GM Automotive Technicians Technical Discussion and Fixes for Jan 24, 2007

Join Now

Prev	Professional Automotive Repair Technical Discussions for January 24, 2007 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
	1993 Buick Park Avenue 3.8L anti theft VIN: 1G4CW53L8P we replaced the steering column with a salvage yard unit and the vehicle will start and die immediatley. i know it is the anti theft system. is there a way to program the original module with the new column and key? we have not interogator machine here so, wil...	View
	1998 Buick Regal 25th Anniversary Edition 3.8L No Start VIN: 2G4WF5219W customers complaint is that vehicle will crank and will not start at times.had a p0336 crank sensor code,replaced sensor.still has same problem but no codes,and will not act up in the shop only when the customer has vehicle and it may go a few days at a time b... Trouble codes: P0336 (crank sensor)	View
	1988 Cadillac DeVille 4.5L Hesitation, Surge VIN: 1G6CD51595 This Vehicle Idles great but has an intermident hesitation upon accelerating from a stop.also while driving at freeway speeds it tends to hesitate & surge.Feul Presure is At 10 psi,No codes present.I did watch the throtle position sensor & map sensor while dri...	View
	1991 Cadillac DeVille 4.9L digtial Display VIN: 1G6CD53B3M The display for the fuel and ac controls do not display. Checked wires at the fuel data center per on demand and have all but the 16 volts from bcm. Ohmed wire from bcm to display and checked good. replaced with used bcm and still have no display. looks like t...	View
	1993 Chevrolet S10 Blazer Tahoe 4.3L No Start VIN: 1GNDT13W5P this vehicle when left over night will not start. (warm or cold outside temperature). replaced the cfi assembly, fuel pressure 55psi, spark strong, coolant temp reading accurate, no codes. after prolonged crank vehicle will eventually start. after that the veh...	View
	1993 Chevrolet Lumina 3.1L Misfire VIN: 2G1WW12M0T trouble code po300 - random misfire - cylinder #5 has dead miss. 100 psi compression, has good spark,(swaped coil, plug and wire with another cylinder to compare), replaced fuel injector, no vacuum leaks, pcv working, egr not stuck open, no forein matter by ma... Trouble codes: P0300	View
	1994 Chevrolet C3500 6.5L No Start, Cuts out, Stall VIN: 1GBHC39F2R Stalls at any rpm with hard restart. Occurs mostly with electrical load. Sometimes won't start and sometimes wont exceed 2000 rpms. Trouble codes: 13 (engine shutoff driver fault), 41 (brake switch fault), 99 (pedal position 2 ref fault)	View
	1996 Chevrolet C2500 Cheyenne 6.5L starter motor VIN: 1GCGC24F4T hello fellow iatn menbers. i have a 96 chevy truck. thats keeping cranking at times with key out of switch. we are on a second a/c delco starter. i have replace starter relay. relay is a/c delco test ok. when problem occurs purple wire from relay stays hot. pr...	View
	1997 Chevrolet C3500 6.5L Surge, Stall VIN: 1GCHC39FOV this vehicle was brought into my shop with a lack of power complaint.the customer has had the fuel filter replaced, 1 injector replaced, fuel pump has been replaced, and the injector driver module on the injection pump has been replaced.the vehicle has no dtc'...	View
	1998 Chevrolet K2500 Cheyenne 5.7L passlock VIN: 1GCGK29R9W here we go, another passlock ??. this truck came in with your standard start stall with security light flashing. first off there once was a remote start in this truck, so first we had to go and fix all wrecked wiring. truck relearned and worked good for a few ...	View
	1998 Chevrolet C3500 Cheyenne 7.4L Fuel gauge VIN: 1GBKC34J8W This truck had dual gas tanks at one time, now only the front tank remains.All the dual tank electrical connections and module are still present. If I connect two sending units to the original wiring, I can make the fuel gauge work.The problem is there is only...	View
	1998 Chevrolet S10 2.2L Hesitation, Misfire VIN: 1GCCS1449W This truck has a hesitation or misfire,most of time it happens in 5th gear cruising with light throttle.I can also make it happen if I lug it in 5th gear.It does not always act up.I thought it was a ignition misfire.I replaced the plugs and wires.It still miss...	View
	1998 Chevrolet Tahoe 5.7L No Start, Cuts out VIN: 1GNEK13ROW ok this is a long story here goes cartowed in no start tested to verify.car would start run 2 sec then stop have seen problems w security system read various posts and determined it was security related replaced steel outside casing that contains pass lock sen...	View
	2002 Chevrolet Silverado 1500 5.3L MIL Lamp on VIN: 2GCEC19T22 thanks in advance for everyones help. this code is intermittant, when following the flow chart provided by alldata, it asks you to perform gm service bay test to vehicle first. i found under special tests in our genysis, what appears to be the same test,(is th... Trouble codes: P0446 (evap vent control malfunction)	View
	2004 Chevrolet Silverado 1500 5.3L Steering column VIN: 1GCEK14T04 Hey Group! This truck is giving us a little problem. There is a growling noise from the steering when you turn left. It doesn't happen every time and it has to be in the right spot in order to make the sound but it is definitely there! We started with this gro...	View
	2004 Chevrolet Silverado 3500 6.6L Poor Fuel Economy VIN: 1GCJK33124 customer came complaining oil pressure droping to low buzzer would go off. when brought in check oil level was over full & thin . check fuel pressure at idle with scanner desired & actual whier very close increase fuel pressure to max desired went to 23,200 ac... Trouble codes: 234 (turbo over boost), 1093 (fuel rail pressure low during power enrichment)	View
	1996 Oldsmobile Aurora 4.0L No Start VIN: 1G3GR62C8T Help. Customer brought in this car and explained that when warm and you shut off car and go to restart after about 15 minutes it has long crank times. We can duplcate this in the shop. With the car at normal operating temperture, you shut down and leave it for...	View
	1994 Pontiac Grand Am GT 3.1L trans VIN: 1G2NW15M8R Ok this seems to be simple but.. The complaint is it doesn't shift.My findings are no power at pin e on trans connector.If i jump it the trans upshifts normal.Codes 28,59,75,76,77 there is no power to the egr valve either.alldata says the erls fuse is where th...	View
	2004 Pontiac Sunfire SE 2.2L speedo/tach VIN: 1G2JB12F04 customer states speed & tach read higher than normal while driving intermittently.some times tach does not work.runs & shifts o.k.no ses light on no pending codes or freze frame data to suport any pcm malfunction. no tsb's & no postings on fix data base found....	View

Fixes & Summaries for GM

	Fix/Summary	Answers
	1993 Buick LeSabre Custom 3.8L dash & park lights VIN: 1G4HR53LOP Had 3 replies with good grnrtal info. Confusing when there are 13 pages of light related wiring diagrams. One reply had the answer. Bad new out of box. Fixed 1 problem, and created a new 1. Rechecked all wiring at the switches and LCM. Found no current coming ...	3
	2000 Buick LeSabre Custom 3.8L abs VIN: 1G4HR54K14 Thanks to those who responded, you helped me make the correct repair to solve this customers problem. The relay inside the ABS Module was bad. The customer made the choice to have a used module from a local wrecking yard installed. It came from the same year, ...	6
	1991 Cadillac Fleetwood 4.9L Brake Pedal VIN: 1G6CB53B1M Well we finally got this one fixed. Thanks everybody for the help and inputs. All 3 of my techs were working on it and I took over the job personally. We did clamp off all 4 brake hoses and had a much better pedal but not as good as it should have been. When y...	17
	2004 Cadillac DeVille 4.6L No Start VIN: 1G6KD57Y44 We got blasted with 2 ice storms in one week and vehicle was sitting outside we cannot move it at this time so it has been moved to back burner. Thanks to the 4 replies Perry from CA suggested ground at alternator this check ok Paul from Penn said we needed te...	5
	1990 Chevrolet Corvette 5.7L Misfire VIN: 1G1YY238XL OK well this head scratcher is finally diagnosed, after testing several theories provided by IATN members I finally did a leakdown again on #6 cylinder and this time it was 30% and upon listening down the dipstick tube you could hear the air passing through th...	74
	1994 Chevrolet K2500 Cheyenne 6.5L No Start VIN: 1GCGK24F8R Thanks for all the help, I managed to find a little more history. The original owner said he had to replace the injection pump every 30,000 miles, so it is on its 3rd one now. They were all done at a GM dealership. The problem ended up being the PMD (FSD). I a... Trouble codes: 35.	3
	1996 Chevrolet Blazer 4.3L Poor Idle Quality, Misfire, MIL Lamp on VIN: 1GNDT13WOT yes i have fix this vehicle and thank to all that responded to my request. it was the pressure regulator as many of you suggested. thanks again Trouble codes: P0304 (misfire cylinder 5), P0306.	15
	1996 Chevrolet Express 1500 5.0L high idle VIN: 1GBFG15M9T Thanks to all who offered advice. After removing the throttle body for cleaning, a small hole was discovered in the throttle body near the throttle plate. Apparently the screw that held the throttle cable bracket to the throttle body was too long. The tip of t...	16
	1998 Chevrolet Monte Carlo Z34 3.8L Master Cylinder VIN: 2G1WX12K8W Ok, finally fixed it by going over the bleed proceedure several times. After the master was repalced the pistons in the ABS modulator needed to be at the top of their bores in order to bleed the rear brakes. After starting and running the engine the ABS and br...	8
	1999 Chevrolet Silverado 1500 4.8L No Start VIN: 1GCEK19VOX The problem ended up being the crank sensor. I could only get ign. voltage at computer when crank sensor was unpluged. I usually unplug crank sensor to test for voltage but in the case the starter was in the way so I left it plugged in when testing. The truck ...	17
	2002 Chevrolet Impala LS 3.8L Excessive Emissions, No Start, Poor Idle Quality, Stall VIN: 2G1WH55K32 Well, no backhoe required yet again, Thanks to all that took the time to reply, The repair was as simple as can be, numerus TSB's, just overlooked. I have never had a problem with fuel volatility concerns until now, This one is it... Turns out that the fuel th...	11
	2002 Chevrolet Trailblazer LS 4.2L No Start, Poor Idle Quality VIN: 1GNDT13S32 Vehical is fixed. It was the ground cable that bolts to the block... simple stupid	11
	1992 GMC Yukon 5.7L electronic hydraulic control unit VIN: 1GKEK18K1N First off,Thank you for your replies.I talked to the customer about his abs unit and told him about my replies from you guys.At this time he has opted out of replacing the expensive unit due to the age and mileage on this Yukon.I had suspected that it would ne...	5
	2001 GMC Sierra 2500 SL 6.0L battery VIN: 1GTHK23U41 hey guys thanks for all the replies. i checked with the dealer on this software update and he couldn't find any such update. maybe the guy who sent that would like to email me and elaborate. as for the overhead beacon issue which caused 80 mA draw, this is not...	7
	1995 Oldsmobile Cutlass Ciera 3.1L Blower Motor VIN: 1G3AJ55M0S Installed 20 amp circuit breaker and so far blower motor has been working fine. Customer will let us know if any other problems occur. Thanks for all of the replies and help.	7
	2000 Pontiac Grand Prix GTP 3.8L whole car VIN: 1G2WR5212Y thanks for all the replies most every one said it was in the axles inner joint and thats what it turned out to be. i replaced the left axle and everything is nice and smooth now who would of thought once again thank you john	15

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