn bottom to approx 80. The instant vehicle hits closed loop it sputters & nearly die...	View
	1996 Chevrolet Tahoe LS 5.7L crank no start VIN: 1GNEK13R3T car came on hook. check all vitals. has spark, 60 psi fuel pressure. check all relevant connections-good.removed spark plugs they were fouled. replace with new spark plugs. check for injector pulse .good. any ideas guys.	View
	1996 Chevrolet Cavalier 2.2L Starting VIN: 1G1JC1249T we installed a used moter every thing looks be ok, but thef light stay on all the and the wont start	View
	1998 Chevrolet Malibu 2.4L Water outlet VIN: 1G1ND52T7W This is the fourth time in a year that this car has come in for a coolant leak. It has been the water outlet housing each time. It rots or disintegrates at the lip for the O-ring. I have tried aftermarket and oem pieces and it goes about three to four months a...	View
	2000 Chevrolet Blazer LS 4.3L Differential Engagement VIN: 1GNDT13W8Y Truck is equipped with 2-speed selectable 4wd, electronically actuated via switch assembly on the dash. This message is as much about theory of operation as anything. What does the switch in the front axle actually do? With the harness unplugged, pressing the ...	View
	2000 Chevrolet Express 3500 6.5L No Start VIN: 1GCHG39F9Y installed rebuilt engine, customer unable to pay for 6 months. finally got money together so i said i would do one more checkover.the van dies on the shop floor,unable to restart.no codes but in data stream get ghost hits of crank and cam misses. pump set and ...	View
	2000 Chevrolet Blazer LS 4.3L service 4x4 light VIN: 1GNDT13WXY this one is driving me crazy,belongs to family.When you drive it approx. 3 miles the 'service 4x4' light luminates on dash.Its not in four wheel drive either.I have replaced the switch already and the light still comes on.It goes into 4 wheel drive low and hig...	View
	2001 Chevrolet Express 1500 5.0L No Start i am trying to help out a friend at another shop.he has a 01 gmc 1500 van with a 5.0l.when the vehicle is cold it will not start unless fuel is sprayed into throttle body then it starts and runs fine.if you shut it off it will restart but if you let it sit for...	View
	2002 Chevrolet Malibu 3.1L horn VIN: 1G1ND52J92 customer came in stating that sence it is colder out side ( about the last week or so ) the horn will chirp and the radio will also make a biping sound durin driving ( but not all the time ) i scanned the body mod and found no codes at all. you can have the ke...	View
	2002 Chevrolet Trailblazer LS 4.2L t/case ECU VIN: 1GDNT13S62 When we first started looking into problem we were not able to get data at all. We followed mitchells diagnostic no code testing and found good powers and grounds and also scoped the data from body controler to transfer case ecu and found data stream coming fr...	View
	2003 Chevrolet Impala 3.4L rack, column VIN: 2G1WF52E83 There is a slight squeal noise when the steerig wheel is turned, engine off or on. It sounds like a shaft turning in a dry bushing. The sound is coming from the pinion seal area of the rack. There was no squeal when the steering wheel was turned with coupler s...	View
	2006 Chevrolet Trailblazer LT 4.2L Starting VIN: 1GNDT13SX6 have this one that we were looking at for front wiper inop, this morning putting the key in the ignition STARTER WILL ENGAGE when only having the key in the on position. Just wondering if anyone has run into this before. key is definitely not in starter positi...	View
	1995 GMC C3500 Sierra SLE 6.5L Cuts out, Stall VIN: 1GDKC34F4S truck came in with a intermittant stall when put in to gear. the problem never happened for me. the truck left and returned a few weeks later. this time i witnessed the problem. it would be hard to start if you could get it to start then cut off i looked at th...	View
	2004 GMC Envoy XL SLE 4.2L Poor Idle Quality Every time suv is started idle speed jumps to 2,100 rpm's. it takes about 1 & 1/2 minutes for idle to come down to 900. after it is driven at highway speeds and slowing down or pulling up to stop idle is at 2,100 rpm's again & slowly comes back down.	View
	1993 Oldsmobile Cutlass Supreme 3.1L Surge VIN: 1G3WH51TXP Customer complaint is rpm surges under decel - no brake or thottle. Occasionally stalls under same circumstances. I found the vacuum line disconnected at the transmission throttle modulator. Hooked it back up with no difference. Also tried disconnecting EGR va...	View
	1995 Pontiac Trans Sport 3.8L No Start VIN: 1GMDVO6L9S ran o.k. but ck. pulley rattle replaced than no start switch back to old still no start space out ck sensor,and replaced, tried ign module, ign switch,coils,have power to ck. and cam sensors have scope patterns for both at ign mod.- tickle fuel output-injecter...	View
	2002 Pontiac Sunfire SE 2.2L bcm,abs,anti theft VIN: 1G2JB52472 I have a strange problem with a 2002 sunfire,with headlights on and blower on high the guages drop to zero,abs,anti theft and service wrench lights come on.Codes in pcm p1626,u1040,u1064,u1301,codes in bcm b2600,u1000,u1016,u1088,u1096,u1128,bcm voltage with s...	View
	2002 Pontiac Montana 3.4L power sliding door VIN: 1GMDU03E42 Good Afternoon we are having trouble locating information on re initialization proceedure any help would appreciated.	View
	2004 Pontiac Montana 3.4L Heater VIN: 1GMDX13E74 This is a strange one. The vehicle is running at proper temp, all heat controls seem to be working fine. If you have this on full hot, you get nice hot air out floor vents, but the air comming from the defroster vent is cold. Switched to full floor, and heat i...	View
	2005 Pontiac Vibe 1.8L MIL Lamp on VIN: 5Y2SL63885 Cleaned the MAF 9 months ago for lean code. Car came back in December, replaced MAF then, car is back today. I am thinking O2 sensor, any other ideas? Can't find any obvious vacuum/intake gasket leaks. I searched in the Toyota Matrix section also. The freeze f... Trouble codes: P0171 (System too lean)	View

Fixes & Summaries for GM

	Fix/Summary	Answers
	1994 Buick Park Avenue 3.8L No Start, Stall VIN: 1G4CW52L1R Thanks to all techs who offered their tips about what to look for, but especially to those who said to check the ground buss located under the driver's carpet! When we peeled up the carpet we found a hole in the floor and the buss was severely corroded. A vol...	14
	1994 Buick Park Avenue 3.8L No Start, Cuts out, Stall VIN: 1G4CW52L6R Upon closer inspection of the wires going to the cam sensor[after cleaning grease from wires] I found 2 out of the three wires had a bare spot rubbed through the insulation shorting to ground causing the intermittent no start or die out condition.When these wi... Trouble codes: 341 (intermittent signal cam sensor), 341 (intermittent signal cam sensor), 342 (cam sensor failure).	12
	1995 Chevrolet Corsica 3.1L No Start, Stall VIN: 1G1LD55M6S well customer does not have money for repair I am confident that new injectors will fix it but never did get any test results that showed bad injectors. how ever the tech 2 says injector fault after cranking and when plugging in a different set from a used car...	28
	1999 Chevrolet Tahoe LS 5.7L Misfire, MIL Lamp on VIN: 1GNEK13R9X Hi all tecs who had a thought on this repeated cap/rotor failure, and thank you very much. The Tahoe returned several days ago, at our request, and we opened up removed dist cap and inspected, about 500 miles on new cap, rotor and plugs. Using information that... Trouble codes: P0300 (Random misfire).	37
	2000 Chevrolet Express 3500 5.7L Axle bearing VIN: 1GCHG39R52 Thank you to all who responded to my issue. The customer showed up at my shop the day after I sent out this post (she had not paid the original bill yet) & gave me a certified cheque for what she owed me minus her costs for fixing the axle bearing. After a s...	31
	2004 Chevrolet Aveo 1.6L client gets shock every time she leaves the car VIN: KL1TD62644 Thank you for your help. The fabric sheet between the springs and cushion of drivers seat and spraying scotch guard on seat has reduced the 'shock's considerably. Client is very happy. Thanks	17
	2004 Chevrolet Silverado 1500 5.3L oil guage VIN: 2GCEC19T24 Guys, I took your information and gave it to the customer. He will be heading to the dealer on this one. I used to work at a Chevy Dealer 3 years ago and remember seeing these come into the shop but since I wasn't a drivability tech I wouldn't have to deal ...	5
	1999 GMC Savana 2500 5.0L 3-4 shift VIN: 1GTFG29M8X thanks to all who replied. most of the replies still leaned toward the trans, so i pulled it out and put it in a known good working van. shifted perfect. this is one of the advantages of doing fleet repairs, there is usally more of the same van. this ended the...	8
	1992 Oldsmobile 88 Royale 3.8L Excessive Emissions, Poor Idle Quality, Stall, Misfire VIN: 1G3HN53L6N Thanks to all, I received suggestions to check for vacuum leaks,a good tip on checking for plugged injectors( unplug all injectors , pressurize fuel system,activate each individual injector and watch for pressure drop on a gauge)thanks Brian. This morning we p...	6
	2000 Oldsmobile Intrigue GL 3.5L MIL Lamp on VIN: 1G3WS52H7Y A rebuilt MAF was the fix for this one. The ignition switch was also bad, not supplying enough voltage to A/C and Cruise Control circuits.	6
	2001 Oldsmobile Bravada 4.3L Battery VIN: 1GHDT13W71 O.K. I stand corrected! I miss read a TSB, thinking that a 70 to 120 MiliAmp draw was normal for this vehicle. Thanks to Chester from North Carolina I now know A 50 Miliamp draw is the max for G.M. vehicles. With that info I did another draw test and found tha...	5

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