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International Automotive Technicians Network
Prev Professional Automotive Repair Technical Discussions for November 10, 2008
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Open Help Requests for GM
Help Request Answers
1968 Chevrolet corvette 427CID Wipers VIN: 194678S403
My biggest problem with this car is that I am having a problem locating a wiring diagram, vaccum diagram and proper testing procdures needed to diagnosis and repair the problem. I have a 68 mitchell manual but the diagram in there doesn't even come close to wh...
1981 Chevrolet Corvette 5.7L vacuum booster VIN: 1G1AY8769B
Help, I seem to have jumped into a pile this time. Can any of you old corvette guys tell me how to get the power booster out of the car? I know this seems simple but it is not. we removed the instrument panel, steering colum and related accessories to gain ace...
1998 Chevrolet C3500 Cheyenne 7.4L p/s steering pump VIN: 1GBKC34J9W
When driving vehicle, steering wheel will get hard to turn, then vehicle will loose it's brakes. We've replaced two different pumps and two different hydro-boost units and a gear box. All have been genuine GM parts. Also replaced pressure and return power stee...
2001 Chevrolet Suburban 1500 5.3L MIL Lamp on VIN: 3GNEC16T21
Replaced downstream O2 sensor on passenger side (Bank 2, Sensor 2), cleared the code. MIL & same code came back 35 miles later. My scanner is showing very LOW voltage output from the new sensor. How can I test the output voltage of the new sensor? Trouble codes: P0157 (02 Sensor Circuit Low Voltage Bank 2 Sensor 2)
2002 Chevrolet Malibu LS 3.1L No Start VIN: 1G1NE52J72
No start after having been momentarily parked. See tests above. Spark is good as well as good cranking speed. Scanned for errors = known found. Watched datastream: 24x & 3x CPS signals are good and viable while cranking. While cranking, the car will run briefl...
2003 Chevrolet Suburban 1500 LS 5.3L steering wheel VIN: 3GNFK16ZX3
Customer complains when hits a bump on freeway 65 mph steering/whole vehicle starts to shudder until he slows below 50 mph. This sounds like a steering damper problem , which I have seen many times before. However this vehicle does not have a steering damper/...
2004 Chevrolet Express 3500 6.0L Poor Idle Quality, Cuts out, Stall, Misfire, MIL Lamp on VIN: 1GCHG39U14
this van has been a bit of a problem child for quite some time now...what it does is mostly cold open loop u start the van it runs good no problems what so ever u put it in gear it starts to gallop and missfire it may even stall. if you drive with both feet it... Trouble codes: P0300
2006 Chevrolet Corvette Z06 7.0L Surge VIN: 1G1YY26E46
This vehicle has a severe surge / hesitation. It is bad when it is cold and is only slightly noticable when warmed up. There are no engine codes, fuel pressure is good. There is also a rattle / clunk from the drivertrain. Do these have the dual mass flywheel s...
1995 GMC jimmy 4.3L No Start VIN: 1GST145698
i have thsi 1995 gmc jimmy 4x4 it blows the ecm/ignition fuse 20 amp, fuse#10 it only blows in 4x4 mode , he has trid all things but fuse only blows when he was removing small trees from his new property i had a few suggestions for him we chose to use iatn , i...

Fixes & Summaries for GM
Fix/Summary Answers
1991 Buick Park Avenue 3.8L No Start VIN: 1G4CW53L8M
Thanks for the reply's. Some are way off. This car can have spark without ECM or Cam sensor. Not sure why, but GM pinpoint test had us replace module. Best to scope sensors. Ended up being a bad crank sensor. Hard to deal with when new parts are bad.
1996 Buick Roadmaster Collector's Edition 5.7L Misfire VIN: 1G4BN52P0T
after further diagnosis with scope, we found 2 bad injectors on cylinders 2 and 4. They are putting extra fuel through those cylinders and the backfiring we are hearing is actually fuel burning off in cat. Trouble codes: P0300 (engine misfire detected), P0155 (02 heater circuit bank 2 sensor 1), P1441 (Evap system flow during non purge).
2004 Cadillac CTS 3.2L Starting VIN: IG6DM57N04
thank you for your help.I did check all grounds & ignition switch & powers I flet problem was in p.c.m. so i replaced Know vihicle will not even crank over. Not sure at this time if I am going to go further. closing out if I have any more info I will up date. ...
2005 Cadillac CTS 3.6L airbag VIN: 1G6DP56715
what you guys have said is what I thought no I don't have a tech 2 so I unfortunatly told customer what I thought (seat sensor) and that they would have to goto dealer. thanks to all for your help
1986 Chevrolet Corvette 5.7L Poor Idle Quality, Hesitation, Cuts out VIN: 1G1YY0782G
Thank you every one that helped. I replaced the valve seals they were hard and brittle,installed new injectors and replaced intake gaskets. The car is running good. I also installed hotter plugs just in case of a ring problem witch the customer did not want to...
1990 Chevrolet LLV 2.5L No Start VIN: 1GBCS10E9M
thanks for all the replies, vehicle finally quit in my shop, traced problem to fuel pump relay, replace relay and all is well, thank you again
2001 Chevrolet Venture LS 3.4L Engine VIN: 1GNDX03E31
Thanks for the help! As I suspected, a head gasket needs to be replaced. But, I didn't think that a head gasket could cause this problem, especially without any coolant loss. I hoped someone else would have a different idea, but almost everyone suggested a hea...
2002 Chevrolet MedDutyTruck 5.7L MIL Lamp on VIN: 4KLB4B1R02
Most replies refered to setting cam retard and doing a crank relearn. We had done that, but I didn't write it in my original post. After checking everything that could cause a true misfire (including a test dist. and injectors) we ordered a reman PCM. We in... Trouble codes: P0300.
2004 Chevrolet Monte Carlo LS 3.4L gauges VIN: 2G1WW12E34
I want to thank everybody for their very quick responses to my problem. Everybody was right about what was wrong. It was the Instrument Module. I found out that you can have a GM dealer send it in and have it checked. If there is no problem found, just pay shi...
2005 Chevrolet Silverado 1500 LS 5.3L power steering VIN: 2GCEK13T95
We will call the steering gear the fix, when we had no assistance with an increase in RPM, but you could hear the pump strain as if the gear was at a full left or right, only had a 1/2 turn left or right then assistance stopped, it had a 670 box, the fix is to...
2005 Chevrolet Cobalt LS 2.2L MIL Lamp on VIN: 1G1AL52FX5
thank you for all the replies. modis would not do it. i took it to a friend with a tech II and he reset it. modis didn't work this time. thank you again. Trouble codes: P0315.
2006 Chevrolet Trailblazer LT 4.2L MIL Lamp on VIN: 1GNET16S36
Yes this one is fixed. It was bad injectors! throtle body and maf sensor were clean as stated before. When i removed the intake to get to the injectors a lot of oil came out of intake. the injectors had a carbon layel bilt up on the ends like the engine has b... Trouble codes: P0171.
2008 Chevrolet Silverado 2500 HD WT 6.6L No Start VIN: 1GCHK23608
Everyone was right there is a service buelitin (2202189 numb.08142a)that addreses this issue exactly. We reflashed the engine control module with techII and gm's TIS to WEB, and the vehicle started and runs fine. This vehicle was under warrany but the custome... Trouble codes: P062F.
1984 GMC C7000 .0L no power VIN: 1GDL7D1B0F
Replies that talked about linkage being tripped were right on, although no one said why linkage trips and needs to be reset? Working good so far, has full power again. Thanks to all who replied. IATN is irreplaceable.
2003 GMC C6500 Topkick C6C042 8.1L loss of power VIN: 1GDJ6J1E83
Being the vehicle's symtom was intemittent and never observed in the shop, we disconnected,inspected and cleand all power and ground supplies and connections. reassembled and returned for service. It has been several weeks with no complaints at all. Thanks to ... Trouble codes: P0220 (TP or APP Sensor Circuit 2 Failure).
2005 GMC Envoy SLE 4.2L MIL Lamp on VIN: 1GKDT13S95
Sorry it took so long to reply but the cutomer was doing the repairs himself. When I found nothing wrong I told the customer to replace the new sensor they put in from autozone with a factory ac delco sensor. They told me they did that and the light came back ... Trouble codes: P0054 (rear oxygen sensor heater resistance).
1991 Oldsmobile 98 Regency Elite 3.8L Poor Idle Quality, MIL Lamp on VIN: 1G3CW53L8M
Thanks to everyone. Lots of replies. Consensus is the proper fix is to remove the cover to access the cam gear. The magnet (called an interruptor) installs from the back of the cam gear. Even though this car only has 36000 original miles, I'm going to replace ... Trouble codes: 41 (Cam Sensor).
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