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International Automotive Technicians Network
Prev Professional Automotive Repair Technical Discussions for February 22, 2010
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Open Help Requests for GM
Help Request Answers
1994 Buick Regal Gran Sport 3.8L Misfire VIN: 2G4WF55L4R
Hi gang!!! i got stumped on this one, car came missing on cylinders number 3 and 6 (Top coil), they have no spark at all, interchange coils with no change, replaced ignition module (new one), no change, replaced ckp, no change, replaced computer and the proble...
1993 Chevrolet S10 Blazer 4.3L No Start, Surge VIN: 1GNDT13W0P
this vehicle came in for poor performance .plygs were worn hard 75-80 thou. tuned with new plugs ,cap &rotor . still had poor performance ,tested fuel press was very ericatic. replaced pump .still has poor perf. under accel surges severely .intermittenly wont ...
2000 Chevrolet Express 3500 5.7L High idle VIN: 1GCHG35R7Y
Ok so I am a little stuck. I have a 2000 G3500 Chevy Van that came into my shop. The customer complained of a high idle. The idle seems to sit at about 1100 rpms in Park, and about 800 in Drive. It looks like someone has installed a new IAC valve. The weird pa...
2001 Chevrolet Malibu 3.1L passlock sys VIN: 1G1ND52JX1
This car has come in on the hook several times for a no start,and again today. It started as soon as I turned the key as always. The only direction I have to go in is this b2960 code pulled from the BCM. I went through the chart on alldata and all readings loo...
2002 Chevrolet Tracker LT 2.5L MIL Lamp on VIN: 2CNBE63492
good morning all. i have this cheverolet geo tracker that intermittantly will illuminate the mil with dtc p0300. i have replaced the spark plugs so far. every time it comes in it runs just fine. i can never get it to act up. freeze frame shows that it happens ... Trouble codes: P0300
2002 Chevrolet Trailblazer LT 4.2L reflash problem VIN: 1GNDT13S52
hi reflash techs. I have a 2002 trailblazer that came in for a 4X4 problem. I replaced encoder and moter on T-case. They said I had to reflash t-case module. It had the latest update but since I was their I thought I would update any other systems. When I wen...
2003 Chevrolet Silverado 2500 HD 6.6L Misfire VIN: 1GCHK23163
Nasa called and they want their shuttle back! I got this Duramax that has what I think is an injector or sleave problem but I cant prove it out because the scanner keeps dropping communication when I try to run a balance test or even just reading codes or fail... Trouble codes: P1223 (injector 1 driver circuit voltage), U1800 (pcm lost communiction with ficm)
2007 Chevrolet Avalanche LT 5.3L airbag light VIN: 3GNEC12J07
hi techs. this truck has the air bag light flashing all the time. checked for codes found a p1860, drivers lumbar position sensor circuit. daignosed wiring etc,function test, no problems founnd. cleared codes and it didnt return ,but airbag light is still flas...
1997 GMC Savana 3500 5.7L Misfire, MIL Lamp on VIN: 1GDHG31R5V
Thank you for your help ahead of time. This customer is a regular and has us do some work and he does some of the work. He keeps getting a code for the cam sensor being bad and we have replaced and he has replaced it, plus he put in a new distributor still aft...
2006 GMC Savana 2500 4.8L MIL Lamp on VIN: 1GTHG39V86
Van came in with complaint of rough idle when cold and mil light on. When I got the vehicle it was hot so I did not duplicate the cold start complaint. Scanned van found P0171 and P0174, long term fuel trim stuck at positive 24% and short term moving around in... Trouble codes: P0171 (Lean exhaust bank 1), P0174 (Lean exhaust bank 2)
1997 Oldsmobile Aurora 4.0L Misfire, Poor Fuel Economy VIN: 1G3GR62C9V
i have a 97 olds that has missfire at cly.2&3 have ck.comp. replaced wires at 2&3 ALSO plugs.ck.inj.on lab scope also ck.fuel pressure reg.not leaking.st1 0 st2 16 lt1 16 lt2 38 i know these ar very hi but can not find what is causing them to be this high.foun... Trouble codes: 300 (missfire)
1989 Pontiac Firebird 2.8L Lighting VIN: 1G2FS21S4K
vehicle came in with directionals not working. upon check out, found blown fuse. replaced fuse, took tail light lens out of car and drove approx 10 miles using directionals. brought vehicle back to shop, reinstalled all parts and was ready to call the customer...
1992 Pontiac Bonneville SSE 3.8L Control Panel VIN: 1G2HZ52L6N
Started the car one day, and the HVAC control assy was blank except for three line segments. No heat, AC, or blower. Followed the ALLDATA trouble shooting diagrams, which lead me to the E&C Data Line Test. The E&C component identification on my Tech 2 does not...
2007 Pontiac G6 2.4L Cuts out, Misfire, MIL Lamp on, spark knocking VIN: 1G2ZG58B17
customer came in because check engine light was on, scanned the pcm and found a misfire code and converter code. also complained that at highway speeds RPMs jump to 4 grand. only could get the car to act up doing 70 plus on highway. syptoms are hard accelerati... Trouble codes: P0301, P0420
1997 Saturn SL2 1.9L MIL Lamp on VIN: 1G8ZK5277V
Hi everyone thanks in advance for taking the time to look into this one. Constant p0711 replaced trans and eng temp sensors and connectors. VEH had several codes before repairs runs great now (was stalling and rich). I clear code returns 2 seconds after I star... Trouble codes: P0711

Fixes & Summaries for GM
Fix/Summary Answers
2002 Buick Rendezvous CX 3.4L blower motor VIN: 3G5DA03E32
Thanks to all that replied. We finally found a intermitted short on the tan wire circuit 63 between the fan switch and blower resister. when fan setting was on low it would take out the resister.
2003 Cadillac DeVille 4.6L Surge, Misfire, MIL Lamp on VIN: 1G6KD54YX3
Thanks for all the expert help, guys. After I literally spent hours checking all the sensor wiring, and hooking up an Oscilloscope to the signal wires at the PCM, I discovered that when I originally plugged in the connector on the new replacement Upper Cranks... Trouble codes: P0385 (Upper CKP Sensor B Circuit).
2003 Cadillac DeVille 4.6L radio VIN: 1G6K054Y53
Howdy there, well I guess in a round about way I took most of Y'alls advice and "REBOOTED" this pos. I disconnected the amp and the head unit and then for good measure disconnected the battery cables and connected them together overnight, after reassembly the ...
2004 Cadillac Escalade ESV 6.0L gauges and charging VIN: 3GYFK66N7G
Thank you to all who replied. This vehicle deceived us in that the regulator in the alternator is controlled by 2 wires from the pcm. Apparently something in the regulator would intermittently quit working and as soon as the alternator would quit charging the...
1993 Chevrolet C3500 Cheyenne 5.7L No Start, Cuts out VIN: 3GCJC44K9P
thanks a milion ! i replaced all body and engine gounds, replaced icm its been 2 weeks still running thanks againg?
1998 Chevrolet Tahoe 5.7L Compressor VIN: 1GNEC13R5W
I too a while to confirm this repair because of the off and on again nature of the issue. I found the 2 wires headed to the high pressure switch pinched in a bracket. Several replies state this is a issue where someone else went in and moved things around. Aft...
1999 Chevrolet Malibu 3.1L Poor Idle Quality
2001 Chevrolet Express 3500 5.7L Poor Idle Quality, Misfire, MIL Lamp on VIN: 1GBHG31R61
I was unable to do a crankshaft relearn because of the hard faults. Replaced alternator. Install shim for crankshaft position sensor. Part number: [...]. Did crankshaft relearn. Engine runs good. Thanks for the replies. Trouble codes: P0335 (CKP Sensor A Circuit Problem), P1637 (Generator L-Terminal Circuit), P1638 (Generator F-Terminal Circuit).
2002 Chevrolet S10 4.3L brake light VIN: 1GCCS19W92
tony from north carolina hit the nail right on the head. swapped horn relay for the chmsl relay and took care of the problem. thanks guys
2004 Chevrolet SSR 5.3L roof VIN: 1GCES14P44
Thanks for all the help. I did get a nice email with ever bit of diagnostic info that gm has for this problem (thanks christopher) Unfortunately I had the same info.It was a very nice gesture. The customer picked vehicle up before repair could be done, but a I...
2005 Chevrolet Impala 3.4L Speedometer VIN: 2B1WF55E45
Cleaned and tighten connection at speedometer and problem went away
2006 GMC Sierra 2500 HD SLE 6.0L MIL Lamp on VIN: 1GTHK29U76
Hi everyone, well this truck showed no problems with any system at all except the check engine light flashing, and the truck ran great while this awas all happening. The customer took the truck to the dealer, and they did $1100.00 worth of stuff to the truck ... Trouble codes: P0300 (Random misfire).
2001 Pontiac Montana 3.4L Heater VIN: 1G2WP52K51
Hey you guys nailed it, the cabin air filter was plugged. It kind of looked like there was a mouse living in there at one time. I understand why that fixed my weak airflow problem, but I don't understand why it fixed the cold air at idle problem. But it is fix...
2007 Pontiac Grand Prix 3.8L blower moter VIN: 2G2WP52285
I would like to thank everyone for the help, it was the ignition switch that was the problem. the car has been gone for a while now and we have not heard from the customer
2005 Saturn Ion-1 2.2L Engine VIN: 1G8AG52F65
did the 30 minute relearn everything is good now thanks for all the good advice iatn is a life saver
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