GM Automotive Technicians Technical Discussion and Fixes for Feb 25, 2009 - iATN (Members Only)

×

Join Now

Prev	Professional Automotive Repair Technical Discussions for February 25, 2009 International Automotive Technicians' Network (iATN) - Members Only	Next
(Also Available: All, Asian, Chrysler, European, Ford, GM.)
Vehicle Owners: If you are seeking an automotive repair professional to service your vehicle, visit the iATN Repair Shop Finder.

Open Help Requests for GM

	Help Request	Answers
	1995 Buick LeSabre Custom 3.8L No Start VIN: 1G4HP52195 hello techs,this one gat me.this car came in with a loud backfiring problem.the car would start and run for a minite or so and then it would start missing and die with a loud backfire.I try to have the code read but my scanner wont link to the pcm.found out th...	View
	2005 Checker Avalanche 5.3L Excessive Emissions, Poor Idle Quality, Hesitation, Misfire, Poor Fuel Economy, MIL Lamp on VIN: 3GNEK12ZX5 This vehicle only runs bad after hard acceleration.The map voltage goes drops to -0.60 volts.I removed the map to inspect and it was soaked with oil.i cleaned the oil off and voltage is normal around 1 volt at idle. redrove vehicle runs fine until you accelera... Trouble codes: P0151, P0174, P0300	View
	1995 Chevrolet C3500 6.5L No Start No start, Fuel bowl empty, All fuses good No codes! I even bugged the truck and rechecked for codes to make sure it was not a communication problem, cleared my created codes.I Removed and inspected fuel pump relay and I have power on the "30" pin, none anywher...	View
	1997 Chevrolet K1500 Cheyenne 5.7L Cuts out, Stall, MIL Lamp on VIN: 1GCEK19R6V i have replaced the coil,ingnition module,crank senser now i going to look at the computer on this truck. what the problem is when it is hot the truck cut out when i put a load on it. the codes then set.when it is cold it runs great. any help would be great. Trouble codes: 339 (crank senser intermittently), 341 (cam senser out of range)	View
	2000 Chevrolet Tahoe 5.3L Speedometer VIN: 1GNEC13TYR Scoped vss circuit have good pattern, so replaced cluster, and still no speedo are odometer and still want shift out of second gear, can anyone please help, Thanks in adavance	View
	2000 Chevrolet Tahoe LT 5.3L Poor Idle Quality, Misfire VIN: 1GNEK13T3Y truck came in had p0304 replaced #4 coil no change then done fuel injection clean still same. so done crank relearn no change cleared eng light it now has p0300 but check eng light not on misfire count high on cyl 4 little on cyl 3. does not appear to be vacum...	View
	2000 Chevrolet Impala LS 3.8L No Start VIN: 2G1WH55K8Y Have tested crank sensor and cam sensor at ignition module all 3 signals are as expected and seem to be fine.We have injector pulse but no spark on any of the 3 coils... take off the coils and check the pins on module and you have 12 v on supply but module not...	View
	2001 Chevrolet work horse 6.5L Electronic VIN: 5B4KP42Y51 hi guys i have a 2001 workhorse the transmission do s not shift into 4th gear . no codes i could shift with the tech2 into 4th gear .the guy change the trans and the ecm. the only thing i see is the tft temp is 120 to 130 .the trans id is 4l80e . alldata do no...	View
	2001 Chevrolet Impala LS 3.8L lights VIN: 2G1WH55K71 hello there gm techs,i have this impala that came in on a hook..no start...dead battery,easy enough right?..replaced battery,alternator inop...replaced alternator...5 days later customer called to say the abs lite,the tcs lite,the cluster lights and headlights...	View
	2001 Chevrolet Impala LS 3.8L No Start VIN: 2G1WH55KX1 this car came into the shop with a intermitten no start situation. had it to happen, when turning the key to the start position will not engage the starter. went to alldata and found a crank relay, pulled up the wiring diagham and found that it takes two power...	View
	2002 Chevrolet Monte Carlo SS 3.8L security light VIN: 2G1WX15K22 Good afternoon. We have a 2002 Monte Carlo that the customer states the security light came on one time at start up. (NOTE: We replaced BCM 1 week ago.) Scanned BCM, B1440, B2958, B2964. Passlock sensor voltage 3.57. Vehicle is equipped with a remote start. I ... Trouble codes: B1440 (Power mode mismatch), B2958 (Passlock), B2964 (Key in Ignition)	View
	2005 Chevrolet Trailblazer LS 4.2L Speedometer VIN: 1GNDT13S15 The customer complained that after driving the speedometer will all of a sudden go to zero. No reading. We checked the sensor and resistance was zero. The sensor was replaced with a after market sensor. The problem still exists.	View
	2002 Pontiac Grand Prix GT 3.8L LF sensor code set VIN: 1G2WP52K32 Car came in with ABS & trac light on part time. Code C0035 set for LF circut malf. wiring shows no damage. Car has to move just a few feet to set code but scan tool shows wheel speed working the same on all four corners. Also and maybe not related the informat...	View

Fixes & Summaries for GM

	Fix/Summary	Answers
	2000 Cadillac DeVille 4.6L vehicle theft system VIN: 1G6KD54Y7Y Thanks to all that replied.Matthew found a GM bulletin on what I was having trouble with and it was right on. On Caddy devilles(may include others) built before vin breakpoint [...] were built with a plastic key tumbler housing and that the new vtd module c...	6
	1994 Chevrolet Camaro 3.4L Cooling Systems VIN: 2G1FP22S4R Hello everyone that has responded to my request. Thank you for all of your replies I came in this morning pulled the upper intake plenum and valve covers. I could see coolant sitting in the valve area on the right side. Proceded to connect all hoses and fill w...	13
	1998 Chevrolet Malibu LS 3.1L Fuel Gauge VIN: 1G1NE52M0W Thanks to all that replied,but all i needed was to know if anyone knew why this happens only in GM vehicles. Not how to fix symptom. Thanks to all that replied again, we are the best!!	36
	2001 Chevrolet Tahoe 5.3L Mirrors VIN: 1GNEC13T11 Thanks for the help and responses. The diagnostic chart that Chris gave me really helped a lot. After going through the steps, it turned out the Mirror Switch was bad. Put in a new one and everything works fine. Thanks again!	4
	2005 Chevrolet Colorado Sport 3.5L driver window, power locks VIN: 1GDT136458 Hi, I beleive we can put this one to rest. I talked to the customer today and everything is working fine. I am suspecting that all I needed to do was take the vehicle for a short drive, and the vehicle would normally lock the doors at 5 mph. Well I think when ...	15
	1996 Geo Prizm LSi 1.6L timing belt VIN: 1Y1SK5268T This was a real pain, The correct timing procedure for when cams are removed to replace a head gasket are as follows. First you need to line up the 2 dots on the cams so they are level with the top of the head/valve cover rail. The dots should almost be touchi...	10
	1999 GMC Sierra 1500 SL 5.3L fuel gauge, oil pressure gauge, brake light, secur VIN: 1GTEK19TM0 sorry for the delay and thanks to everyone who replied turn out that the body control module was bad. installed body control module and had reprogrammed . problem solved	9
	2004 GMC Yukon Denali 6.0L oil pressure VIN: 1GKEK63U74 the customer authorized us to install aused engine in this vehicle. we are keeping the core and plan to tear it apart for inspection & repair. thank you for the replies that i received. i believe that redline racing gave the most correct diagnosis for our prob...	6
	2001 Pontiac Firebird 3.8L Temperature gauge VIN: 2G2FS32KX1 Thanks for the replies. I suspect I have learned a valuable lesson here on GM's idiotic tendencies. In my opinion if the t'stat opens too quickly and temp doesn't get to normal, that is not a good reason to have the temp guage become unusable. But that's ju...	4

(Also Available: All, Asian, Chrysler, European, Ford, GM.)