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International Automotive Technicians Network
Prev Professional Automotive Repair Technical Discussions for April 30, 2007
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Open Help Requests for GM
Help Request Answers
1995 Buick Century Special 2.2L Hesitation, Surge, Misfire VIN: 1213456789
thank you for your time with this car its a 95 buick with a 2.2 i loose cyl 1&4 on a load no spark it has 2 new coils and new plugs ,wirers and module and pcm and prom from gm i let it idle and they come back
1996 Buick LeSabre Custom 3.8L Starting VIN: 1G4HR52KVH
If the electric doesnt go out again, third try. Hello everyone, this LeSabre has the security light flashing. The owner went into the store and came out and the car would not turn over. I read the archives and learned some things about this system. This is onl...
1993 Chevrolet S10 Blazer Tahoe 4.3L Poor Idle Quality, Very High Idle VIN: 1GNCT18W8P
Guys this Blazer is driving me nuts. Came in with an extremely high idle. Customer says it started suddenly and is always high. I have replaced the Idle Air Control with a new one, replaced map with known good one, checked the coolant temp for proper reading, ...
1994 Chevrolet G20 Chevy Van 4.3L Poor Idle Quality VIN: 1GBEG25Z3R
This one came in for a rough running after it sat for a few hours, we put a fuel pressure gauge on it and verified a rapid fuel pressure drop but never did see the rough running while the fuel pressure gauge was on it. We did get it to rough idle the very firs...
1998 Chevrolet Malibu 3.1L No Start VIN: 1G1ND52M4W
It had a lot of codes so I wrote them down and cleared them. I check crank and cam sensors at the computer and found sensor reference voltage grounded I unplug the cam sensor first, no change. Then I unplugged the 24x sensor and volt went up. I look at sensor ... Trouble codes: P0102 (Mass Volts Low), P0336 (crank sensor), P1107 (map volts low), P1115 (Coolant sensor high), P1122 (tps volt low)
2002 Chevrolet Astro LS 4.3L Misfire, MIL Lamp on VIN: 1GNDM19X82
I just installed a 4.3 vortec engine in the Astro and started it up and it ran good for a few hours. After awhile the SES light came on and it started indling really rough. Well I pulled in the computer and it stated multiple cylinder misfire. I noticed that t... Trouble codes: P0301 (Multiple Cylinder Misfire)
2005 Chevrolet Classic 2.2L air conditioning VIN: 1G1ND52F45
cant get this a/c system to take a gas charge. had tryed some liquid charge. either way have to manually hot wire the compressor to do either. prior front damage. holds pressure, but appears blocked somewhere. nothing gets cold and almost no gas is getting int...
1994 GMC Olympia 5.0L co VIN: 1RC9408367
Getting complaints from our ice arena about heavy exhaust smell inside the ice arena. First thing I did was grab my CO monitor and I started at the Zamboni room and got a "0" reading. When I stepped inside the arena I got a reading of "20"PPM. Walking to the f...
2001 GMC Sonoma SL 2.2L Poor Idle Quality, Surge, MIL Lamp on VIN: 1GTCS14591
vehicles has new map sensor because the voltage was going to 4.5 volts at idle when it should be between 1-2 volts at idle. after driving it under load it suddenly bogs out. thats when the crazy map reading comes in. i have keyed the car off after the poor dri... Trouble codes: P0122
2004 GMC C5500 Topkick C5C042 6.6L No Start, Hesitation, Misfire, MIL Lamp on VIN: 1GDE5C1254
Hi everyone This vehicel came to shop this morning. This vehicle crank no start, no metter cold ot hot but It will start everytime we spray cab cleaner, idle feel OK. but when we road test, this vehicle was knocking alot, missing, and white smoke. I followed t... Trouble codes: P0522 (Oil pressure sensor circiut signal low), P0304 (cylinder 4 misfire detected), P2228 (Baro sensor circuit signal low)
2005 Hummer H2 6.0L Service Indicat VIN: 5GRGN23U64
Hi everybody, i need your help on this hummer, everytime i start it it will show me change engine oil on the cluster, anyway to reset it manualy without scanner. Best Regards
1995 Oldsmobile 88 Royale 3.8L oiling system VIN: 1G3HN52K3S
the radiator on the car has engine oil in it. radiator does not have engine oil cooler.i adapted shop air to the oil pressure sending unit regulated down to 10 psi and had oil coming out of radiator.removed oil pan and front cover but cant visually see any cra...
1989 Pontiac Grand Am SE 2.0L Stall VIN: 1G2NW54MXK
I need some info about the lock up torque converter. This car has the classic symptoms of a lock up converter not disengaging causing the car to shake real bad and stall when coming to a stop. I was under the impression when this happens it would stay engaged ...
1993 Pontiac Bonneville SE 3.8L electric door locks VIN: 15P1238226
Hi, looking for tips on door locks inoperative. I performed a tune up and customer is now complaining of door locks not working with switches, or with key fobs. I did no interior work on vehicle, problem just happened for no apparent reason. Probably a seperat...

Fixes & Summaries for GM
Fix/Summary Answers
1979 Cadillac Eldorado 5.7L ignition VIN: 6L57B9E614
we finally figured this one out. thank you to everyone who replied.the fix ended up being the ess decoder box grounded internally on cranking only. when the key was released would fire and run.were able to bypass with jumper wire at dist to verify jumpered gre...
1997 Cadillac DeVille 4.6L Misfire, MIL Lamp on VIN: 1G6KD52YXV
Well anyway, tried all avenues to find a cure for this caddy. Replies that were sent: coolant leak into #6, fuel regulator leaking inside runner, defective ignition module causing 1 cylinder to misfire, do crank relearn, check EGR for stuck open, check opposit... Trouble codes: P0300 (engine misfire detected).
1996 Chevrolet S10 2.2L comp VIN: 1GCCS1440T
Thanks for all the help. I found out that it has a Variable Displacement compressor, it does not cycle, it has a control valve in the comp. I reclaimed, it was 12 oz low on freon, recharged to spec, will see if that helps any. Most said it ain't quite broke ye...
1996 Chevrolet Tahoe LS 5.7L 2-3 shift VIN: 1GNEK13R7T
thanks to those that replied, found the pcm was bad. replaced it and got rid of code. trans 3-4 clutches wereburnt installed new trans. customer happy. again thanks
1999 Chevrolet C3500 5.7L Brakes VIN: 1GBJC34R8X
Well it's fixed. Thanks for the many responses. Many of you were right on the money. Although the front suspension showed no signs of excessive movement and there were no signs of external leakage, we replaced the steering gear box, flushed the system and repl...
1999 Chevrolet Silverado 1500 5.3L Poor Idle Quality, Surge VIN: 2GCEK19T3X
thank every one for their advice. vehical was picked up over weakin and possible return monday for further diag. yes i had fuel presser gauge hooked up entire time of work preceder. one time i noticed dropage of 5 psi over a period of setting. hopefule vehice ...
1999 Chevrolet Silverado 1500 5.3L Coolant Loss VIN: 2GCEK19TXX
It is possible the head is cracked in the front, right oil drain galley. The customer has chosen to take the truck home and finish the job there. As I was entering this vehicle on the help request the engine choices didn't include the 5.3 and wouldn't allow ...
2000 Chevrolet Silverado 1500 5.3L brake pedal VIN: 1GCEK19T21
lots of thanks. it was the calipers sucking air. this truck has a new brake system now isn't that lame!
2003 Chevrolet Express 2500 4.8L Starter VIN: 1GCGG25V43
Gm TSB 1535230 discusses dtc 706: the symptoms match exactly. Will still be looking for a wiring harness problem somewhere around the fuse box or routing near the PS hose. The other side of this is to reprogram the PCM so that when/or if this code arises again...
2005 Chevrolet Express 2500 5.3L Daytime Running Lights & Running Lights VIN: 1GCGG25V25
We finally got our hands on our new Tech 2 and pulled a BCM Code P2585 Marker Lamp Circuit. We could demand daytime running lights through the BCM and the marker lights would come on instead. We went to the interior fuse panel (which is under the drivers seat,...
2002 GMC Sierra 2500 HD SL 6.6L No Start VIN: 1GTHK29132
boy i was out to lunch on this one. the problem with this one was the fuel supply hose that runs from fuel filter to pipe behind alternator was soft and was sucked together, also replaced fuel filter customer said truck runs better than it has in 2 years.
2003 GMC Savana 3500 6.0L Poor Idle Quality, Stall VIN: 1GTHG39U73
i did go and replace the complete throttle assembly with one from the dealer and it looks like we have a good repair,no more stalling and a nice idle.
2003 Hummer H2 6.0L No D4 or D3 VIN: 5GRGN23U83
Everyone is replying with the same answer, 'pull the unit apart'. Because we are in California we are recommending that the customer replace the transmission with a re-manufactured (Jasper) unit. In Cali we have to give a time and cost estimate to tear down an...
1995 Oldsmobile Aurora 4.0L no communication VIN: 1G3GR62C6S
PCM did repair the original problem. The idle speed would not relearn due to a faulty cable on my scanner. I thought I had eliminated the scanner as the problem earlier because when the communication stopped with the original computer, I plugged in a different...
1999 Oldsmobile Aurora 4.0L Misfire VIN: 1G3GR62C3X
Well this vehicle was repaired with new spark plugs and wires. I had changed the missing cylinder plug and wire with no repair. Make sure you replace all of them together. Thanks for you help again. Chuck's Automotive
2002 Oldsmobile Bravada 4.2L battery draw VIN: 1GHDT13582
WOW! After grueling hours of wiring diagrams, teardown and reassembly, studying operation and some helpful feedback, we have tackled this *** (one!) It had a faulty rear BCM also sometimes called the keyless entry module (has more functions than keyless entry)...
2003 Pontiac Grand Prix GTP 3.8L brake pedal VIN: 1G2WR521X3
Well after pulling all my hair out I got another master cylinder and the peal got much better. I then put the old HCU back on and still had a good pedal(thanks NAPA). Thank all of you for the replies.
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