GM Automotive Technicians Technical Discussion and Fixes for Dec 15, 2011 - iATN (Members Only)

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Open Help Requests for GM

	Help Request	Answers
	1999 Chevrolet K1500 LS 5.7L Stall VIN: 1GNFK16R2X This suburban is kicking our butts. it stalls intermitatly. it can run fine for four hours and next time 10 mins in it has stalled 7 times. only stalls at idle. seems to me like a momentary loss of ignition.Has New fuel pump module, has new injector spider ass...	View
	1999 Chevrolet C2500 7.4L Poor Idle Quality, Poor Fuel Economy VIN: 1GCGC23J0X i dont use the truck much when i do i will treavel about6 miles to home and when i get 1mile from home at stops it will start to flood out and black smoke out the tail pipe and want to die. i have even had the fuel regulator vacume hose disconected to see if i... Trouble codes: P00, 300 (mis fire), P0174	View
	2000 Chevrolet Malibu 3.1L Stall VIN: 1G1ND52J6Y Hello techs. This one has me stumped. Car came in with a no start. I was able to start it but it would stall and backfire. I unplugged the mass air flow sensor to see if it would improve things. I did a basic charging and starting test. The battery failed so ...	View
	2004 Chevrolet Colorado LS 3.5L No Start VIN: 1GCDT14684 Car was towed here, no start. Positive battery cable was off. Hooked up battery, no crank. Had several codes stored in memory in the BCM, B0529, B0534, both turn signal codes, B1372 device ign 1 circuit low. B1382 device accessory circuit, B1420 Device voltage... Trouble codes: B2958 (Security system sensor data circuit high)	View
	2005 Chevrolet Impala 3.4L no heat VIN: 2G1WF52E05 car has no heat even after car comes to 180 deg.temp blows out ice cold, the temp gauge bounces from 180 to 210 but never over heats.	View
	2006 Chevrolet Trailblazer LT 4.2L No Start VIN: 1GNDT13S46 2006 trailblazer 4.2 was towed to the shop ,it will crank but not start,the blazer was flooded changed plugs ,immediately flooded when trying to start,no spark or very little with spark tester,scanner showes rpm when cranking ,changed crank sensor to be sure s...	View
	2007 Chevrolet Trailblazer LT 4.2L Cold Star Up VIN: 1GNDT13S77 Thanks in advance. getting sharp whine noise on start up from trans. will last about 5 seconds in park then will continue if engine is reved up in park neutral reverse or drive for about 5 min. then all is fine for unless you shut it off for about 3 hours. sou...	View
	2000 GMC Yukon SLT 5.3L Hesitation VIN: 1GKEK13T0Y This yukon has an intermitant low power condition.feels like its starving for fuel.no dtcs ,fuel pump replaced with aftermarket pump and maf sensor replaced also.on cold start i noticed iat reading going from -35 to 350 and st and lt fuel trims jumping from +4...	View
	2003 Pontiac Grand Am GT 3.4L No Start VIN: 1G2NV52EX3 Ok this thing is kickin my butt, cold koeo injectors will pulse when scratched with either a 5 volt reference or test light at purple and white wire at the ign module. has good signal to pcm from ign module when cranking injectors still won't pulse. No BCM cod...	View
	2008 Saturn Vue XE 2.4L theft deterrent VIN: 3GSCL33P88 Another shop put a used theft deterrent module in and took it to us to get programed.and that where we got in trouble! could not get it programed.got a new module and the samething,with service code B3031.when you get to the tranfer Data screen the hour glass ...	View

Fixes & Summaries for GM

	Fix/Summary	Answers
	2003 Buick Rendezvous CX 3.4L Hesitation, Cuts out VIN: 3G5DA03E73 Sorry for the late reply. Looks like the problem was in the ckp sensor at the back of the engine. I ended up scoping it and the signal wasn't as nice as it should be. Replaced it and all was good. I dont understand how that explains the alternator light though...	21
	2006 Buick Rendezvous CXL 3.5L Rear brakes stay applied VIN: 3G5DA03L56 Well my guy did this brake job he has little experience,although I missed it too. The customer wanted cheap brake rotors so we installed Aimco rotors.The rotors are not built to spec properly causing the rear brakes to lock on. Installed Napa rotors and all wa...	5
	1998 Chevrolet Blazer 4.3L MIL Lamp on VIN: 1GNCT18W4W Our neighboring dealership looked at it and came back with "faulty oxygen sensor". We had already replaced it twice with a Denso product and had voltage changed from the sensor. We replaced it with another brand (Delco) and the problem was corrected instantl... Trouble codes: P0134 (Insuffecient activity bank 1 sensor 1 - O2).	11
	2000 Chevrolet Suburban 1500 LT 5.3L Pcm VIN: 3GNFK16T2Y THANKS TO ALL THAT RESPONDED TO MY REQUEST.WE HAVE DON [...] FURTHER TESTING ON OUR OWN TIME BUT CAME UP DRY. CUSTOMER HAS DECLINED FURTHER DIAGNOSTICS.I CANT THANK IATN ENOUGH, THIS IS A GREAT DIAGNOSTIC TOOL.	9
	2002 Chevrolet Silverado 1500 4.8L Cuts out, Misfire, MIL Lamp on VIN: 1GCEC19V02 Thanks for all the replies. The vehicle was repaired with the advice from another IATN member, Mike Hall. Fuel phase separation was the issue. With the ethanol content being so high today, do not look past the fuel with driveability issues. Trouble codes: P0300, P0171, P0174.	13
	2005 Chevrolet Colorado Z85 3.5L ATC-transfer case shifting VIN: 1GCDT19625 thanks to all who replied. I checked everyone's suggestions and finally decided to try replacing the front actuator which cured the problem. It was interesting that it worked intermittently how it did. thanks	4
	2005 Chevrolet Trailblazer LS 4.2L Poor Idle Quality, Cuts out, Misfire, MIL Lamp on VIN: 1GNDT13S15 OK here goes: First, thank you very much for your time and advice! Second, the vehicle's condition has changed/improved, but is not yet ready to return to the customer. What we did was replace the cam sprocket/phaser assembly. It was, in fact, stuck toward... Trouble codes: P0017 (Ckp/exhaust cmp correlation).	9
	2006 Chevrolet Colorado LT 2.8L Turn Signals VIN: 1GCCS14896 Narowed it down to the body control module.Customer did not have the money to Repair at this time and is his 3rd vehicle.Thanks for all that replied all the input was very helpful.	7
	2003 GMC Sierra 2500 HD SLE 6.6L wastegate VIN: 1GTHK23103 The idle fluctuation was very subtle and not a major concern of the customer. We remedied his real concerns which were excessive smoke and "Check Engine" warning light on. We did not have authorization to dig into the wastegate issue which was causing a slight...	5
	2007 GMC Yukon XL 1500 Denali 6.2L Suspension VIN: 1GKFK668X7 Thanks for everone's help, however , we timed out on this denali. we swapped wheel bearings from side to side with no luck. we checked steering shaft and packed with grease, still no change. noise really doesn't feel or sound like a steering shaft noise. tried...	11

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