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International Automotive Technicians Network
Prev Professional Automotive Repair Technical Discussions for October 20, 2005
International Automotive Technicians' Network (iATN) - Members Only
(Also Available: All, Asian, Chrysler, European, Ford, GM.)
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Open Help Requests for GM
Help Request Answers
1995 Buick Park Avenue 3.8L No Start, Cuts out, MIL Lamp on VIN: 1G4CW52K3S
This car came in with three historical codes. I am at home typing this so I donít have the numbers so I listed the codes. After sitting a while, then restarting and driving down the road sometimes this car will cut out on acceleration. Twice on deceleration th...
1995 Cadillac DeVille 4.6L tcc VIN: 1J6KF52Y3S
This car has a code po39. I have a6 volt drop on the groun of the TCC but I dont know where the ground is located out of the black box. What ground is used for TCC?
1977 Chevrolet Nova 5.7L No Start, Poor Idle Quality, Hesitation, Cuts out, Stall, Misfire VIN: 1X27L7L149
Hi guys. I feel stupid asking for help on an old-as-the-hills HEI system, but this thing has me baffled. It came in a couple of months ago with a no-start problem, no spark. We found a bad control module and replaced that along with the pickup coil for good me...
1994 Chevrolet Camaro Z28 5.7L No Start VIN: 2G1FP32P6R
Help needed from those w/ more GM experience. This car came in on hook, was not getting stable high res signal from dist.. Replaced dist--still no start. It does this really weird thing--after cranking it runs backwards for a couple revolutions with the key on...
1996 Chevrolet C1500 Suburban 5.7L Electronic VIN: 1GNFK16R2T
This truck has a P0753 1-2 shift solenoid code resetting intermittently. Trans suffered mechanical failure and was rebuilt last week. Code was setting before rebild along with P1870 and some others, P0753 is the only one coming back. When activating the soleno...
1996 Chevrolet Corsica 3.1L MIL Lamp on VIN: 1G1LD55M5T
after driving this car for awhile, you can come to a stop sign and the car will shudder, just like a 3T-40 will do when the TCC solenoid gets stuck on. But since this is a 4T-60, it won't stall because the TCC is inoperative in first gear. (correct me if that'...
1998 Chevrolet K1500 Cheyenne 5.7L Poor Idle Quality VIN: 2GCEK19R5W
Vehicle from another shop, engine has high idle(2000rpm) most of the time, key cycle or cold sit may idle ok for 5min after driving sticks in high again. Iac was aftermarket we replaced unit with a delco same problem. votage test to and from pcm appear to be o... Trouble codes: P0101, P1509 (Iac system high), P1336 (ckp system high variation)
1999 Chevrolet S10 LS 4.3L Poor Fuel Economy VIN: 1GCCT19W2X
i have a 99 chevy s10 4.3 zr2 has very excessive neg. fuel trim % around -17% short around 0 to 3% how to fix
1999 Chevrolet S10 2.2L Stop Lights, Turn Signal Lamp VIN: 1GCCS1444W
Hi iATN members, have a truck that has the brake lights stay on (Rear Right), and turn signal light (Right Side) stays on but does not blink if you turn signal to the right side. Left side works fine. 4 way Hazard stays on without flashing. Electrical diagram ...
2002 Chevrolet Silverado 2500 HD 6.6L MIL Lamp on, ABS and BRAKE lites VIN: 1GCHK23132
The problem started with a shorted positive battery cable which welded itself to the transmission cooler lines just ahead of the starter. The current flow was so high that one of the negative cables actually caught fire. Obviously, the truck was towed to us an... Trouble codes: U1000 (Class 2 Communication Error), P0571 (Brake cruise switch), P1631 (Theft system error)
2003 Chevrolet Impala 3.4L right front corner VIN: 2G1WF52E83
This car is driven for a buisness, it was also in a bad accident on left side. The car has a bad poping in front suspension on right side. I have found the axel\bearing nut loose twice and had to tighten. It does not matter if the car is turnnig,braking,while ...
2004 Chevrolet Silverado 1500 LS 5.3L heated seats VIN: 2GCEK13T94
When seat heaters are turned on they start to get warm and shut off this happens when one or both seats are used
1997 Geo Metro 1.0L MIL Lamp on VIN: 2C1MR2260V
po420 cat eff. have 1.27v on scanner back probe pcm had 4.35v at yellow wire (02 sense) if pull terminal out of pcm volts comming from pcm. are there any flashes or what direction need to go? thanks for any help duane Trouble codes: P0420 (catalyst eff.)
1999 GMC C2500 Sierra SL 5.7L MIL Lamp on VIN: 1FM54JN76G
I had a problem like this one time and adjusted the distributor and the problem went away but this time no luck yet. Trouble codes: P1345 (CMPCK Corelation)
2003 GMC Sierra 2500 HD SLE 6.6L speedo VIN: 1GTHK23193
Can't find any real info. I have a GMC truck that the speedo is inop at times, sometimes it bounces and sometimes it is completely dead. When i monitor pids for the speed sensors everything is ok. The trucks runs and shifts good, there are no other concerns wi...
1996 Oldsmobile Cutlass Ciera 3.1L Hesitation, Cuts out, Stall VIN: 1G3AG54N7P
The owner reported a stalling, miss when cold. When you try to move the car it stalls when cold, after it is warmed up, the car does not stall, but it has no power. I disconnected the MAF sensor, the engine check light comes on. The car has very normal power a...
1996 Oldsmobile LSS 3.8L Stall VIN: 1G3HY52K3T
This car has had an ongoing history of intermittent stalling for several months. A couple of times a day it quietly dies on decel and you notice it only when you try to turn the steering wheel unless you happen to be looking at the dash. It belongs to an older... Trouble codes: B1023, B1035
1999 Oldsmobile 88 Royale 3.8L Misfire VIN: 1G3HN52K8X
thanks in advance for taking time to read this post.we have a 3.8 that we did a head job on customer got it hot.we replaced head gaskests had heads milled and checked for cracks.we put vehicle back together and cant get rid of cyl no 3 misfire,we have spark an... Trouble codes: 300 (cylinder 3 misfire)
1993 Pontiac Trans Sport 3.8L Surge, starts in 2nd gear VIN: 1GMDUO6L8P
vehicle starts off in 2nd gear, intermittently, when tcc locks up cause vehicle to surge. check engine light will come and and off as it pleases. codes related to cruise do not light up ses. does code 99(power management problem) is it some sort of limp mode? ... Trouble codes: 99 (power management problem), 38 (tcc brake switch), 65 (cruise control servo position sensor), 67 (faulty cruise switch), 68 (cruise command problem), 88 (pcm reset)

Fixes & Summaries for GM
Fix/Summary Answers
1995 Cadillac Eldorado ETC 4.6L Blower Motor VIN: 1G6ET1299S
FIXED. Thanks to Dan, Alan, Allen, Kenneth, Dean and Reid for your time. Needed a new blower motor. Simple detail overlooked but unknown to us---Car must be running at time of test. Alldata coveniently left that step out of our equation. Dean, yes we did go to...
1995 Cadillac DeVille 4.9L ride control VIN: 1ASDEW4345
Thank you to all that replied. You are able to disable the light without causing any problems with the ride control. If you follow the procedure for installing a relay outlined in the gm tsb you must also unplug the front struts. Thanks again.
1989 Chevrolet Motorhome 7.4L Power Steering VIN: 1GBKP37WXK
Thanks to all that responded to my request. Some suggestions supplied were that the pressure was too low, this was not exactly the condition but almost. To repair it the system was flushed with some power steering flush from BG & then low climate fluid was the...
1992 Chevrolet S10 2.5L Poor Idle Quality, Surge, Stall VIN: 1GBCS10AXP
Fix was a new computer. Short term trim settled in a 89-90, which I know is low of the 128 ideal, but is about as good as I've come to expect on vehicles of this age, trim comes right up off idle. I had unplugged the egr and verified map performance, sorry, fo... Trouble codes: 44 (lean exhaust).
1992 Chevrolet Lumina APV 3.8L Cuts out, Misfire, MIL Lamp on VIN: 1GNDU06L7N
Well ain't this business FUN!!! Nobody out there will beleive what fixed this car except possibly Kenny Andrews who had similar problem in Sept 2000.(Check the archives for 94 Lumina 3.8 code p0341) I myself looked at that post and just figured that he must ha... Trouble codes: 018 (Crank-cam error).
1995 Chevrolet Monte Carlo LS 3.1L Misfire VIN: 2G1WW12M9S
Thank you everyone for all the help on this vehicle. First I found 2 new plug wires defective and one injector. Replace all defective parts and it runs like new. Thanks again for all the reponses and ideas.
1995 Chevrolet Lumina LS 3.1L 1st Gear & Overdrive VIN: 2G1WN52MXS
Thank You All For Your Quick Responses. James [...] Alabama Hit It On The Head. The TCS Fuse Was Blown. I Guess It Blew Discon Unhooking The Battery. The Old Transmission had 1st It Was Slipping Really Bad In 3rd. Thanks Again
1996 Chevrolet S10 LS 2.2L Poor Idle Quality, Hesitation, No Power VIN: 1GCCS1942T
Thanks to all who helped. I over looked this problem because compression seemed to be good on all cyls. I assumed that since compression was good then valve timing must be right therefore the timing marks on the cam and crank must be right. WRONG. Thanks to Da... Trouble codes: P0108.
1996 Chevrolet Astro 4.3L High Idle VIN: 1GNDM19W7T
One of the four wires from the PCM to the IAC was open?? I just ran another wire and that fixed the problem. Wiring harness problems are rare as compared to component failures. I should have checked for continuity before asking for help. Most of the replies I ... Trouble codes: P1509 (IAC System High Rpm).
1998 Chevrolet S10 2.2L Poor Idle Quality, Cuts out, Misfire, MIL Lamp on VIN: 1GCCS1447W
Problem has not reoccured for customer but one more time, all the information and circumstances were pretty close to the original complaint. Testing of all sensors and wiring are OK. My final conclusion is the the PCM is at fault but the customer will not repl... Trouble codes: P0200 (Injector circuit fault), P0302 (Misfire 2).
2002 Chevrolet Avalanche 1500 5.3L Tach, gauges, and driver alert system VIN: 3GNEK13TS2
I apologize for not closing earlier. This truck left us unfixed. All the suggestions were great and things we hadn't tried. Thanks to all who took the time to write. To my knowledge, the Avalanche is STILL at the dealer. If I learn more, I'll post to anyone in...
2004 Chevrolet Silverado 2500 HD 6.6L A/C Vents, Defrost VIN: 1GCHK29244
First of all thanks for all the replies the fix was after the control head was installed the computer had to be reprogram and now everything is working find thanks again.
1992 Geo Metro 1.0L no 1-2 unless manually shift VIN: 2C1MR6465N
We replaced the transmission module. The pcm recieves information from the module. Once we plugged the module in, the vehicle shifted normal. Thanks to the few that responded. Iatn is a valuable tool and a great asset to us independant shops!
1996 GMC C1500 Suburban 5.7L MIL Lamp on VIN: 1GKEC16R5T
Thank you to everyones reponses on the problem. After testing the system I found a oxygen sensor wire with one strand sticking out of the case and it was rubbing on topof the transmission housing causing the MIL to come on. I found it by following the wire by ... Trouble codes: P0161.
1999 GMC Sierra 1500 SL 4.3L Misfire VIN: 1GTEC1AW6X
Thank you for all your efforts. In the end this vehicle was fixed by replacing the distributor. Trouble codes: P0300.
2000 GMC Safari SL 4.3L Hesitation, Surge, no powert VIN: 1GKDM19W1Y
Thanks to all who posted. Especially Jim [...] who nailed it. After repairing the MAF sensor wires, I didn't think I could also have a bad MAF sensor. But it did. I disconnected the MAF sensor and the vehicle ran great. Replaced the sensor and all is good!
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