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International Automotive Technicians Network
Prev Professional Automotive Repair Technical Discussions for March 28, 2013
International Automotive Technicians' Network (iATN) - Members Only
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Open Help Requests for GM
Help Request Answers
1995 Buick Riviera 3.8L Poor Idle Quality, Misfire VIN: 1G4GD22K3S
Vehicle came into the shop running very rough at idle. We hooked up scan tool and found the the stft 182 counts and ltft 149 counts with an o2 sensor reading of 13 MV. Idle smooths when propane is added to air stream and fuel trims come down with o2 reading in... Trouble codes: P0740, P0171, P0131
2000 Buick Regal LS 3.8L Trac Control VIN: 2G4WB55KXY
Looking for information on the Variable Effort Steering. I'm getting a code c1241. I'm also getting a c1232 left speed sensor open or shorted. When monitoring the left sensor with a scan tool it shows as good. Also when cycling the ignition key from off to on ...
1996 Chevrolet Lumina 3.1L No Start, Poor Idle Quality, Surge, Stall, Misfire, MIL Lamp on VIN: 2G1WL52M0T
This car came in just over a week ago for a surge/misfire issue. Car ran ok so we went to the plugs. Original plugs so they were changed, test drove and all was good? Cuat. picked up car made a couple blocks and the surge/misfire was back and the SES light cam... Trouble codes: P0131 (low o2 activity), P0171 (lean bank 1), P0300 (multiple misfire)
2002 Chevrolet Avalanche 1500 5.3L Misfire, MIL Lamp on VIN: 3GNEC13T32
this truck came in with a steady misfire cylinders 5 and 6 more pronounce cyl 6 we swaped the injector #3 to 5 and 4 to 6 no change installed a new coil,wire and spark plug took compression test 150 lbs on all cylinders the injector signal looks good also remo... Trouble codes: P0305, P00, 306 (misfire cylinder number 6)
2004 Chevrolet Malibu LS 3.5L Rear VIN: 1G1ZT548X4
This malibu has a rattle in the rear end going over small or large bumps, you can hear it as slow as ten mph. It sounds just like a sway bar link rattle. Its not a sway bar we removed it noise is still there. All control arm and trailing arm bushings are good....
2005 Chevrolet Trailblazer LS 4.2L Mechanical VIN: 1GNES16S45
Customer brought this Trailblazer in for a noise. Put on the rack and ticking noise sounded like coming from the transmission pump area. Dropped pan and there was a lot of metal shavings in the pan. Pulled transmission tore down and found wear on the converter...
2007 Chevrolet Avalanche LTZ 5.3L Misfire VIN: 3GNFK12347
This engine only misfires on #5 cylinder when the computer commands 4-cylinder operation mode. Once it trips the code P0305, it won't command 4-cylinder operation and doesn't miss again. Not sure if you can feel the misfire when it acts up because it runs roug... Trouble codes: P0300 (multiple cylinder misfire), P0305 (Cylinder 5 misfire), P0171 (lean bank 1), P0175 (rich bank 2)
2007 Chevrolet Impala LS 3.5L No Start, died while driving VIN: 2G1WB58N17
this impala was towed in. died at cruise. cranks but no start. runs on carb spray in booster nipple. have 55 psi fuel pressure. have 12 volts to injectors on pink/black wire. have no ground signal to any injectors from ecm. tried new factory crank sensor made ...
2003 GMC Envoy XL SLT 5.3L Engine VIN: 1GKET16P43
Hi everyone and thanks in advance for any help. A customer brought me her recently purchased 2003 Envoy XL (5.3 L). Her complaint was no heat. I immediately checked the coolant level and found it to be 3 litres low on Dexcool. As soon as I diagnosed this a lig...
2004 GMC Envoy SLE 4.2L Mechanical VIN: 1GKDT13SX4
Hey guys p0410 replaced pump i heard it go on for a second is this normal i know could be a dumb question and if so is this how it works thanks guys
2000 Pontiac Grand Am SE 2.4L Parking Lights VIN: 1G2NF52TXY
Need wiring diagram right side fuse block and or pin out for parking light circuit for right side fuse block to parking lights. And or help on where to look for short
2002 Pontiac Grand Prix GT 3.8L Hard start VIN: 1G2WP52K32
Hi Guys, This car came for a hard start and a stalling while stopped.No codes stored. Traced problem to no injector pulse for about 3 seconds of cranking. Checked grounds ( voltage drop),everything appears to be operating normally. I have no scope at the momen...

Fixes & Summaries for GM
Fix/Summary Answers
1991 Buick Park Avenue 3.8L No crank VIN: 1G4CW53L1M
Thanks for everyone who took time to reply. The final fix was making a resistor of equal value to that in the key. A comedy of errors caused me to make a new resistor. First the origonal resistor I made did indeed break causing an open circuit and secondly spl...
2001 Buick LeSabre Custom 3.8L Excessive Emissions, No Start, Poor Idle Quality, Hesitation, Surge, Cuts out, Stall, Misfire VIN: 1G4HP54K21
Thanks for so many replies. We ran test after test. We followed up on all responses even though we had as stated already checked some of them. We called Identifix and eventually found our issue. The aftermarket harmonic balancer the customer had installed was ... Trouble codes: 1374 (Cam/Crank correlation).
2006 Buick Rendezvous CXL 3.5L 5 volt reference VIN: 3G5DB03L26
I found connector C305 outside under the drivers seat holding water/salt after it was unplugged, literally water came running out. I could not find any breaches in the seals though and there is two other connectors attatched to it that had no moisture intrusi... Trouble codes: P0641 (5 volt reference circuit 1).
1994 Chevrolet Cavalier RS 3.1L Poor Idle Quality, Hesitation VIN: 1G1JC84T1R
Before reading any replies, we decided to try replacing the ignition module and coils on the engine since we keep good used spares on hand. This did nothing except waste a few hours time! So on everyones advice, I popped the upper plenum TOTALLY off (as in of...
2000 Chevrolet Cavalier 2.2L Unknown VIN: 1G1JC5244Y
The vehicle had a small transmission line leak. The fluid was low. I replaced the lines and topped off the fluid and all is well. Thank you all for your help. You guys are the greatest.
2002 Chevrolet Trailblazer LS 4.2L 4x4 VIN: 1GNDT13S22
well I decided to fix the c0379 first that ended up being an acuator ( water damage ) cv shaft ( bearing in acuator housing destroyed ) and replaced the housing with shift fork gears etc. destroyed internally. That got the front axle to work via snapo...
2004 Chevrolet Suburban 1500 LS 5.3L Rt Outside Mirror VIN: 3GNFK16Z84
Talked to dealer and they said it had to be programmed but Mitchell and Alldata say no.Only if truck has camper mirrors. I disconnected battery for 10 min. and corrected problem. Thanks for all your help.
2005 Chevrolet Astro 4.3L Fuel & Batt gauges, warning lights, PRNDL VIN: 1GCDM19X45
I called my customer to schedule another appointment to perform some of the tests recommended by other IATN members. He said that "the instrument panel was acting normal as of three days ago". The van belongs to an electrical contractor I work for a lot so t...
2006 Chevrolet Impala LTZ 3.9L Heat VIN: 2G1WU58116
Thanks to all who replied, The coolant was low but much more than I first thought, when I first added it didn't take much, but after all the replies about how hard it is to get air out because heater hoses are higher than cap I decided to remove heater hoses a...
1999 GMC K1500 Suburban SLE 5.7L MIL Lamp on VIN: 1GKFK16R5X
Replaced Crank Sensor So Far Good! Thank You! Than Goodness My Customers Are Understanding, Trouble codes: 1351 (Ignition Coil Circuit High Voltage).
2007 GMC Acadia SLE 3.6L MIL Lamp on VIN: 1GKER137X7
Oak guys thanks for all your help, the customer is short on many and she is not going to fix the vehicle at this time, but the funny part is when they say is to much many i am going to sell it, thanks everyone Trouble codes: P0016 (Crankshaft Position CKP - Intake Camshaft Position CMP Correlation Bank 1).
2002 Saturn SL2 1.9L Engine VIN: 1G8ZK52732
Hello every one, got to the bottom of this mess finally. I did check all the sensors that could cause the problem all had good reference voltage and good signal return. found bad connection at the eic module ground an the engine ground at the back of the engin...
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