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Prev Professional Automotive Repair Technical Discussions for May 18, 2010
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Open Help Requests for GM
Help Request Answers
1996 Buick Skylark Limited 3.1L No Start, Stall, MIL Lamp on VIN: 1G4NJ52M6T
ok here it is i'm stuck every dash light is on it will start for a second and die and no rpm some times i can get it started and stay runing but it all stays the same all lights on and no rpm and i cant comunecate with the computer i just cant figer it out i w...
2001 Buick LeSabre Limited 3.8L MIL Lamp on VIN: 1G4HP54K41
I`v been working on this car for a few weeks now. it keeps throwing a p0300 code, i hooked up my modis and found that the missfire count high on cyl 3 and 6. i changed the coil pack and rechanged the wires with same code. iv tried to do the ckp relearn but it ... Trouble codes: P0300 (Random Missfire)
2004 Buick Regal LS 3.8L No Start VIN: 2G4WB52K94
This Buick was towed to our shop with a no cranking condition. I thought it was the starter, however, found no voltage signal from the ignition switch to the starter, using a power probe if I supplied power to the starter solenoid it cranks over fine. We did a...
2004 Cadillac CTS 3.6L Engine VIN: 1G6DM57714
Engine has always used a little oil but recently started excessive consumption. Used 4 qts of oil on a 1500 mi road trip. Have to add oil often while driving in town. Car has had Amsoil full synthetic oil in since about 80K mi and I assume Mobile 1 prior to th...
1986 Chevrolet K30 Scottsdale 7.4L Cooling Systems VIN: GCHC33W9G5
Hi, every one they had rebuilt engine in this truck,when they brought the truck to us. Passed block test . New thermo. New water pump,new radiator, and changed the fan clutch 3 times , this is the problem;!!! driving around the city is fine , go on high way i...
1991 Chevrolet Camaro Z28 5.7L Excessive Emissions, Poor Idle Quality VIN: 1G1FP33F2M
vehicle comes back with a rich condition.found tps to be working backwards,idle readings are 4.75 volts/wide open volts are 0.5 volts.i went to dealer and got oem sensor,still same results.when i start car with no sensor attached,the reading is 0 volts on scan...
1993 Chevrolet Camaro Z28 5.7L Hesitation, excessive pressure VIN: 2G1FP22P9P
Brought to me from another shop. After 30 minutes of idiling, fuel tank builds up excessive air pressure. Fuel pump becomes loud. Fuel system does not hold pressure with key off.
1995 Chevrolet Camaro 3.4L Cooling Fan VIN: 2G1FP22S8R
Just got car from cust came in overheating checked out found bad headgasket. Replaced gaskets t-stat ran car after repair found why overheated and cook gasket. Fan not coming on fan motor ok,runs with temp sensor un plugged tested temp sensor checked out ok.Ha...
1998 Chevrolet K2500 Silverado 5.7L Hesitation, Stall VIN: 1GCGK24R7W
vehicle towed to shop with complaint of stalled while driving @ 60mph. customer stated vehicle would not restart. upon arrival at shop vehicle started and would idle fine. the problem is that it will not accelerate unless you feather the foot pedal.if you can ...
1999 Chevrolet Silverado 1500 LT 5.3L No Start, MIL Lamp on VIN: 2GCEK19TOX
Vehicle came in with Check Engine Light on with a P0336 code running rough at times. I put in a new crank sensor then the vehicle would not start, put the old one back in and vehicle started, code P0336 did not reset. I put in a second NAPA sensor and vehicl... Trouble codes: 00336
2002 Chevrolet Trailblazer LS 4.2L Electric Window VIN: 1GNDS13542
Comes in with windows inop we tested the Drivers switch had ground and power so we condemned the switch. Installed new switch and tried to reprogram with the Standard Blue Streak Flash module. We could not get the module flashed with our Flash unit. The Dealer...
2002 Chevrolet Cavalier 2.2L Surge, Stall VIN: 1G1JF52FX2
Hello, I have an annoying problem with this ecotec engine. It goes very rich when the problem occurs which is on decel and at idle when you put it in gear. The engine surges then almost and sometimes stalls. My test results in the chart are when the problem o...
2005 Chevrolet Impala 3.8L pops back VIN: 2G1WF52K35
This is my second post. I didn't know how to add updated info after 1 time. This car will start cold and idle normally. If you accelerate (doesn't matter if light or heavy) the engine will start bucking and popping after about 2200 rpm's. It is not the rev lim... Trouble codes: P0350 (Ignition Coil Control Circuit), P1350 (Ignition ByPass Circuit)
2006 Chevrolet Silverado 2500 HD LS 6.0L No Start VIN: 1GCHC29U26
Hey all, having problems with this truck. Died while driving on hwy. After inspection, found good fuel pressure, proper injector operation, has no ignition spark. I have power to ignitin coils, but no signal from pcm to make the coils fire. I replaced pcm with...
2006 Chevrolet Trailblazer SS 6.0L No Start VIN: 1GNET13H16
thanks, truck came in as no start, bunch of codes stored lose of power to injectors ad coil. cleared codes and waited after awhile truck would restart on its own the later stall out. on test drive came back turn off went outside to bring in and you guessed it ... Trouble codes: P0689, P1516
2003 GMC Sierra 1500 4.8L No Start, No crank` VIN: 1GTEK19V43
PLEASE HELP! Car came in with Service 4WD light on. I found TSB for faulty TCCM and flash update. I replaced TCCM and performed reprogramming through GM-TIS. After this I thought I would be nice and check PCM for updates. I found an update for Idle surge so I ... Trouble codes: U1000 (Class 2 communication error)
2005 GMC Sierra 1500 5.3L Actuator VIN: 2GTEK13TZ5
Passenger side actuator for temp control is located on top of hvac module/housing and book shows removal of ip carrier. Is there an easier way or does rhe 5 hours the book calls for enough time. Thanks in advance for your help.
2003 Hummer H2 6.0L power windows,locks,cluster VIN: 5GRGN23U83
Hello everyone,thank you for reading this.I have this Hummer that drove in with complaint of rear power windows and rear door locks inoperative.I checked all fuses and grounds to these circuits.Motors are not the cause because i can make them work by alternati...
1996 Oldsmobile Achieva SC 2.4L Surge VIN: 1G3NL12T7T
The car was brought to me with the problem of a surge that would happen at idle. First thing that checked was all the usual including compression, vaccum(steady 20 inches at idle), fuel pressure, engine sensor grounds on bell housing and for carbon build up on...
2003 Other GM H2 6.0L No Start VIN: 5GRGN23U73
This vehicle was broken down at a customers home with a no start found the pcm b fuse was blown replaced it and it started up but ran at ruduced power checked the codes and found the 1518 wich i beleived to be because the pcm was not alive to communicate clear... Trouble codes: 1518 (Tac communication/memory)
1999 Pontiac Grand Prix GTP 3.8L Poor Idle Quality, Cuts out VIN: 1G2WR5213X
I really need help with this one. This is one of my loaner cars. 99 Grand Prix 3.8 Supercharged. The problem is that shortly after starting the car, its like all throttle control is lost. If you accelerate very slowly, it will get up to 35-40 mph but if you ac...
2000 Pontiac Montana 3.4L Cooling Fan VIN: 1GMDX03E3Y
This van came in today for what I assumed would be a simple diagnoses/fix. The cooling fans are inoperative. Fans power up when commanded by scan tool. All related circuits are good including ECM grounds. Coolant temp sensor is accurate as viewed through data ...
2003 Pontiac Grand Prix GT 3.8L MIL Lamp on VIN: 1G2WP52K73
Hi all, and thanks in advance. I have this Grans Prix that came to me on 5-09 at 97k miles with a converter plugged. We replaced converter with aftermarket. I have used these converters and have not had any problem with them. Car returned in 11-09 @102k miles ... Trouble codes: P1133 (testing and results)

Fixes & Summaries for GM
Fix/Summary Answers
1999 Cadillac Eldorado ESC 4.6L No Start VIN: 1G6EL12Y2X
This is where it gets interesting the previous shop put in a new computer called the flash guy and he couldnt communicate with the PCM .I bought a computer from my parts store and had them flash it. This is where I could comunicate and I got the password missm... Trouble codes: P1631 (Password missmatch reprogram ecm), P0630 (b2750).
2000 Cadillac Seville STS 4.6L Blower, Fan Speed control VIN: 1GK6KY5493
We have pulled the motor and it had some junk in it around the armature, and after thinking hard...LOL, I put a new module and motor together in it. There was no sign of water damage. I tested it for 2 days and so far so good. We are going to ship it. I still ...
2003 Chevrolet Corvette 50th Anniversary Edition 5.7L MIL Lamp on VIN: 1G1YY22G53
First, thanks to everyone who replied. Most suggested doing a crank variation relearn on the vehicle. I had already done that and forgot to mention it in my original post (sorry). I let the customer take the car, and was going to get it back in when I sorted t... Trouble codes: P0300 (random misfire).
2004 Chevrolet Tahoe LS 5.3L No Start VIN: 1GNEC13Z04
Thanks Guys for all your help! This one had broken ground wire on back of head passengers side! This morning I had the TAC module unplugged and it started right up with NO acceleration or power! I got it over to rack so we could check the grounds. I had seen ... Trouble codes: U0107 (Loss of tac serial data), U1000 (Class serial data malfuntion), U1016 (Loss of class 2 serial data vcm/pcm).
2007 Chevrolet Silverado 1500 HD Classic LT 6.0L MIL Lamp on VIN: 2GCFK13Y87
So everyone that replied was correct in the the actuator is the bolt for the cam gear so thanks for the help there! The actual fix for the vehicle was actually just a can of motor flush and an oil change with good quality oil instead of the inexpensive stuff ... Trouble codes: C0561 (c0900-), C0900, P0011, P2119.
2000 GMC Jimmy SLT 4.3L MIL Lamp on VIN: 1GKDT13W9Y
This thing is out the door and MIL off with no codes and somewhat fixed, It may be back and give me another opportunity. I had checked all signals to the tank pressure sensor however I checked the ground by installing a test light to the battery and and sensor...
1997 Pontiac Sunfire SE 2.2L passlock/cluster VIN: 1G2JB1248V
Alright, the moment everyone has been waiting for. The UART connection at the OBD2 connector is not the same wire as that feeds the cluster. Underneath the radiator there was a break in the UART (tan) wire, and a few others. I cleaned them up, soldered and ...
2000 Pontiac Grand Am GT 3.4L Headlamps VIN: 1G2NW52E0Y
Thanks to all of you awesome techs who wrote to help with this one! The problem turned out to be the junction (relay/fuse) box after all. There should have been continuity between the l/h headlamp fuse, pin 87a and pin 30 of the DRL relay in the normally-clo...
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